Update Linux to v5.10.109
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz
Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/drivers/clocksource/timer-microchip-pit64b.c b/drivers/clocksource/timer-microchip-pit64b.c
new file mode 100644
index 0000000..59e11ca
--- /dev/null
+++ b/drivers/clocksource/timer-microchip-pit64b.c
@@ -0,0 +1,452 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 64-bit Periodic Interval Timer driver
+ *
+ * Copyright (C) 2019 Microchip Technology Inc. and its subsidiaries
+ *
+ * Author: Claudiu Beznea <claudiu.beznea@microchip.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/sched_clock.h>
+#include <linux/slab.h>
+
+#define MCHP_PIT64B_CR 0x00 /* Control Register */
+#define MCHP_PIT64B_CR_START BIT(0)
+#define MCHP_PIT64B_CR_SWRST BIT(8)
+
+#define MCHP_PIT64B_MR 0x04 /* Mode Register */
+#define MCHP_PIT64B_MR_CONT BIT(0)
+#define MCHP_PIT64B_MR_ONE_SHOT (0)
+#define MCHP_PIT64B_MR_SGCLK BIT(3)
+#define MCHP_PIT64B_MR_PRES GENMASK(11, 8)
+
+#define MCHP_PIT64B_LSB_PR 0x08 /* LSB Period Register */
+
+#define MCHP_PIT64B_MSB_PR 0x0C /* MSB Period Register */
+
+#define MCHP_PIT64B_IER 0x10 /* Interrupt Enable Register */
+#define MCHP_PIT64B_IER_PERIOD BIT(0)
+
+#define MCHP_PIT64B_ISR 0x1C /* Interrupt Status Register */
+
+#define MCHP_PIT64B_TLSBR 0x20 /* Timer LSB Register */
+
+#define MCHP_PIT64B_TMSBR 0x24 /* Timer MSB Register */
+
+#define MCHP_PIT64B_PRES_MAX 0x10
+#define MCHP_PIT64B_LSBMASK GENMASK_ULL(31, 0)
+#define MCHP_PIT64B_PRES_TO_MODE(p) (MCHP_PIT64B_MR_PRES & ((p) << 8))
+#define MCHP_PIT64B_MODE_TO_PRES(m) ((MCHP_PIT64B_MR_PRES & (m)) >> 8)
+#define MCHP_PIT64B_DEF_CS_FREQ 5000000UL /* 5 MHz */
+#define MCHP_PIT64B_DEF_CE_FREQ 32768 /* 32 KHz */
+
+#define MCHP_PIT64B_NAME "pit64b"
+
+/**
+ * struct mchp_pit64b_timer - PIT64B timer data structure
+ * @base: base address of PIT64B hardware block
+ * @pclk: PIT64B's peripheral clock
+ * @gclk: PIT64B's generic clock
+ * @mode: precomputed value for mode register
+ */
+struct mchp_pit64b_timer {
+ void __iomem *base;
+ struct clk *pclk;
+ struct clk *gclk;
+ u32 mode;
+};
+
+/**
+ * mchp_pit64b_clkevt - PIT64B clockevent data structure
+ * @timer: PIT64B timer
+ * @clkevt: clockevent
+ */
+struct mchp_pit64b_clkevt {
+ struct mchp_pit64b_timer timer;
+ struct clock_event_device clkevt;
+};
+
+#define to_mchp_pit64b_timer(x) \
+ ((struct mchp_pit64b_timer *)container_of(x,\
+ struct mchp_pit64b_clkevt, clkevt))
+
+/* Base address for clocksource timer. */
+static void __iomem *mchp_pit64b_cs_base;
+/* Default cycles for clockevent timer. */
+static u64 mchp_pit64b_ce_cycles;
+
+static inline u64 mchp_pit64b_cnt_read(void __iomem *base)
+{
+ unsigned long flags;
+ u32 low, high;
+
+ raw_local_irq_save(flags);
+
+ /*
+ * When using a 64 bit period TLSB must be read first, followed by the
+ * read of TMSB. This sequence generates an atomic read of the 64 bit
+ * timer value whatever the lapse of time between the accesses.
+ */
+ low = readl_relaxed(base + MCHP_PIT64B_TLSBR);
+ high = readl_relaxed(base + MCHP_PIT64B_TMSBR);
+
+ raw_local_irq_restore(flags);
+
+ return (((u64)high << 32) | low);
+}
+
+static inline void mchp_pit64b_reset(struct mchp_pit64b_timer *timer,
+ u64 cycles, u32 mode, u32 irqs)
+{
+ u32 low, high;
+
+ low = cycles & MCHP_PIT64B_LSBMASK;
+ high = cycles >> 32;
+
+ writel_relaxed(MCHP_PIT64B_CR_SWRST, timer->base + MCHP_PIT64B_CR);
+ writel_relaxed(mode | timer->mode, timer->base + MCHP_PIT64B_MR);
+ writel_relaxed(high, timer->base + MCHP_PIT64B_MSB_PR);
+ writel_relaxed(low, timer->base + MCHP_PIT64B_LSB_PR);
+ writel_relaxed(irqs, timer->base + MCHP_PIT64B_IER);
+ writel_relaxed(MCHP_PIT64B_CR_START, timer->base + MCHP_PIT64B_CR);
+}
+
+static u64 mchp_pit64b_clksrc_read(struct clocksource *cs)
+{
+ return mchp_pit64b_cnt_read(mchp_pit64b_cs_base);
+}
+
+static u64 mchp_pit64b_sched_read_clk(void)
+{
+ return mchp_pit64b_cnt_read(mchp_pit64b_cs_base);
+}
+
+static int mchp_pit64b_clkevt_shutdown(struct clock_event_device *cedev)
+{
+ struct mchp_pit64b_timer *timer = to_mchp_pit64b_timer(cedev);
+
+ writel_relaxed(MCHP_PIT64B_CR_SWRST, timer->base + MCHP_PIT64B_CR);
+
+ return 0;
+}
+
+static int mchp_pit64b_clkevt_set_periodic(struct clock_event_device *cedev)
+{
+ struct mchp_pit64b_timer *timer = to_mchp_pit64b_timer(cedev);
+
+ mchp_pit64b_reset(timer, mchp_pit64b_ce_cycles, MCHP_PIT64B_MR_CONT,
+ MCHP_PIT64B_IER_PERIOD);
+
+ return 0;
+}
+
+static int mchp_pit64b_clkevt_set_next_event(unsigned long evt,
+ struct clock_event_device *cedev)
+{
+ struct mchp_pit64b_timer *timer = to_mchp_pit64b_timer(cedev);
+
+ mchp_pit64b_reset(timer, evt, MCHP_PIT64B_MR_ONE_SHOT,
+ MCHP_PIT64B_IER_PERIOD);
+
+ return 0;
+}
+
+static void mchp_pit64b_clkevt_suspend(struct clock_event_device *cedev)
+{
+ struct mchp_pit64b_timer *timer = to_mchp_pit64b_timer(cedev);
+
+ writel_relaxed(MCHP_PIT64B_CR_SWRST, timer->base + MCHP_PIT64B_CR);
+ if (timer->mode & MCHP_PIT64B_MR_SGCLK)
+ clk_disable_unprepare(timer->gclk);
+ clk_disable_unprepare(timer->pclk);
+}
+
+static void mchp_pit64b_clkevt_resume(struct clock_event_device *cedev)
+{
+ struct mchp_pit64b_timer *timer = to_mchp_pit64b_timer(cedev);
+
+ clk_prepare_enable(timer->pclk);
+ if (timer->mode & MCHP_PIT64B_MR_SGCLK)
+ clk_prepare_enable(timer->gclk);
+}
+
+static irqreturn_t mchp_pit64b_interrupt(int irq, void *dev_id)
+{
+ struct mchp_pit64b_clkevt *irq_data = dev_id;
+
+ /* Need to clear the interrupt. */
+ readl_relaxed(irq_data->timer.base + MCHP_PIT64B_ISR);
+
+ irq_data->clkevt.event_handler(&irq_data->clkevt);
+
+ return IRQ_HANDLED;
+}
+
+static void __init mchp_pit64b_pres_compute(u32 *pres, u32 clk_rate,
+ u32 max_rate)
+{
+ u32 tmp;
+
+ for (*pres = 0; *pres < MCHP_PIT64B_PRES_MAX; (*pres)++) {
+ tmp = clk_rate / (*pres + 1);
+ if (tmp <= max_rate)
+ break;
+ }
+
+ /* Use the bigest prescaler if we didn't match one. */
+ if (*pres == MCHP_PIT64B_PRES_MAX)
+ *pres = MCHP_PIT64B_PRES_MAX - 1;
+}
+
+/**
+ * mchp_pit64b_init_mode - prepare PIT64B mode register value to be used at
+ * runtime; this includes prescaler and SGCLK bit
+ *
+ * PIT64B timer may be fed by gclk or pclk. When gclk is used its rate has to
+ * be at least 3 times lower that pclk's rate. pclk rate is fixed, gclk rate
+ * could be changed via clock APIs. The chosen clock (pclk or gclk) could be
+ * divided by the internal PIT64B's divider.
+ *
+ * This function, first tries to use GCLK by requesting the desired rate from
+ * PMC and then using the internal PIT64B prescaler, if any, to reach the
+ * requested rate. If PCLK/GCLK < 3 (condition requested by PIT64B hardware)
+ * then the function falls back on using PCLK as clock source for PIT64B timer
+ * choosing the highest prescaler in case it doesn't locate one to match the
+ * requested frequency.
+ *
+ * Below is presented the PIT64B block in relation with PMC:
+ *
+ * PIT64B
+ * PMC +------------------------------------+
+ * +----+ | +-----+ |
+ * | |-->gclk -->|-->| | +---------+ +-----+ |
+ * | | | | MUX |--->| Divider |->|timer| |
+ * | |-->pclk -->|-->| | +---------+ +-----+ |
+ * +----+ | +-----+ |
+ * | ^ |
+ * | sel |
+ * +------------------------------------+
+ *
+ * Where:
+ * - gclk rate <= pclk rate/3
+ * - gclk rate could be requested from PMC
+ * - pclk rate is fixed (cannot be requested from PMC)
+ */
+static int __init mchp_pit64b_init_mode(struct mchp_pit64b_timer *timer,
+ unsigned long max_rate)
+{
+ unsigned long pclk_rate, diff = 0, best_diff = ULONG_MAX;
+ long gclk_round = 0;
+ u32 pres, best_pres = 0;
+
+ pclk_rate = clk_get_rate(timer->pclk);
+ if (!pclk_rate)
+ return -EINVAL;
+
+ timer->mode = 0;
+
+ /* Try using GCLK. */
+ gclk_round = clk_round_rate(timer->gclk, max_rate);
+ if (gclk_round < 0)
+ goto pclk;
+
+ if (pclk_rate / gclk_round < 3)
+ goto pclk;
+
+ mchp_pit64b_pres_compute(&pres, gclk_round, max_rate);
+ best_diff = abs(gclk_round / (pres + 1) - max_rate);
+ best_pres = pres;
+
+ if (!best_diff) {
+ timer->mode |= MCHP_PIT64B_MR_SGCLK;
+ clk_set_rate(timer->gclk, gclk_round);
+ goto done;
+ }
+
+pclk:
+ /* Check if requested rate could be obtained using PCLK. */
+ mchp_pit64b_pres_compute(&pres, pclk_rate, max_rate);
+ diff = abs(pclk_rate / (pres + 1) - max_rate);
+
+ if (best_diff > diff) {
+ /* Use PCLK. */
+ best_pres = pres;
+ } else {
+ /* Use GCLK. */
+ timer->mode |= MCHP_PIT64B_MR_SGCLK;
+ clk_set_rate(timer->gclk, gclk_round);
+ }
+
+done:
+ timer->mode |= MCHP_PIT64B_PRES_TO_MODE(best_pres);
+
+ pr_info("PIT64B: using clk=%s with prescaler %u, freq=%lu [Hz]\n",
+ timer->mode & MCHP_PIT64B_MR_SGCLK ? "gclk" : "pclk", best_pres,
+ timer->mode & MCHP_PIT64B_MR_SGCLK ?
+ gclk_round / (best_pres + 1) : pclk_rate / (best_pres + 1));
+
+ return 0;
+}
+
+static int __init mchp_pit64b_init_clksrc(struct mchp_pit64b_timer *timer,
+ u32 clk_rate)
+{
+ int ret;
+
+ mchp_pit64b_reset(timer, ULLONG_MAX, MCHP_PIT64B_MR_CONT, 0);
+
+ mchp_pit64b_cs_base = timer->base;
+
+ ret = clocksource_mmio_init(timer->base, MCHP_PIT64B_NAME, clk_rate,
+ 210, 64, mchp_pit64b_clksrc_read);
+ if (ret) {
+ pr_debug("clksrc: Failed to register PIT64B clocksource!\n");
+
+ /* Stop timer. */
+ writel_relaxed(MCHP_PIT64B_CR_SWRST,
+ timer->base + MCHP_PIT64B_CR);
+
+ return ret;
+ }
+
+ sched_clock_register(mchp_pit64b_sched_read_clk, 64, clk_rate);
+
+ return 0;
+}
+
+static int __init mchp_pit64b_init_clkevt(struct mchp_pit64b_timer *timer,
+ u32 clk_rate, u32 irq)
+{
+ struct mchp_pit64b_clkevt *ce;
+ int ret;
+
+ ce = kzalloc(sizeof(*ce), GFP_KERNEL);
+ if (!ce)
+ return -ENOMEM;
+
+ mchp_pit64b_ce_cycles = DIV_ROUND_CLOSEST(clk_rate, HZ);
+
+ ce->timer.base = timer->base;
+ ce->timer.pclk = timer->pclk;
+ ce->timer.gclk = timer->gclk;
+ ce->timer.mode = timer->mode;
+ ce->clkevt.name = MCHP_PIT64B_NAME;
+ ce->clkevt.features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC;
+ ce->clkevt.rating = 150;
+ ce->clkevt.set_state_shutdown = mchp_pit64b_clkevt_shutdown;
+ ce->clkevt.set_state_periodic = mchp_pit64b_clkevt_set_periodic;
+ ce->clkevt.set_next_event = mchp_pit64b_clkevt_set_next_event;
+ ce->clkevt.suspend = mchp_pit64b_clkevt_suspend;
+ ce->clkevt.resume = mchp_pit64b_clkevt_resume;
+ ce->clkevt.cpumask = cpumask_of(0);
+ ce->clkevt.irq = irq;
+
+ ret = request_irq(irq, mchp_pit64b_interrupt, IRQF_TIMER,
+ "pit64b_tick", ce);
+ if (ret) {
+ pr_debug("clkevt: Failed to setup PIT64B IRQ\n");
+ kfree(ce);
+ return ret;
+ }
+
+ clockevents_config_and_register(&ce->clkevt, clk_rate, 1, ULONG_MAX);
+
+ return 0;
+}
+
+static int __init mchp_pit64b_dt_init_timer(struct device_node *node,
+ bool clkevt)
+{
+ u32 freq = clkevt ? MCHP_PIT64B_DEF_CE_FREQ : MCHP_PIT64B_DEF_CS_FREQ;
+ struct mchp_pit64b_timer timer;
+ unsigned long clk_rate;
+ u32 irq = 0;
+ int ret;
+
+ /* Parse DT node. */
+ timer.pclk = of_clk_get_by_name(node, "pclk");
+ if (IS_ERR(timer.pclk))
+ return PTR_ERR(timer.pclk);
+
+ timer.gclk = of_clk_get_by_name(node, "gclk");
+ if (IS_ERR(timer.gclk))
+ return PTR_ERR(timer.gclk);
+
+ timer.base = of_iomap(node, 0);
+ if (!timer.base)
+ return -ENXIO;
+
+ if (clkevt) {
+ irq = irq_of_parse_and_map(node, 0);
+ if (!irq) {
+ ret = -ENODEV;
+ goto io_unmap;
+ }
+ }
+
+ /* Initialize mode (prescaler + SGCK bit). To be used at runtime. */
+ ret = mchp_pit64b_init_mode(&timer, freq);
+ if (ret)
+ goto irq_unmap;
+
+ ret = clk_prepare_enable(timer.pclk);
+ if (ret)
+ goto irq_unmap;
+
+ if (timer.mode & MCHP_PIT64B_MR_SGCLK) {
+ ret = clk_prepare_enable(timer.gclk);
+ if (ret)
+ goto pclk_unprepare;
+
+ clk_rate = clk_get_rate(timer.gclk);
+ } else {
+ clk_rate = clk_get_rate(timer.pclk);
+ }
+ clk_rate = clk_rate / (MCHP_PIT64B_MODE_TO_PRES(timer.mode) + 1);
+
+ if (clkevt)
+ ret = mchp_pit64b_init_clkevt(&timer, clk_rate, irq);
+ else
+ ret = mchp_pit64b_init_clksrc(&timer, clk_rate);
+
+ if (ret)
+ goto gclk_unprepare;
+
+ return 0;
+
+gclk_unprepare:
+ if (timer.mode & MCHP_PIT64B_MR_SGCLK)
+ clk_disable_unprepare(timer.gclk);
+pclk_unprepare:
+ clk_disable_unprepare(timer.pclk);
+irq_unmap:
+ irq_dispose_mapping(irq);
+io_unmap:
+ iounmap(timer.base);
+
+ return ret;
+}
+
+static int __init mchp_pit64b_dt_init(struct device_node *node)
+{
+ static int inits;
+
+ switch (inits++) {
+ case 0:
+ /* 1st request, register clockevent. */
+ return mchp_pit64b_dt_init_timer(node, true);
+ case 1:
+ /* 2nd request, register clocksource. */
+ return mchp_pit64b_dt_init_timer(node, false);
+ }
+
+ /* The rest, don't care. */
+ return -EINVAL;
+}
+
+TIMER_OF_DECLARE(mchp_pit64b, "microchip,sam9x60-pit64b", mchp_pit64b_dt_init);