v4.19.13 snapshot.
diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
new file mode 100644
index 0000000..3784118
--- /dev/null
+++ b/drivers/iio/adc/stm32-adc.c
@@ -0,0 +1,2006 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This file is part of STM32 ADC driver
+ *
+ * Copyright (C) 2016, STMicroelectronics - All Rights Reserved
+ * Author: Fabrice Gasnier <fabrice.gasnier@st.com>.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/timer/stm32-lptim-trigger.h>
+#include <linux/iio/timer/stm32-timer-trigger.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+#include "stm32-adc-core.h"
+
+/* STM32F4 - Registers for each ADC instance */
+#define STM32F4_ADC_SR 0x00
+#define STM32F4_ADC_CR1 0x04
+#define STM32F4_ADC_CR2 0x08
+#define STM32F4_ADC_SMPR1 0x0C
+#define STM32F4_ADC_SMPR2 0x10
+#define STM32F4_ADC_HTR 0x24
+#define STM32F4_ADC_LTR 0x28
+#define STM32F4_ADC_SQR1 0x2C
+#define STM32F4_ADC_SQR2 0x30
+#define STM32F4_ADC_SQR3 0x34
+#define STM32F4_ADC_JSQR 0x38
+#define STM32F4_ADC_JDR1 0x3C
+#define STM32F4_ADC_JDR2 0x40
+#define STM32F4_ADC_JDR3 0x44
+#define STM32F4_ADC_JDR4 0x48
+#define STM32F4_ADC_DR 0x4C
+
+/* STM32F4_ADC_SR - bit fields */
+#define STM32F4_STRT BIT(4)
+#define STM32F4_EOC BIT(1)
+
+/* STM32F4_ADC_CR1 - bit fields */
+#define STM32F4_RES_SHIFT 24
+#define STM32F4_RES_MASK GENMASK(25, 24)
+#define STM32F4_SCAN BIT(8)
+#define STM32F4_EOCIE BIT(5)
+
+/* STM32F4_ADC_CR2 - bit fields */
+#define STM32F4_SWSTART BIT(30)
+#define STM32F4_EXTEN_SHIFT 28
+#define STM32F4_EXTEN_MASK GENMASK(29, 28)
+#define STM32F4_EXTSEL_SHIFT 24
+#define STM32F4_EXTSEL_MASK GENMASK(27, 24)
+#define STM32F4_EOCS BIT(10)
+#define STM32F4_DDS BIT(9)
+#define STM32F4_DMA BIT(8)
+#define STM32F4_ADON BIT(0)
+
+/* STM32H7 - Registers for each ADC instance */
+#define STM32H7_ADC_ISR 0x00
+#define STM32H7_ADC_IER 0x04
+#define STM32H7_ADC_CR 0x08
+#define STM32H7_ADC_CFGR 0x0C
+#define STM32H7_ADC_SMPR1 0x14
+#define STM32H7_ADC_SMPR2 0x18
+#define STM32H7_ADC_PCSEL 0x1C
+#define STM32H7_ADC_SQR1 0x30
+#define STM32H7_ADC_SQR2 0x34
+#define STM32H7_ADC_SQR3 0x38
+#define STM32H7_ADC_SQR4 0x3C
+#define STM32H7_ADC_DR 0x40
+#define STM32H7_ADC_DIFSEL 0xC0
+#define STM32H7_ADC_CALFACT 0xC4
+#define STM32H7_ADC_CALFACT2 0xC8
+
+/* STM32H7_ADC_ISR - bit fields */
+#define STM32MP1_VREGREADY BIT(12)
+#define STM32H7_EOC BIT(2)
+#define STM32H7_ADRDY BIT(0)
+
+/* STM32H7_ADC_IER - bit fields */
+#define STM32H7_EOCIE STM32H7_EOC
+
+/* STM32H7_ADC_CR - bit fields */
+#define STM32H7_ADCAL BIT(31)
+#define STM32H7_ADCALDIF BIT(30)
+#define STM32H7_DEEPPWD BIT(29)
+#define STM32H7_ADVREGEN BIT(28)
+#define STM32H7_LINCALRDYW6 BIT(27)
+#define STM32H7_LINCALRDYW5 BIT(26)
+#define STM32H7_LINCALRDYW4 BIT(25)
+#define STM32H7_LINCALRDYW3 BIT(24)
+#define STM32H7_LINCALRDYW2 BIT(23)
+#define STM32H7_LINCALRDYW1 BIT(22)
+#define STM32H7_ADCALLIN BIT(16)
+#define STM32H7_BOOST BIT(8)
+#define STM32H7_ADSTP BIT(4)
+#define STM32H7_ADSTART BIT(2)
+#define STM32H7_ADDIS BIT(1)
+#define STM32H7_ADEN BIT(0)
+
+/* STM32H7_ADC_CFGR bit fields */
+#define STM32H7_EXTEN_SHIFT 10
+#define STM32H7_EXTEN_MASK GENMASK(11, 10)
+#define STM32H7_EXTSEL_SHIFT 5
+#define STM32H7_EXTSEL_MASK GENMASK(9, 5)
+#define STM32H7_RES_SHIFT 2
+#define STM32H7_RES_MASK GENMASK(4, 2)
+#define STM32H7_DMNGT_SHIFT 0
+#define STM32H7_DMNGT_MASK GENMASK(1, 0)
+
+enum stm32h7_adc_dmngt {
+ STM32H7_DMNGT_DR_ONLY, /* Regular data in DR only */
+ STM32H7_DMNGT_DMA_ONESHOT, /* DMA one shot mode */
+ STM32H7_DMNGT_DFSDM, /* DFSDM mode */
+ STM32H7_DMNGT_DMA_CIRC, /* DMA circular mode */
+};
+
+/* STM32H7_ADC_CALFACT - bit fields */
+#define STM32H7_CALFACT_D_SHIFT 16
+#define STM32H7_CALFACT_D_MASK GENMASK(26, 16)
+#define STM32H7_CALFACT_S_SHIFT 0
+#define STM32H7_CALFACT_S_MASK GENMASK(10, 0)
+
+/* STM32H7_ADC_CALFACT2 - bit fields */
+#define STM32H7_LINCALFACT_SHIFT 0
+#define STM32H7_LINCALFACT_MASK GENMASK(29, 0)
+
+/* Number of linear calibration shadow registers / LINCALRDYW control bits */
+#define STM32H7_LINCALFACT_NUM 6
+
+/* BOOST bit must be set on STM32H7 when ADC clock is above 20MHz */
+#define STM32H7_BOOST_CLKRATE 20000000UL
+
+#define STM32_ADC_CH_MAX 20 /* max number of channels */
+#define STM32_ADC_CH_SZ 10 /* max channel name size */
+#define STM32_ADC_MAX_SQ 16 /* SQ1..SQ16 */
+#define STM32_ADC_MAX_SMP 7 /* SMPx range is [0..7] */
+#define STM32_ADC_TIMEOUT_US 100000
+#define STM32_ADC_TIMEOUT (msecs_to_jiffies(STM32_ADC_TIMEOUT_US / 1000))
+
+#define STM32_DMA_BUFFER_SIZE PAGE_SIZE
+
+/* External trigger enable */
+enum stm32_adc_exten {
+ STM32_EXTEN_SWTRIG,
+ STM32_EXTEN_HWTRIG_RISING_EDGE,
+ STM32_EXTEN_HWTRIG_FALLING_EDGE,
+ STM32_EXTEN_HWTRIG_BOTH_EDGES,
+};
+
+/* extsel - trigger mux selection value */
+enum stm32_adc_extsel {
+ STM32_EXT0,
+ STM32_EXT1,
+ STM32_EXT2,
+ STM32_EXT3,
+ STM32_EXT4,
+ STM32_EXT5,
+ STM32_EXT6,
+ STM32_EXT7,
+ STM32_EXT8,
+ STM32_EXT9,
+ STM32_EXT10,
+ STM32_EXT11,
+ STM32_EXT12,
+ STM32_EXT13,
+ STM32_EXT14,
+ STM32_EXT15,
+ STM32_EXT16,
+ STM32_EXT17,
+ STM32_EXT18,
+ STM32_EXT19,
+ STM32_EXT20,
+};
+
+/**
+ * struct stm32_adc_trig_info - ADC trigger info
+ * @name: name of the trigger, corresponding to its source
+ * @extsel: trigger selection
+ */
+struct stm32_adc_trig_info {
+ const char *name;
+ enum stm32_adc_extsel extsel;
+};
+
+/**
+ * struct stm32_adc_calib - optional adc calibration data
+ * @calfact_s: Calibration offset for single ended channels
+ * @calfact_d: Calibration offset in differential
+ * @lincalfact: Linearity calibration factor
+ */
+struct stm32_adc_calib {
+ u32 calfact_s;
+ u32 calfact_d;
+ u32 lincalfact[STM32H7_LINCALFACT_NUM];
+};
+
+/**
+ * stm32_adc_regs - stm32 ADC misc registers & bitfield desc
+ * @reg: register offset
+ * @mask: bitfield mask
+ * @shift: left shift
+ */
+struct stm32_adc_regs {
+ int reg;
+ int mask;
+ int shift;
+};
+
+/**
+ * stm32_adc_regspec - stm32 registers definition, compatible dependent data
+ * @dr: data register offset
+ * @ier_eoc: interrupt enable register & eocie bitfield
+ * @isr_eoc: interrupt status register & eoc bitfield
+ * @sqr: reference to sequence registers array
+ * @exten: trigger control register & bitfield
+ * @extsel: trigger selection register & bitfield
+ * @res: resolution selection register & bitfield
+ * @smpr: smpr1 & smpr2 registers offset array
+ * @smp_bits: smpr1 & smpr2 index and bitfields
+ */
+struct stm32_adc_regspec {
+ const u32 dr;
+ const struct stm32_adc_regs ier_eoc;
+ const struct stm32_adc_regs isr_eoc;
+ const struct stm32_adc_regs *sqr;
+ const struct stm32_adc_regs exten;
+ const struct stm32_adc_regs extsel;
+ const struct stm32_adc_regs res;
+ const u32 smpr[2];
+ const struct stm32_adc_regs *smp_bits;
+};
+
+struct stm32_adc;
+
+/**
+ * stm32_adc_cfg - stm32 compatible configuration data
+ * @regs: registers descriptions
+ * @adc_info: per instance input channels definitions
+ * @trigs: external trigger sources
+ * @clk_required: clock is required
+ * @has_vregready: vregready status flag presence
+ * @selfcalib: optional routine for self-calibration
+ * @prepare: optional prepare routine (power-up, enable)
+ * @start_conv: routine to start conversions
+ * @stop_conv: routine to stop conversions
+ * @unprepare: optional unprepare routine (disable, power-down)
+ * @smp_cycles: programmable sampling time (ADC clock cycles)
+ */
+struct stm32_adc_cfg {
+ const struct stm32_adc_regspec *regs;
+ const struct stm32_adc_info *adc_info;
+ struct stm32_adc_trig_info *trigs;
+ bool clk_required;
+ bool has_vregready;
+ int (*selfcalib)(struct stm32_adc *);
+ int (*prepare)(struct stm32_adc *);
+ void (*start_conv)(struct stm32_adc *, bool dma);
+ void (*stop_conv)(struct stm32_adc *);
+ void (*unprepare)(struct stm32_adc *);
+ const unsigned int *smp_cycles;
+};
+
+/**
+ * struct stm32_adc - private data of each ADC IIO instance
+ * @common: reference to ADC block common data
+ * @offset: ADC instance register offset in ADC block
+ * @cfg: compatible configuration data
+ * @completion: end of single conversion completion
+ * @buffer: data buffer
+ * @clk: clock for this adc instance
+ * @irq: interrupt for this adc instance
+ * @lock: spinlock
+ * @bufi: data buffer index
+ * @num_conv: expected number of scan conversions
+ * @res: data resolution (e.g. RES bitfield value)
+ * @trigger_polarity: external trigger polarity (e.g. exten)
+ * @dma_chan: dma channel
+ * @rx_buf: dma rx buffer cpu address
+ * @rx_dma_buf: dma rx buffer bus address
+ * @rx_buf_sz: dma rx buffer size
+ * @difsel bitmask to set single-ended/differential channel
+ * @pcsel bitmask to preselect channels on some devices
+ * @smpr_val: sampling time settings (e.g. smpr1 / smpr2)
+ * @cal: optional calibration data on some devices
+ * @chan_name: channel name array
+ */
+struct stm32_adc {
+ struct stm32_adc_common *common;
+ u32 offset;
+ const struct stm32_adc_cfg *cfg;
+ struct completion completion;
+ u16 buffer[STM32_ADC_MAX_SQ];
+ struct clk *clk;
+ int irq;
+ spinlock_t lock; /* interrupt lock */
+ unsigned int bufi;
+ unsigned int num_conv;
+ u32 res;
+ u32 trigger_polarity;
+ struct dma_chan *dma_chan;
+ u8 *rx_buf;
+ dma_addr_t rx_dma_buf;
+ unsigned int rx_buf_sz;
+ u32 difsel;
+ u32 pcsel;
+ u32 smpr_val[2];
+ struct stm32_adc_calib cal;
+ char chan_name[STM32_ADC_CH_MAX][STM32_ADC_CH_SZ];
+};
+
+struct stm32_adc_diff_channel {
+ u32 vinp;
+ u32 vinn;
+};
+
+/**
+ * struct stm32_adc_info - stm32 ADC, per instance config data
+ * @max_channels: Number of channels
+ * @resolutions: available resolutions
+ * @num_res: number of available resolutions
+ */
+struct stm32_adc_info {
+ int max_channels;
+ const unsigned int *resolutions;
+ const unsigned int num_res;
+};
+
+static const unsigned int stm32f4_adc_resolutions[] = {
+ /* sorted values so the index matches RES[1:0] in STM32F4_ADC_CR1 */
+ 12, 10, 8, 6,
+};
+
+/* stm32f4 can have up to 16 channels */
+static const struct stm32_adc_info stm32f4_adc_info = {
+ .max_channels = 16,
+ .resolutions = stm32f4_adc_resolutions,
+ .num_res = ARRAY_SIZE(stm32f4_adc_resolutions),
+};
+
+static const unsigned int stm32h7_adc_resolutions[] = {
+ /* sorted values so the index matches RES[2:0] in STM32H7_ADC_CFGR */
+ 16, 14, 12, 10, 8,
+};
+
+/* stm32h7 can have up to 20 channels */
+static const struct stm32_adc_info stm32h7_adc_info = {
+ .max_channels = STM32_ADC_CH_MAX,
+ .resolutions = stm32h7_adc_resolutions,
+ .num_res = ARRAY_SIZE(stm32h7_adc_resolutions),
+};
+
+/**
+ * stm32f4_sq - describe regular sequence registers
+ * - L: sequence len (register & bit field)
+ * - SQ1..SQ16: sequence entries (register & bit field)
+ */
+static const struct stm32_adc_regs stm32f4_sq[STM32_ADC_MAX_SQ + 1] = {
+ /* L: len bit field description to be kept as first element */
+ { STM32F4_ADC_SQR1, GENMASK(23, 20), 20 },
+ /* SQ1..SQ16 registers & bit fields (reg, mask, shift) */
+ { STM32F4_ADC_SQR3, GENMASK(4, 0), 0 },
+ { STM32F4_ADC_SQR3, GENMASK(9, 5), 5 },
+ { STM32F4_ADC_SQR3, GENMASK(14, 10), 10 },
+ { STM32F4_ADC_SQR3, GENMASK(19, 15), 15 },
+ { STM32F4_ADC_SQR3, GENMASK(24, 20), 20 },
+ { STM32F4_ADC_SQR3, GENMASK(29, 25), 25 },
+ { STM32F4_ADC_SQR2, GENMASK(4, 0), 0 },
+ { STM32F4_ADC_SQR2, GENMASK(9, 5), 5 },
+ { STM32F4_ADC_SQR2, GENMASK(14, 10), 10 },
+ { STM32F4_ADC_SQR2, GENMASK(19, 15), 15 },
+ { STM32F4_ADC_SQR2, GENMASK(24, 20), 20 },
+ { STM32F4_ADC_SQR2, GENMASK(29, 25), 25 },
+ { STM32F4_ADC_SQR1, GENMASK(4, 0), 0 },
+ { STM32F4_ADC_SQR1, GENMASK(9, 5), 5 },
+ { STM32F4_ADC_SQR1, GENMASK(14, 10), 10 },
+ { STM32F4_ADC_SQR1, GENMASK(19, 15), 15 },
+};
+
+/* STM32F4 external trigger sources for all instances */
+static struct stm32_adc_trig_info stm32f4_adc_trigs[] = {
+ { TIM1_CH1, STM32_EXT0 },
+ { TIM1_CH2, STM32_EXT1 },
+ { TIM1_CH3, STM32_EXT2 },
+ { TIM2_CH2, STM32_EXT3 },
+ { TIM2_CH3, STM32_EXT4 },
+ { TIM2_CH4, STM32_EXT5 },
+ { TIM2_TRGO, STM32_EXT6 },
+ { TIM3_CH1, STM32_EXT7 },
+ { TIM3_TRGO, STM32_EXT8 },
+ { TIM4_CH4, STM32_EXT9 },
+ { TIM5_CH1, STM32_EXT10 },
+ { TIM5_CH2, STM32_EXT11 },
+ { TIM5_CH3, STM32_EXT12 },
+ { TIM8_CH1, STM32_EXT13 },
+ { TIM8_TRGO, STM32_EXT14 },
+ {}, /* sentinel */
+};
+
+/**
+ * stm32f4_smp_bits[] - describe sampling time register index & bit fields
+ * Sorted so it can be indexed by channel number.
+ */
+static const struct stm32_adc_regs stm32f4_smp_bits[] = {
+ /* STM32F4_ADC_SMPR2: smpr[] index, mask, shift for SMP0 to SMP9 */
+ { 1, GENMASK(2, 0), 0 },
+ { 1, GENMASK(5, 3), 3 },
+ { 1, GENMASK(8, 6), 6 },
+ { 1, GENMASK(11, 9), 9 },
+ { 1, GENMASK(14, 12), 12 },
+ { 1, GENMASK(17, 15), 15 },
+ { 1, GENMASK(20, 18), 18 },
+ { 1, GENMASK(23, 21), 21 },
+ { 1, GENMASK(26, 24), 24 },
+ { 1, GENMASK(29, 27), 27 },
+ /* STM32F4_ADC_SMPR1, smpr[] index, mask, shift for SMP10 to SMP18 */
+ { 0, GENMASK(2, 0), 0 },
+ { 0, GENMASK(5, 3), 3 },
+ { 0, GENMASK(8, 6), 6 },
+ { 0, GENMASK(11, 9), 9 },
+ { 0, GENMASK(14, 12), 12 },
+ { 0, GENMASK(17, 15), 15 },
+ { 0, GENMASK(20, 18), 18 },
+ { 0, GENMASK(23, 21), 21 },
+ { 0, GENMASK(26, 24), 24 },
+};
+
+/* STM32F4 programmable sampling time (ADC clock cycles) */
+static const unsigned int stm32f4_adc_smp_cycles[STM32_ADC_MAX_SMP + 1] = {
+ 3, 15, 28, 56, 84, 112, 144, 480,
+};
+
+static const struct stm32_adc_regspec stm32f4_adc_regspec = {
+ .dr = STM32F4_ADC_DR,
+ .ier_eoc = { STM32F4_ADC_CR1, STM32F4_EOCIE },
+ .isr_eoc = { STM32F4_ADC_SR, STM32F4_EOC },
+ .sqr = stm32f4_sq,
+ .exten = { STM32F4_ADC_CR2, STM32F4_EXTEN_MASK, STM32F4_EXTEN_SHIFT },
+ .extsel = { STM32F4_ADC_CR2, STM32F4_EXTSEL_MASK,
+ STM32F4_EXTSEL_SHIFT },
+ .res = { STM32F4_ADC_CR1, STM32F4_RES_MASK, STM32F4_RES_SHIFT },
+ .smpr = { STM32F4_ADC_SMPR1, STM32F4_ADC_SMPR2 },
+ .smp_bits = stm32f4_smp_bits,
+};
+
+static const struct stm32_adc_regs stm32h7_sq[STM32_ADC_MAX_SQ + 1] = {
+ /* L: len bit field description to be kept as first element */
+ { STM32H7_ADC_SQR1, GENMASK(3, 0), 0 },
+ /* SQ1..SQ16 registers & bit fields (reg, mask, shift) */
+ { STM32H7_ADC_SQR1, GENMASK(10, 6), 6 },
+ { STM32H7_ADC_SQR1, GENMASK(16, 12), 12 },
+ { STM32H7_ADC_SQR1, GENMASK(22, 18), 18 },
+ { STM32H7_ADC_SQR1, GENMASK(28, 24), 24 },
+ { STM32H7_ADC_SQR2, GENMASK(4, 0), 0 },
+ { STM32H7_ADC_SQR2, GENMASK(10, 6), 6 },
+ { STM32H7_ADC_SQR2, GENMASK(16, 12), 12 },
+ { STM32H7_ADC_SQR2, GENMASK(22, 18), 18 },
+ { STM32H7_ADC_SQR2, GENMASK(28, 24), 24 },
+ { STM32H7_ADC_SQR3, GENMASK(4, 0), 0 },
+ { STM32H7_ADC_SQR3, GENMASK(10, 6), 6 },
+ { STM32H7_ADC_SQR3, GENMASK(16, 12), 12 },
+ { STM32H7_ADC_SQR3, GENMASK(22, 18), 18 },
+ { STM32H7_ADC_SQR3, GENMASK(28, 24), 24 },
+ { STM32H7_ADC_SQR4, GENMASK(4, 0), 0 },
+ { STM32H7_ADC_SQR4, GENMASK(10, 6), 6 },
+};
+
+/* STM32H7 external trigger sources for all instances */
+static struct stm32_adc_trig_info stm32h7_adc_trigs[] = {
+ { TIM1_CH1, STM32_EXT0 },
+ { TIM1_CH2, STM32_EXT1 },
+ { TIM1_CH3, STM32_EXT2 },
+ { TIM2_CH2, STM32_EXT3 },
+ { TIM3_TRGO, STM32_EXT4 },
+ { TIM4_CH4, STM32_EXT5 },
+ { TIM8_TRGO, STM32_EXT7 },
+ { TIM8_TRGO2, STM32_EXT8 },
+ { TIM1_TRGO, STM32_EXT9 },
+ { TIM1_TRGO2, STM32_EXT10 },
+ { TIM2_TRGO, STM32_EXT11 },
+ { TIM4_TRGO, STM32_EXT12 },
+ { TIM6_TRGO, STM32_EXT13 },
+ { TIM15_TRGO, STM32_EXT14 },
+ { TIM3_CH4, STM32_EXT15 },
+ { LPTIM1_OUT, STM32_EXT18 },
+ { LPTIM2_OUT, STM32_EXT19 },
+ { LPTIM3_OUT, STM32_EXT20 },
+ {},
+};
+
+/**
+ * stm32h7_smp_bits - describe sampling time register index & bit fields
+ * Sorted so it can be indexed by channel number.
+ */
+static const struct stm32_adc_regs stm32h7_smp_bits[] = {
+ /* STM32H7_ADC_SMPR1, smpr[] index, mask, shift for SMP0 to SMP9 */
+ { 0, GENMASK(2, 0), 0 },
+ { 0, GENMASK(5, 3), 3 },
+ { 0, GENMASK(8, 6), 6 },
+ { 0, GENMASK(11, 9), 9 },
+ { 0, GENMASK(14, 12), 12 },
+ { 0, GENMASK(17, 15), 15 },
+ { 0, GENMASK(20, 18), 18 },
+ { 0, GENMASK(23, 21), 21 },
+ { 0, GENMASK(26, 24), 24 },
+ { 0, GENMASK(29, 27), 27 },
+ /* STM32H7_ADC_SMPR2, smpr[] index, mask, shift for SMP10 to SMP19 */
+ { 1, GENMASK(2, 0), 0 },
+ { 1, GENMASK(5, 3), 3 },
+ { 1, GENMASK(8, 6), 6 },
+ { 1, GENMASK(11, 9), 9 },
+ { 1, GENMASK(14, 12), 12 },
+ { 1, GENMASK(17, 15), 15 },
+ { 1, GENMASK(20, 18), 18 },
+ { 1, GENMASK(23, 21), 21 },
+ { 1, GENMASK(26, 24), 24 },
+ { 1, GENMASK(29, 27), 27 },
+};
+
+/* STM32H7 programmable sampling time (ADC clock cycles, rounded down) */
+static const unsigned int stm32h7_adc_smp_cycles[STM32_ADC_MAX_SMP + 1] = {
+ 1, 2, 8, 16, 32, 64, 387, 810,
+};
+
+static const struct stm32_adc_regspec stm32h7_adc_regspec = {
+ .dr = STM32H7_ADC_DR,
+ .ier_eoc = { STM32H7_ADC_IER, STM32H7_EOCIE },
+ .isr_eoc = { STM32H7_ADC_ISR, STM32H7_EOC },
+ .sqr = stm32h7_sq,
+ .exten = { STM32H7_ADC_CFGR, STM32H7_EXTEN_MASK, STM32H7_EXTEN_SHIFT },
+ .extsel = { STM32H7_ADC_CFGR, STM32H7_EXTSEL_MASK,
+ STM32H7_EXTSEL_SHIFT },
+ .res = { STM32H7_ADC_CFGR, STM32H7_RES_MASK, STM32H7_RES_SHIFT },
+ .smpr = { STM32H7_ADC_SMPR1, STM32H7_ADC_SMPR2 },
+ .smp_bits = stm32h7_smp_bits,
+};
+
+/**
+ * STM32 ADC registers access routines
+ * @adc: stm32 adc instance
+ * @reg: reg offset in adc instance
+ *
+ * Note: All instances share same base, with 0x0, 0x100 or 0x200 offset resp.
+ * for adc1, adc2 and adc3.
+ */
+static u32 stm32_adc_readl(struct stm32_adc *adc, u32 reg)
+{
+ return readl_relaxed(adc->common->base + adc->offset + reg);
+}
+
+#define stm32_adc_readl_addr(addr) stm32_adc_readl(adc, addr)
+
+#define stm32_adc_readl_poll_timeout(reg, val, cond, sleep_us, timeout_us) \
+ readx_poll_timeout(stm32_adc_readl_addr, reg, val, \
+ cond, sleep_us, timeout_us)
+
+static u16 stm32_adc_readw(struct stm32_adc *adc, u32 reg)
+{
+ return readw_relaxed(adc->common->base + adc->offset + reg);
+}
+
+static void stm32_adc_writel(struct stm32_adc *adc, u32 reg, u32 val)
+{
+ writel_relaxed(val, adc->common->base + adc->offset + reg);
+}
+
+static void stm32_adc_set_bits(struct stm32_adc *adc, u32 reg, u32 bits)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&adc->lock, flags);
+ stm32_adc_writel(adc, reg, stm32_adc_readl(adc, reg) | bits);
+ spin_unlock_irqrestore(&adc->lock, flags);
+}
+
+static void stm32_adc_clr_bits(struct stm32_adc *adc, u32 reg, u32 bits)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&adc->lock, flags);
+ stm32_adc_writel(adc, reg, stm32_adc_readl(adc, reg) & ~bits);
+ spin_unlock_irqrestore(&adc->lock, flags);
+}
+
+/**
+ * stm32_adc_conv_irq_enable() - Enable end of conversion interrupt
+ * @adc: stm32 adc instance
+ */
+static void stm32_adc_conv_irq_enable(struct stm32_adc *adc)
+{
+ stm32_adc_set_bits(adc, adc->cfg->regs->ier_eoc.reg,
+ adc->cfg->regs->ier_eoc.mask);
+};
+
+/**
+ * stm32_adc_conv_irq_disable() - Disable end of conversion interrupt
+ * @adc: stm32 adc instance
+ */
+static void stm32_adc_conv_irq_disable(struct stm32_adc *adc)
+{
+ stm32_adc_clr_bits(adc, adc->cfg->regs->ier_eoc.reg,
+ adc->cfg->regs->ier_eoc.mask);
+}
+
+static void stm32_adc_set_res(struct stm32_adc *adc)
+{
+ const struct stm32_adc_regs *res = &adc->cfg->regs->res;
+ u32 val;
+
+ val = stm32_adc_readl(adc, res->reg);
+ val = (val & ~res->mask) | (adc->res << res->shift);
+ stm32_adc_writel(adc, res->reg, val);
+}
+
+/**
+ * stm32f4_adc_start_conv() - Start conversions for regular channels.
+ * @adc: stm32 adc instance
+ * @dma: use dma to transfer conversion result
+ *
+ * Start conversions for regular channels.
+ * Also take care of normal or DMA mode. Circular DMA may be used for regular
+ * conversions, in IIO buffer modes. Otherwise, use ADC interrupt with direct
+ * DR read instead (e.g. read_raw, or triggered buffer mode without DMA).
+ */
+static void stm32f4_adc_start_conv(struct stm32_adc *adc, bool dma)
+{
+ stm32_adc_set_bits(adc, STM32F4_ADC_CR1, STM32F4_SCAN);
+
+ if (dma)
+ stm32_adc_set_bits(adc, STM32F4_ADC_CR2,
+ STM32F4_DMA | STM32F4_DDS);
+
+ stm32_adc_set_bits(adc, STM32F4_ADC_CR2, STM32F4_EOCS | STM32F4_ADON);
+
+ /* Wait for Power-up time (tSTAB from datasheet) */
+ usleep_range(2, 3);
+
+ /* Software start ? (e.g. trigger detection disabled ?) */
+ if (!(stm32_adc_readl(adc, STM32F4_ADC_CR2) & STM32F4_EXTEN_MASK))
+ stm32_adc_set_bits(adc, STM32F4_ADC_CR2, STM32F4_SWSTART);
+}
+
+static void stm32f4_adc_stop_conv(struct stm32_adc *adc)
+{
+ stm32_adc_clr_bits(adc, STM32F4_ADC_CR2, STM32F4_EXTEN_MASK);
+ stm32_adc_clr_bits(adc, STM32F4_ADC_SR, STM32F4_STRT);
+
+ stm32_adc_clr_bits(adc, STM32F4_ADC_CR1, STM32F4_SCAN);
+ stm32_adc_clr_bits(adc, STM32F4_ADC_CR2,
+ STM32F4_ADON | STM32F4_DMA | STM32F4_DDS);
+}
+
+static void stm32h7_adc_start_conv(struct stm32_adc *adc, bool dma)
+{
+ enum stm32h7_adc_dmngt dmngt;
+ unsigned long flags;
+ u32 val;
+
+ if (dma)
+ dmngt = STM32H7_DMNGT_DMA_CIRC;
+ else
+ dmngt = STM32H7_DMNGT_DR_ONLY;
+
+ spin_lock_irqsave(&adc->lock, flags);
+ val = stm32_adc_readl(adc, STM32H7_ADC_CFGR);
+ val = (val & ~STM32H7_DMNGT_MASK) | (dmngt << STM32H7_DMNGT_SHIFT);
+ stm32_adc_writel(adc, STM32H7_ADC_CFGR, val);
+ spin_unlock_irqrestore(&adc->lock, flags);
+
+ stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADSTART);
+}
+
+static void stm32h7_adc_stop_conv(struct stm32_adc *adc)
+{
+ struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+ int ret;
+ u32 val;
+
+ stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADSTP);
+
+ ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
+ !(val & (STM32H7_ADSTART)),
+ 100, STM32_ADC_TIMEOUT_US);
+ if (ret)
+ dev_warn(&indio_dev->dev, "stop failed\n");
+
+ stm32_adc_clr_bits(adc, STM32H7_ADC_CFGR, STM32H7_DMNGT_MASK);
+}
+
+static int stm32h7_adc_exit_pwr_down(struct stm32_adc *adc)
+{
+ struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+ int ret;
+ u32 val;
+
+ /* Exit deep power down, then enable ADC voltage regulator */
+ stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_DEEPPWD);
+ stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADVREGEN);
+
+ if (adc->common->rate > STM32H7_BOOST_CLKRATE)
+ stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_BOOST);
+
+ /* Wait for startup time */
+ if (!adc->cfg->has_vregready) {
+ usleep_range(10, 20);
+ return 0;
+ }
+
+ ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_ISR, val,
+ val & STM32MP1_VREGREADY, 100,
+ STM32_ADC_TIMEOUT_US);
+ if (ret) {
+ stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_DEEPPWD);
+ dev_err(&indio_dev->dev, "Failed to exit power down\n");
+ }
+
+ return ret;
+}
+
+static void stm32h7_adc_enter_pwr_down(struct stm32_adc *adc)
+{
+ stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_BOOST);
+
+ /* Setting DEEPPWD disables ADC vreg and clears ADVREGEN */
+ stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_DEEPPWD);
+}
+
+static int stm32h7_adc_enable(struct stm32_adc *adc)
+{
+ struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+ int ret;
+ u32 val;
+
+ stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADEN);
+
+ /* Poll for ADRDY to be set (after adc startup time) */
+ ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_ISR, val,
+ val & STM32H7_ADRDY,
+ 100, STM32_ADC_TIMEOUT_US);
+ if (ret) {
+ stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADDIS);
+ dev_err(&indio_dev->dev, "Failed to enable ADC\n");
+ } else {
+ /* Clear ADRDY by writing one */
+ stm32_adc_set_bits(adc, STM32H7_ADC_ISR, STM32H7_ADRDY);
+ }
+
+ return ret;
+}
+
+static void stm32h7_adc_disable(struct stm32_adc *adc)
+{
+ struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+ int ret;
+ u32 val;
+
+ /* Disable ADC and wait until it's effectively disabled */
+ stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADDIS);
+ ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
+ !(val & STM32H7_ADEN), 100,
+ STM32_ADC_TIMEOUT_US);
+ if (ret)
+ dev_warn(&indio_dev->dev, "Failed to disable\n");
+}
+
+/**
+ * stm32h7_adc_read_selfcalib() - read calibration shadow regs, save result
+ * @adc: stm32 adc instance
+ */
+static int stm32h7_adc_read_selfcalib(struct stm32_adc *adc)
+{
+ struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+ int i, ret;
+ u32 lincalrdyw_mask, val;
+
+ /* Enable adc so LINCALRDYW1..6 bits are writable */
+ ret = stm32h7_adc_enable(adc);
+ if (ret)
+ return ret;
+
+ /* Read linearity calibration */
+ lincalrdyw_mask = STM32H7_LINCALRDYW6;
+ for (i = STM32H7_LINCALFACT_NUM - 1; i >= 0; i--) {
+ /* Clear STM32H7_LINCALRDYW[6..1]: transfer calib to CALFACT2 */
+ stm32_adc_clr_bits(adc, STM32H7_ADC_CR, lincalrdyw_mask);
+
+ /* Poll: wait calib data to be ready in CALFACT2 register */
+ ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
+ !(val & lincalrdyw_mask),
+ 100, STM32_ADC_TIMEOUT_US);
+ if (ret) {
+ dev_err(&indio_dev->dev, "Failed to read calfact\n");
+ goto disable;
+ }
+
+ val = stm32_adc_readl(adc, STM32H7_ADC_CALFACT2);
+ adc->cal.lincalfact[i] = (val & STM32H7_LINCALFACT_MASK);
+ adc->cal.lincalfact[i] >>= STM32H7_LINCALFACT_SHIFT;
+
+ lincalrdyw_mask >>= 1;
+ }
+
+ /* Read offset calibration */
+ val = stm32_adc_readl(adc, STM32H7_ADC_CALFACT);
+ adc->cal.calfact_s = (val & STM32H7_CALFACT_S_MASK);
+ adc->cal.calfact_s >>= STM32H7_CALFACT_S_SHIFT;
+ adc->cal.calfact_d = (val & STM32H7_CALFACT_D_MASK);
+ adc->cal.calfact_d >>= STM32H7_CALFACT_D_SHIFT;
+
+disable:
+ stm32h7_adc_disable(adc);
+
+ return ret;
+}
+
+/**
+ * stm32h7_adc_restore_selfcalib() - Restore saved self-calibration result
+ * @adc: stm32 adc instance
+ * Note: ADC must be enabled, with no on-going conversions.
+ */
+static int stm32h7_adc_restore_selfcalib(struct stm32_adc *adc)
+{
+ struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+ int i, ret;
+ u32 lincalrdyw_mask, val;
+
+ val = (adc->cal.calfact_s << STM32H7_CALFACT_S_SHIFT) |
+ (adc->cal.calfact_d << STM32H7_CALFACT_D_SHIFT);
+ stm32_adc_writel(adc, STM32H7_ADC_CALFACT, val);
+
+ lincalrdyw_mask = STM32H7_LINCALRDYW6;
+ for (i = STM32H7_LINCALFACT_NUM - 1; i >= 0; i--) {
+ /*
+ * Write saved calibration data to shadow registers:
+ * Write CALFACT2, and set LINCALRDYW[6..1] bit to trigger
+ * data write. Then poll to wait for complete transfer.
+ */
+ val = adc->cal.lincalfact[i] << STM32H7_LINCALFACT_SHIFT;
+ stm32_adc_writel(adc, STM32H7_ADC_CALFACT2, val);
+ stm32_adc_set_bits(adc, STM32H7_ADC_CR, lincalrdyw_mask);
+ ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
+ val & lincalrdyw_mask,
+ 100, STM32_ADC_TIMEOUT_US);
+ if (ret) {
+ dev_err(&indio_dev->dev, "Failed to write calfact\n");
+ return ret;
+ }
+
+ /*
+ * Read back calibration data, has two effects:
+ * - It ensures bits LINCALRDYW[6..1] are kept cleared
+ * for next time calibration needs to be restored.
+ * - BTW, bit clear triggers a read, then check data has been
+ * correctly written.
+ */
+ stm32_adc_clr_bits(adc, STM32H7_ADC_CR, lincalrdyw_mask);
+ ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
+ !(val & lincalrdyw_mask),
+ 100, STM32_ADC_TIMEOUT_US);
+ if (ret) {
+ dev_err(&indio_dev->dev, "Failed to read calfact\n");
+ return ret;
+ }
+ val = stm32_adc_readl(adc, STM32H7_ADC_CALFACT2);
+ if (val != adc->cal.lincalfact[i] << STM32H7_LINCALFACT_SHIFT) {
+ dev_err(&indio_dev->dev, "calfact not consistent\n");
+ return -EIO;
+ }
+
+ lincalrdyw_mask >>= 1;
+ }
+
+ return 0;
+}
+
+/**
+ * Fixed timeout value for ADC calibration.
+ * worst cases:
+ * - low clock frequency
+ * - maximum prescalers
+ * Calibration requires:
+ * - 131,072 ADC clock cycle for the linear calibration
+ * - 20 ADC clock cycle for the offset calibration
+ *
+ * Set to 100ms for now
+ */
+#define STM32H7_ADC_CALIB_TIMEOUT_US 100000
+
+/**
+ * stm32h7_adc_selfcalib() - Procedure to calibrate ADC (from power down)
+ * @adc: stm32 adc instance
+ * Exit from power down, calibrate ADC, then return to power down.
+ */
+static int stm32h7_adc_selfcalib(struct stm32_adc *adc)
+{
+ struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+ int ret;
+ u32 val;
+
+ ret = stm32h7_adc_exit_pwr_down(adc);
+ if (ret)
+ return ret;
+
+ /*
+ * Select calibration mode:
+ * - Offset calibration for single ended inputs
+ * - No linearity calibration (do it later, before reading it)
+ */
+ stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_ADCALDIF);
+ stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_ADCALLIN);
+
+ /* Start calibration, then wait for completion */
+ stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADCAL);
+ ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
+ !(val & STM32H7_ADCAL), 100,
+ STM32H7_ADC_CALIB_TIMEOUT_US);
+ if (ret) {
+ dev_err(&indio_dev->dev, "calibration failed\n");
+ goto pwr_dwn;
+ }
+
+ /*
+ * Select calibration mode, then start calibration:
+ * - Offset calibration for differential input
+ * - Linearity calibration (needs to be done only once for single/diff)
+ * will run simultaneously with offset calibration.
+ */
+ stm32_adc_set_bits(adc, STM32H7_ADC_CR,
+ STM32H7_ADCALDIF | STM32H7_ADCALLIN);
+ stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADCAL);
+ ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
+ !(val & STM32H7_ADCAL), 100,
+ STM32H7_ADC_CALIB_TIMEOUT_US);
+ if (ret) {
+ dev_err(&indio_dev->dev, "calibration failed\n");
+ goto pwr_dwn;
+ }
+
+ stm32_adc_clr_bits(adc, STM32H7_ADC_CR,
+ STM32H7_ADCALDIF | STM32H7_ADCALLIN);
+
+ /* Read calibration result for future reference */
+ ret = stm32h7_adc_read_selfcalib(adc);
+
+pwr_dwn:
+ stm32h7_adc_enter_pwr_down(adc);
+
+ return ret;
+}
+
+/**
+ * stm32h7_adc_prepare() - Leave power down mode to enable ADC.
+ * @adc: stm32 adc instance
+ * Leave power down mode.
+ * Configure channels as single ended or differential before enabling ADC.
+ * Enable ADC.
+ * Restore calibration data.
+ * Pre-select channels that may be used in PCSEL (required by input MUX / IO):
+ * - Only one input is selected for single ended (e.g. 'vinp')
+ * - Two inputs are selected for differential channels (e.g. 'vinp' & 'vinn')
+ */
+static int stm32h7_adc_prepare(struct stm32_adc *adc)
+{
+ int ret;
+
+ ret = stm32h7_adc_exit_pwr_down(adc);
+ if (ret)
+ return ret;
+
+ stm32_adc_writel(adc, STM32H7_ADC_DIFSEL, adc->difsel);
+
+ ret = stm32h7_adc_enable(adc);
+ if (ret)
+ goto pwr_dwn;
+
+ ret = stm32h7_adc_restore_selfcalib(adc);
+ if (ret)
+ goto disable;
+
+ stm32_adc_writel(adc, STM32H7_ADC_PCSEL, adc->pcsel);
+
+ return 0;
+
+disable:
+ stm32h7_adc_disable(adc);
+pwr_dwn:
+ stm32h7_adc_enter_pwr_down(adc);
+
+ return ret;
+}
+
+static void stm32h7_adc_unprepare(struct stm32_adc *adc)
+{
+ stm32h7_adc_disable(adc);
+ stm32h7_adc_enter_pwr_down(adc);
+}
+
+/**
+ * stm32_adc_conf_scan_seq() - Build regular channels scan sequence
+ * @indio_dev: IIO device
+ * @scan_mask: channels to be converted
+ *
+ * Conversion sequence :
+ * Apply sampling time settings for all channels.
+ * Configure ADC scan sequence based on selected channels in scan_mask.
+ * Add channels to SQR registers, from scan_mask LSB to MSB, then
+ * program sequence len.
+ */
+static int stm32_adc_conf_scan_seq(struct iio_dev *indio_dev,
+ const unsigned long *scan_mask)
+{
+ struct stm32_adc *adc = iio_priv(indio_dev);
+ const struct stm32_adc_regs *sqr = adc->cfg->regs->sqr;
+ const struct iio_chan_spec *chan;
+ u32 val, bit;
+ int i = 0;
+
+ /* Apply sampling time settings */
+ stm32_adc_writel(adc, adc->cfg->regs->smpr[0], adc->smpr_val[0]);
+ stm32_adc_writel(adc, adc->cfg->regs->smpr[1], adc->smpr_val[1]);
+
+ for_each_set_bit(bit, scan_mask, indio_dev->masklength) {
+ chan = indio_dev->channels + bit;
+ /*
+ * Assign one channel per SQ entry in regular
+ * sequence, starting with SQ1.
+ */
+ i++;
+ if (i > STM32_ADC_MAX_SQ)
+ return -EINVAL;
+
+ dev_dbg(&indio_dev->dev, "%s chan %d to SQ%d\n",
+ __func__, chan->channel, i);
+
+ val = stm32_adc_readl(adc, sqr[i].reg);
+ val &= ~sqr[i].mask;
+ val |= chan->channel << sqr[i].shift;
+ stm32_adc_writel(adc, sqr[i].reg, val);
+ }
+
+ if (!i)
+ return -EINVAL;
+
+ /* Sequence len */
+ val = stm32_adc_readl(adc, sqr[0].reg);
+ val &= ~sqr[0].mask;
+ val |= ((i - 1) << sqr[0].shift);
+ stm32_adc_writel(adc, sqr[0].reg, val);
+
+ return 0;
+}
+
+/**
+ * stm32_adc_get_trig_extsel() - Get external trigger selection
+ * @trig: trigger
+ *
+ * Returns trigger extsel value, if trig matches, -EINVAL otherwise.
+ */
+static int stm32_adc_get_trig_extsel(struct iio_dev *indio_dev,
+ struct iio_trigger *trig)
+{
+ struct stm32_adc *adc = iio_priv(indio_dev);
+ int i;
+
+ /* lookup triggers registered by stm32 timer trigger driver */
+ for (i = 0; adc->cfg->trigs[i].name; i++) {
+ /**
+ * Checking both stm32 timer trigger type and trig name
+ * should be safe against arbitrary trigger names.
+ */
+ if ((is_stm32_timer_trigger(trig) ||
+ is_stm32_lptim_trigger(trig)) &&
+ !strcmp(adc->cfg->trigs[i].name, trig->name)) {
+ return adc->cfg->trigs[i].extsel;
+ }
+ }
+
+ return -EINVAL;
+}
+
+/**
+ * stm32_adc_set_trig() - Set a regular trigger
+ * @indio_dev: IIO device
+ * @trig: IIO trigger
+ *
+ * Set trigger source/polarity (e.g. SW, or HW with polarity) :
+ * - if HW trigger disabled (e.g. trig == NULL, conversion launched by sw)
+ * - if HW trigger enabled, set source & polarity
+ */
+static int stm32_adc_set_trig(struct iio_dev *indio_dev,
+ struct iio_trigger *trig)
+{
+ struct stm32_adc *adc = iio_priv(indio_dev);
+ u32 val, extsel = 0, exten = STM32_EXTEN_SWTRIG;
+ unsigned long flags;
+ int ret;
+
+ if (trig) {
+ ret = stm32_adc_get_trig_extsel(indio_dev, trig);
+ if (ret < 0)
+ return ret;
+
+ /* set trigger source and polarity (default to rising edge) */
+ extsel = ret;
+ exten = adc->trigger_polarity + STM32_EXTEN_HWTRIG_RISING_EDGE;
+ }
+
+ spin_lock_irqsave(&adc->lock, flags);
+ val = stm32_adc_readl(adc, adc->cfg->regs->exten.reg);
+ val &= ~(adc->cfg->regs->exten.mask | adc->cfg->regs->extsel.mask);
+ val |= exten << adc->cfg->regs->exten.shift;
+ val |= extsel << adc->cfg->regs->extsel.shift;
+ stm32_adc_writel(adc, adc->cfg->regs->exten.reg, val);
+ spin_unlock_irqrestore(&adc->lock, flags);
+
+ return 0;
+}
+
+static int stm32_adc_set_trig_pol(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ unsigned int type)
+{
+ struct stm32_adc *adc = iio_priv(indio_dev);
+
+ adc->trigger_polarity = type;
+
+ return 0;
+}
+
+static int stm32_adc_get_trig_pol(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan)
+{
+ struct stm32_adc *adc = iio_priv(indio_dev);
+
+ return adc->trigger_polarity;
+}
+
+static const char * const stm32_trig_pol_items[] = {
+ "rising-edge", "falling-edge", "both-edges",
+};
+
+static const struct iio_enum stm32_adc_trig_pol = {
+ .items = stm32_trig_pol_items,
+ .num_items = ARRAY_SIZE(stm32_trig_pol_items),
+ .get = stm32_adc_get_trig_pol,
+ .set = stm32_adc_set_trig_pol,
+};
+
+/**
+ * stm32_adc_single_conv() - Performs a single conversion
+ * @indio_dev: IIO device
+ * @chan: IIO channel
+ * @res: conversion result
+ *
+ * The function performs a single conversion on a given channel:
+ * - Apply sampling time settings
+ * - Program sequencer with one channel (e.g. in SQ1 with len = 1)
+ * - Use SW trigger
+ * - Start conversion, then wait for interrupt completion.
+ */
+static int stm32_adc_single_conv(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ int *res)
+{
+ struct stm32_adc *adc = iio_priv(indio_dev);
+ const struct stm32_adc_regspec *regs = adc->cfg->regs;
+ long timeout;
+ u32 val;
+ int ret;
+
+ reinit_completion(&adc->completion);
+
+ adc->bufi = 0;
+
+ if (adc->cfg->prepare) {
+ ret = adc->cfg->prepare(adc);
+ if (ret)
+ return ret;
+ }
+
+ /* Apply sampling time settings */
+ stm32_adc_writel(adc, regs->smpr[0], adc->smpr_val[0]);
+ stm32_adc_writel(adc, regs->smpr[1], adc->smpr_val[1]);
+
+ /* Program chan number in regular sequence (SQ1) */
+ val = stm32_adc_readl(adc, regs->sqr[1].reg);
+ val &= ~regs->sqr[1].mask;
+ val |= chan->channel << regs->sqr[1].shift;
+ stm32_adc_writel(adc, regs->sqr[1].reg, val);
+
+ /* Set regular sequence len (0 for 1 conversion) */
+ stm32_adc_clr_bits(adc, regs->sqr[0].reg, regs->sqr[0].mask);
+
+ /* Trigger detection disabled (conversion can be launched in SW) */
+ stm32_adc_clr_bits(adc, regs->exten.reg, regs->exten.mask);
+
+ stm32_adc_conv_irq_enable(adc);
+
+ adc->cfg->start_conv(adc, false);
+
+ timeout = wait_for_completion_interruptible_timeout(
+ &adc->completion, STM32_ADC_TIMEOUT);
+ if (timeout == 0) {
+ ret = -ETIMEDOUT;
+ } else if (timeout < 0) {
+ ret = timeout;
+ } else {
+ *res = adc->buffer[0];
+ ret = IIO_VAL_INT;
+ }
+
+ adc->cfg->stop_conv(adc);
+
+ stm32_adc_conv_irq_disable(adc);
+
+ if (adc->cfg->unprepare)
+ adc->cfg->unprepare(adc);
+
+ return ret;
+}
+
+static int stm32_adc_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct stm32_adc *adc = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+ if (chan->type == IIO_VOLTAGE)
+ ret = stm32_adc_single_conv(indio_dev, chan, val);
+ else
+ ret = -EINVAL;
+ iio_device_release_direct_mode(indio_dev);
+ return ret;
+
+ case IIO_CHAN_INFO_SCALE:
+ if (chan->differential) {
+ *val = adc->common->vref_mv * 2;
+ *val2 = chan->scan_type.realbits;
+ } else {
+ *val = adc->common->vref_mv;
+ *val2 = chan->scan_type.realbits;
+ }
+ return IIO_VAL_FRACTIONAL_LOG2;
+
+ case IIO_CHAN_INFO_OFFSET:
+ if (chan->differential)
+ /* ADC_full_scale / 2 */
+ *val = -((1 << chan->scan_type.realbits) / 2);
+ else
+ *val = 0;
+ return IIO_VAL_INT;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static irqreturn_t stm32_adc_isr(int irq, void *data)
+{
+ struct stm32_adc *adc = data;
+ struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+ const struct stm32_adc_regspec *regs = adc->cfg->regs;
+ u32 status = stm32_adc_readl(adc, regs->isr_eoc.reg);
+
+ if (status & regs->isr_eoc.mask) {
+ /* Reading DR also clears EOC status flag */
+ adc->buffer[adc->bufi] = stm32_adc_readw(adc, regs->dr);
+ if (iio_buffer_enabled(indio_dev)) {
+ adc->bufi++;
+ if (adc->bufi >= adc->num_conv) {
+ stm32_adc_conv_irq_disable(adc);
+ iio_trigger_poll(indio_dev->trig);
+ }
+ } else {
+ complete(&adc->completion);
+ }
+ return IRQ_HANDLED;
+ }
+
+ return IRQ_NONE;
+}
+
+/**
+ * stm32_adc_validate_trigger() - validate trigger for stm32 adc
+ * @indio_dev: IIO device
+ * @trig: new trigger
+ *
+ * Returns: 0 if trig matches one of the triggers registered by stm32 adc
+ * driver, -EINVAL otherwise.
+ */
+static int stm32_adc_validate_trigger(struct iio_dev *indio_dev,
+ struct iio_trigger *trig)
+{
+ return stm32_adc_get_trig_extsel(indio_dev, trig) < 0 ? -EINVAL : 0;
+}
+
+static int stm32_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val)
+{
+ struct stm32_adc *adc = iio_priv(indio_dev);
+ unsigned int watermark = STM32_DMA_BUFFER_SIZE / 2;
+ unsigned int rx_buf_sz = STM32_DMA_BUFFER_SIZE;
+
+ /*
+ * dma cyclic transfers are used, buffer is split into two periods.
+ * There should be :
+ * - always one buffer (period) dma is working on
+ * - one buffer (period) driver can push with iio_trigger_poll().
+ */
+ watermark = min(watermark, val * (unsigned)(sizeof(u16)));
+ adc->rx_buf_sz = min(rx_buf_sz, watermark * 2 * adc->num_conv);
+
+ return 0;
+}
+
+static int stm32_adc_update_scan_mode(struct iio_dev *indio_dev,
+ const unsigned long *scan_mask)
+{
+ struct stm32_adc *adc = iio_priv(indio_dev);
+ int ret;
+
+ adc->num_conv = bitmap_weight(scan_mask, indio_dev->masklength);
+
+ ret = stm32_adc_conf_scan_seq(indio_dev, scan_mask);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int stm32_adc_of_xlate(struct iio_dev *indio_dev,
+ const struct of_phandle_args *iiospec)
+{
+ int i;
+
+ for (i = 0; i < indio_dev->num_channels; i++)
+ if (indio_dev->channels[i].channel == iiospec->args[0])
+ return i;
+
+ return -EINVAL;
+}
+
+/**
+ * stm32_adc_debugfs_reg_access - read or write register value
+ *
+ * To read a value from an ADC register:
+ * echo [ADC reg offset] > direct_reg_access
+ * cat direct_reg_access
+ *
+ * To write a value in a ADC register:
+ * echo [ADC_reg_offset] [value] > direct_reg_access
+ */
+static int stm32_adc_debugfs_reg_access(struct iio_dev *indio_dev,
+ unsigned reg, unsigned writeval,
+ unsigned *readval)
+{
+ struct stm32_adc *adc = iio_priv(indio_dev);
+
+ if (!readval)
+ stm32_adc_writel(adc, reg, writeval);
+ else
+ *readval = stm32_adc_readl(adc, reg);
+
+ return 0;
+}
+
+static const struct iio_info stm32_adc_iio_info = {
+ .read_raw = stm32_adc_read_raw,
+ .validate_trigger = stm32_adc_validate_trigger,
+ .hwfifo_set_watermark = stm32_adc_set_watermark,
+ .update_scan_mode = stm32_adc_update_scan_mode,
+ .debugfs_reg_access = stm32_adc_debugfs_reg_access,
+ .of_xlate = stm32_adc_of_xlate,
+};
+
+static unsigned int stm32_adc_dma_residue(struct stm32_adc *adc)
+{
+ struct dma_tx_state state;
+ enum dma_status status;
+
+ status = dmaengine_tx_status(adc->dma_chan,
+ adc->dma_chan->cookie,
+ &state);
+ if (status == DMA_IN_PROGRESS) {
+ /* Residue is size in bytes from end of buffer */
+ unsigned int i = adc->rx_buf_sz - state.residue;
+ unsigned int size;
+
+ /* Return available bytes */
+ if (i >= adc->bufi)
+ size = i - adc->bufi;
+ else
+ size = adc->rx_buf_sz + i - adc->bufi;
+
+ return size;
+ }
+
+ return 0;
+}
+
+static void stm32_adc_dma_buffer_done(void *data)
+{
+ struct iio_dev *indio_dev = data;
+
+ iio_trigger_poll_chained(indio_dev->trig);
+}
+
+static int stm32_adc_dma_start(struct iio_dev *indio_dev)
+{
+ struct stm32_adc *adc = iio_priv(indio_dev);
+ struct dma_async_tx_descriptor *desc;
+ dma_cookie_t cookie;
+ int ret;
+
+ if (!adc->dma_chan)
+ return 0;
+
+ dev_dbg(&indio_dev->dev, "%s size=%d watermark=%d\n", __func__,
+ adc->rx_buf_sz, adc->rx_buf_sz / 2);
+
+ /* Prepare a DMA cyclic transaction */
+ desc = dmaengine_prep_dma_cyclic(adc->dma_chan,
+ adc->rx_dma_buf,
+ adc->rx_buf_sz, adc->rx_buf_sz / 2,
+ DMA_DEV_TO_MEM,
+ DMA_PREP_INTERRUPT);
+ if (!desc)
+ return -EBUSY;
+
+ desc->callback = stm32_adc_dma_buffer_done;
+ desc->callback_param = indio_dev;
+
+ cookie = dmaengine_submit(desc);
+ ret = dma_submit_error(cookie);
+ if (ret) {
+ dmaengine_terminate_all(adc->dma_chan);
+ return ret;
+ }
+
+ /* Issue pending DMA requests */
+ dma_async_issue_pending(adc->dma_chan);
+
+ return 0;
+}
+
+static int stm32_adc_buffer_postenable(struct iio_dev *indio_dev)
+{
+ struct stm32_adc *adc = iio_priv(indio_dev);
+ int ret;
+
+ if (adc->cfg->prepare) {
+ ret = adc->cfg->prepare(adc);
+ if (ret)
+ return ret;
+ }
+
+ ret = stm32_adc_set_trig(indio_dev, indio_dev->trig);
+ if (ret) {
+ dev_err(&indio_dev->dev, "Can't set trigger\n");
+ goto err_unprepare;
+ }
+
+ ret = stm32_adc_dma_start(indio_dev);
+ if (ret) {
+ dev_err(&indio_dev->dev, "Can't start dma\n");
+ goto err_clr_trig;
+ }
+
+ ret = iio_triggered_buffer_postenable(indio_dev);
+ if (ret < 0)
+ goto err_stop_dma;
+
+ /* Reset adc buffer index */
+ adc->bufi = 0;
+
+ if (!adc->dma_chan)
+ stm32_adc_conv_irq_enable(adc);
+
+ adc->cfg->start_conv(adc, !!adc->dma_chan);
+
+ return 0;
+
+err_stop_dma:
+ if (adc->dma_chan)
+ dmaengine_terminate_all(adc->dma_chan);
+err_clr_trig:
+ stm32_adc_set_trig(indio_dev, NULL);
+err_unprepare:
+ if (adc->cfg->unprepare)
+ adc->cfg->unprepare(adc);
+
+ return ret;
+}
+
+static int stm32_adc_buffer_predisable(struct iio_dev *indio_dev)
+{
+ struct stm32_adc *adc = iio_priv(indio_dev);
+ int ret;
+
+ adc->cfg->stop_conv(adc);
+ if (!adc->dma_chan)
+ stm32_adc_conv_irq_disable(adc);
+
+ ret = iio_triggered_buffer_predisable(indio_dev);
+ if (ret < 0)
+ dev_err(&indio_dev->dev, "predisable failed\n");
+
+ if (adc->dma_chan)
+ dmaengine_terminate_all(adc->dma_chan);
+
+ if (stm32_adc_set_trig(indio_dev, NULL))
+ dev_err(&indio_dev->dev, "Can't clear trigger\n");
+
+ if (adc->cfg->unprepare)
+ adc->cfg->unprepare(adc);
+
+ return ret;
+}
+
+static const struct iio_buffer_setup_ops stm32_adc_buffer_setup_ops = {
+ .postenable = &stm32_adc_buffer_postenable,
+ .predisable = &stm32_adc_buffer_predisable,
+};
+
+static irqreturn_t stm32_adc_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct stm32_adc *adc = iio_priv(indio_dev);
+
+ dev_dbg(&indio_dev->dev, "%s bufi=%d\n", __func__, adc->bufi);
+
+ if (!adc->dma_chan) {
+ /* reset buffer index */
+ adc->bufi = 0;
+ iio_push_to_buffers_with_timestamp(indio_dev, adc->buffer,
+ pf->timestamp);
+ } else {
+ int residue = stm32_adc_dma_residue(adc);
+
+ while (residue >= indio_dev->scan_bytes) {
+ u16 *buffer = (u16 *)&adc->rx_buf[adc->bufi];
+
+ iio_push_to_buffers_with_timestamp(indio_dev, buffer,
+ pf->timestamp);
+ residue -= indio_dev->scan_bytes;
+ adc->bufi += indio_dev->scan_bytes;
+ if (adc->bufi >= adc->rx_buf_sz)
+ adc->bufi = 0;
+ }
+ }
+
+ iio_trigger_notify_done(indio_dev->trig);
+
+ /* re-enable eoc irq */
+ if (!adc->dma_chan)
+ stm32_adc_conv_irq_enable(adc);
+
+ return IRQ_HANDLED;
+}
+
+static const struct iio_chan_spec_ext_info stm32_adc_ext_info[] = {
+ IIO_ENUM("trigger_polarity", IIO_SHARED_BY_ALL, &stm32_adc_trig_pol),
+ {
+ .name = "trigger_polarity_available",
+ .shared = IIO_SHARED_BY_ALL,
+ .read = iio_enum_available_read,
+ .private = (uintptr_t)&stm32_adc_trig_pol,
+ },
+ {},
+};
+
+static int stm32_adc_of_get_resolution(struct iio_dev *indio_dev)
+{
+ struct device_node *node = indio_dev->dev.of_node;
+ struct stm32_adc *adc = iio_priv(indio_dev);
+ unsigned int i;
+ u32 res;
+
+ if (of_property_read_u32(node, "assigned-resolution-bits", &res))
+ res = adc->cfg->adc_info->resolutions[0];
+
+ for (i = 0; i < adc->cfg->adc_info->num_res; i++)
+ if (res == adc->cfg->adc_info->resolutions[i])
+ break;
+ if (i >= adc->cfg->adc_info->num_res) {
+ dev_err(&indio_dev->dev, "Bad resolution: %u bits\n", res);
+ return -EINVAL;
+ }
+
+ dev_dbg(&indio_dev->dev, "Using %u bits resolution\n", res);
+ adc->res = i;
+
+ return 0;
+}
+
+static void stm32_adc_smpr_init(struct stm32_adc *adc, int channel, u32 smp_ns)
+{
+ const struct stm32_adc_regs *smpr = &adc->cfg->regs->smp_bits[channel];
+ u32 period_ns, shift = smpr->shift, mask = smpr->mask;
+ unsigned int smp, r = smpr->reg;
+
+ /* Determine sampling time (ADC clock cycles) */
+ period_ns = NSEC_PER_SEC / adc->common->rate;
+ for (smp = 0; smp <= STM32_ADC_MAX_SMP; smp++)
+ if ((period_ns * adc->cfg->smp_cycles[smp]) >= smp_ns)
+ break;
+ if (smp > STM32_ADC_MAX_SMP)
+ smp = STM32_ADC_MAX_SMP;
+
+ /* pre-build sampling time registers (e.g. smpr1, smpr2) */
+ adc->smpr_val[r] = (adc->smpr_val[r] & ~mask) | (smp << shift);
+}
+
+static void stm32_adc_chan_init_one(struct iio_dev *indio_dev,
+ struct iio_chan_spec *chan, u32 vinp,
+ u32 vinn, int scan_index, bool differential)
+{
+ struct stm32_adc *adc = iio_priv(indio_dev);
+ char *name = adc->chan_name[vinp];
+
+ chan->type = IIO_VOLTAGE;
+ chan->channel = vinp;
+ if (differential) {
+ chan->differential = 1;
+ chan->channel2 = vinn;
+ snprintf(name, STM32_ADC_CH_SZ, "in%d-in%d", vinp, vinn);
+ } else {
+ snprintf(name, STM32_ADC_CH_SZ, "in%d", vinp);
+ }
+ chan->datasheet_name = name;
+ chan->scan_index = scan_index;
+ chan->indexed = 1;
+ chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
+ chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_OFFSET);
+ chan->scan_type.sign = 'u';
+ chan->scan_type.realbits = adc->cfg->adc_info->resolutions[adc->res];
+ chan->scan_type.storagebits = 16;
+ chan->ext_info = stm32_adc_ext_info;
+
+ /* pre-build selected channels mask */
+ adc->pcsel |= BIT(chan->channel);
+ if (differential) {
+ /* pre-build diff channels mask */
+ adc->difsel |= BIT(chan->channel);
+ /* Also add negative input to pre-selected channels */
+ adc->pcsel |= BIT(chan->channel2);
+ }
+}
+
+static int stm32_adc_chan_of_init(struct iio_dev *indio_dev)
+{
+ struct device_node *node = indio_dev->dev.of_node;
+ struct stm32_adc *adc = iio_priv(indio_dev);
+ const struct stm32_adc_info *adc_info = adc->cfg->adc_info;
+ struct stm32_adc_diff_channel diff[STM32_ADC_CH_MAX];
+ struct property *prop;
+ const __be32 *cur;
+ struct iio_chan_spec *channels;
+ int scan_index = 0, num_channels = 0, num_diff = 0, ret, i;
+ u32 val, smp = 0;
+
+ ret = of_property_count_u32_elems(node, "st,adc-channels");
+ if (ret > adc_info->max_channels) {
+ dev_err(&indio_dev->dev, "Bad st,adc-channels?\n");
+ return -EINVAL;
+ } else if (ret > 0) {
+ num_channels += ret;
+ }
+
+ ret = of_property_count_elems_of_size(node, "st,adc-diff-channels",
+ sizeof(*diff));
+ if (ret > adc_info->max_channels) {
+ dev_err(&indio_dev->dev, "Bad st,adc-diff-channels?\n");
+ return -EINVAL;
+ } else if (ret > 0) {
+ int size = ret * sizeof(*diff) / sizeof(u32);
+
+ num_diff = ret;
+ num_channels += ret;
+ ret = of_property_read_u32_array(node, "st,adc-diff-channels",
+ (u32 *)diff, size);
+ if (ret)
+ return ret;
+ }
+
+ if (!num_channels) {
+ dev_err(&indio_dev->dev, "No channels configured\n");
+ return -ENODATA;
+ }
+
+ /* Optional sample time is provided either for each, or all channels */
+ ret = of_property_count_u32_elems(node, "st,min-sample-time-nsecs");
+ if (ret > 1 && ret != num_channels) {
+ dev_err(&indio_dev->dev, "Invalid st,min-sample-time-nsecs\n");
+ return -EINVAL;
+ }
+
+ channels = devm_kcalloc(&indio_dev->dev, num_channels,
+ sizeof(struct iio_chan_spec), GFP_KERNEL);
+ if (!channels)
+ return -ENOMEM;
+
+ of_property_for_each_u32(node, "st,adc-channels", prop, cur, val) {
+ if (val >= adc_info->max_channels) {
+ dev_err(&indio_dev->dev, "Invalid channel %d\n", val);
+ return -EINVAL;
+ }
+
+ /* Channel can't be configured both as single-ended & diff */
+ for (i = 0; i < num_diff; i++) {
+ if (val == diff[i].vinp) {
+ dev_err(&indio_dev->dev,
+ "channel %d miss-configured\n", val);
+ return -EINVAL;
+ }
+ }
+ stm32_adc_chan_init_one(indio_dev, &channels[scan_index], val,
+ 0, scan_index, false);
+ scan_index++;
+ }
+
+ for (i = 0; i < num_diff; i++) {
+ if (diff[i].vinp >= adc_info->max_channels ||
+ diff[i].vinn >= adc_info->max_channels) {
+ dev_err(&indio_dev->dev, "Invalid channel in%d-in%d\n",
+ diff[i].vinp, diff[i].vinn);
+ return -EINVAL;
+ }
+ stm32_adc_chan_init_one(indio_dev, &channels[scan_index],
+ diff[i].vinp, diff[i].vinn, scan_index,
+ true);
+ scan_index++;
+ }
+
+ for (i = 0; i < scan_index; i++) {
+ /*
+ * Using of_property_read_u32_index(), smp value will only be
+ * modified if valid u32 value can be decoded. This allows to
+ * get either no value, 1 shared value for all indexes, or one
+ * value per channel.
+ */
+ of_property_read_u32_index(node, "st,min-sample-time-nsecs",
+ i, &smp);
+ /* Prepare sampling time settings */
+ stm32_adc_smpr_init(adc, channels[i].channel, smp);
+ }
+
+ indio_dev->num_channels = scan_index;
+ indio_dev->channels = channels;
+
+ return 0;
+}
+
+static int stm32_adc_dma_request(struct iio_dev *indio_dev)
+{
+ struct stm32_adc *adc = iio_priv(indio_dev);
+ struct dma_slave_config config;
+ int ret;
+
+ adc->dma_chan = dma_request_slave_channel(&indio_dev->dev, "rx");
+ if (!adc->dma_chan)
+ return 0;
+
+ adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev,
+ STM32_DMA_BUFFER_SIZE,
+ &adc->rx_dma_buf, GFP_KERNEL);
+ if (!adc->rx_buf) {
+ ret = -ENOMEM;
+ goto err_release;
+ }
+
+ /* Configure DMA channel to read data register */
+ memset(&config, 0, sizeof(config));
+ config.src_addr = (dma_addr_t)adc->common->phys_base;
+ config.src_addr += adc->offset + adc->cfg->regs->dr;
+ config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+
+ ret = dmaengine_slave_config(adc->dma_chan, &config);
+ if (ret)
+ goto err_free;
+
+ return 0;
+
+err_free:
+ dma_free_coherent(adc->dma_chan->device->dev, STM32_DMA_BUFFER_SIZE,
+ adc->rx_buf, adc->rx_dma_buf);
+err_release:
+ dma_release_channel(adc->dma_chan);
+
+ return ret;
+}
+
+static int stm32_adc_probe(struct platform_device *pdev)
+{
+ struct iio_dev *indio_dev;
+ struct device *dev = &pdev->dev;
+ struct stm32_adc *adc;
+ int ret;
+
+ if (!pdev->dev.of_node)
+ return -ENODEV;
+
+ indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ adc = iio_priv(indio_dev);
+ adc->common = dev_get_drvdata(pdev->dev.parent);
+ spin_lock_init(&adc->lock);
+ init_completion(&adc->completion);
+ adc->cfg = (const struct stm32_adc_cfg *)
+ of_match_device(dev->driver->of_match_table, dev)->data;
+
+ indio_dev->name = dev_name(&pdev->dev);
+ indio_dev->dev.parent = &pdev->dev;
+ indio_dev->dev.of_node = pdev->dev.of_node;
+ indio_dev->info = &stm32_adc_iio_info;
+ indio_dev->modes = INDIO_DIRECT_MODE | INDIO_HARDWARE_TRIGGERED;
+
+ platform_set_drvdata(pdev, adc);
+
+ ret = of_property_read_u32(pdev->dev.of_node, "reg", &adc->offset);
+ if (ret != 0) {
+ dev_err(&pdev->dev, "missing reg property\n");
+ return -EINVAL;
+ }
+
+ adc->irq = platform_get_irq(pdev, 0);
+ if (adc->irq < 0) {
+ dev_err(&pdev->dev, "failed to get irq\n");
+ return adc->irq;
+ }
+
+ ret = devm_request_irq(&pdev->dev, adc->irq, stm32_adc_isr,
+ 0, pdev->name, adc);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to request IRQ\n");
+ return ret;
+ }
+
+ adc->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(adc->clk)) {
+ ret = PTR_ERR(adc->clk);
+ if (ret == -ENOENT && !adc->cfg->clk_required) {
+ adc->clk = NULL;
+ } else {
+ dev_err(&pdev->dev, "Can't get clock\n");
+ return ret;
+ }
+ }
+
+ if (adc->clk) {
+ ret = clk_prepare_enable(adc->clk);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "clk enable failed\n");
+ return ret;
+ }
+ }
+
+ ret = stm32_adc_of_get_resolution(indio_dev);
+ if (ret < 0)
+ goto err_clk_disable;
+ stm32_adc_set_res(adc);
+
+ if (adc->cfg->selfcalib) {
+ ret = adc->cfg->selfcalib(adc);
+ if (ret)
+ goto err_clk_disable;
+ }
+
+ ret = stm32_adc_chan_of_init(indio_dev);
+ if (ret < 0)
+ goto err_clk_disable;
+
+ ret = stm32_adc_dma_request(indio_dev);
+ if (ret < 0)
+ goto err_clk_disable;
+
+ ret = iio_triggered_buffer_setup(indio_dev,
+ &iio_pollfunc_store_time,
+ &stm32_adc_trigger_handler,
+ &stm32_adc_buffer_setup_ops);
+ if (ret) {
+ dev_err(&pdev->dev, "buffer setup failed\n");
+ goto err_dma_disable;
+ }
+
+ ret = iio_device_register(indio_dev);
+ if (ret) {
+ dev_err(&pdev->dev, "iio dev register failed\n");
+ goto err_buffer_cleanup;
+ }
+
+ return 0;
+
+err_buffer_cleanup:
+ iio_triggered_buffer_cleanup(indio_dev);
+
+err_dma_disable:
+ if (adc->dma_chan) {
+ dma_free_coherent(adc->dma_chan->device->dev,
+ STM32_DMA_BUFFER_SIZE,
+ adc->rx_buf, adc->rx_dma_buf);
+ dma_release_channel(adc->dma_chan);
+ }
+err_clk_disable:
+ if (adc->clk)
+ clk_disable_unprepare(adc->clk);
+
+ return ret;
+}
+
+static int stm32_adc_remove(struct platform_device *pdev)
+{
+ struct stm32_adc *adc = platform_get_drvdata(pdev);
+ struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+
+ iio_device_unregister(indio_dev);
+ iio_triggered_buffer_cleanup(indio_dev);
+ if (adc->dma_chan) {
+ dma_free_coherent(adc->dma_chan->device->dev,
+ STM32_DMA_BUFFER_SIZE,
+ adc->rx_buf, adc->rx_dma_buf);
+ dma_release_channel(adc->dma_chan);
+ }
+ if (adc->clk)
+ clk_disable_unprepare(adc->clk);
+
+ return 0;
+}
+
+static const struct stm32_adc_cfg stm32f4_adc_cfg = {
+ .regs = &stm32f4_adc_regspec,
+ .adc_info = &stm32f4_adc_info,
+ .trigs = stm32f4_adc_trigs,
+ .clk_required = true,
+ .start_conv = stm32f4_adc_start_conv,
+ .stop_conv = stm32f4_adc_stop_conv,
+ .smp_cycles = stm32f4_adc_smp_cycles,
+};
+
+static const struct stm32_adc_cfg stm32h7_adc_cfg = {
+ .regs = &stm32h7_adc_regspec,
+ .adc_info = &stm32h7_adc_info,
+ .trigs = stm32h7_adc_trigs,
+ .selfcalib = stm32h7_adc_selfcalib,
+ .start_conv = stm32h7_adc_start_conv,
+ .stop_conv = stm32h7_adc_stop_conv,
+ .prepare = stm32h7_adc_prepare,
+ .unprepare = stm32h7_adc_unprepare,
+ .smp_cycles = stm32h7_adc_smp_cycles,
+};
+
+static const struct stm32_adc_cfg stm32mp1_adc_cfg = {
+ .regs = &stm32h7_adc_regspec,
+ .adc_info = &stm32h7_adc_info,
+ .trigs = stm32h7_adc_trigs,
+ .has_vregready = true,
+ .selfcalib = stm32h7_adc_selfcalib,
+ .start_conv = stm32h7_adc_start_conv,
+ .stop_conv = stm32h7_adc_stop_conv,
+ .prepare = stm32h7_adc_prepare,
+ .unprepare = stm32h7_adc_unprepare,
+ .smp_cycles = stm32h7_adc_smp_cycles,
+};
+
+static const struct of_device_id stm32_adc_of_match[] = {
+ { .compatible = "st,stm32f4-adc", .data = (void *)&stm32f4_adc_cfg },
+ { .compatible = "st,stm32h7-adc", .data = (void *)&stm32h7_adc_cfg },
+ { .compatible = "st,stm32mp1-adc", .data = (void *)&stm32mp1_adc_cfg },
+ {},
+};
+MODULE_DEVICE_TABLE(of, stm32_adc_of_match);
+
+static struct platform_driver stm32_adc_driver = {
+ .probe = stm32_adc_probe,
+ .remove = stm32_adc_remove,
+ .driver = {
+ .name = "stm32-adc",
+ .of_match_table = stm32_adc_of_match,
+ },
+};
+module_platform_driver(stm32_adc_driver);
+
+MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics STM32 ADC IIO driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:stm32-adc");