Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
index 379e8d5..5989b08 100644
--- a/drivers/dma/stm32-dma.c
+++ b/drivers/dma/stm32-dma.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Driver for STM32 DMA controller
*
@@ -6,8 +7,6 @@
* Copyright (C) M'boumba Cedric Madianga 2015
* Author: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
* Pierre-Yves Mordret <pierre-yves.mordret@st.com>
- *
- * License terms: GNU General Public License (GPL), version 2
*/
#include <linux/clk.h>
@@ -23,6 +22,7 @@
#include <linux/of_device.h>
#include <linux/of_dma.h>
#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
#include <linux/reset.h>
#include <linux/sched.h>
#include <linux/slab.h>
@@ -243,12 +243,6 @@
writel_relaxed(val, dmadev->base + reg);
}
-static struct stm32_dma_desc *stm32_dma_alloc_desc(u32 num_sgs)
-{
- return kzalloc(sizeof(struct stm32_dma_desc) +
- sizeof(struct stm32_dma_sg_req) * num_sgs, GFP_NOWAIT);
-}
-
static int stm32_dma_get_width(struct stm32_dma_chan *chan,
enum dma_slave_buswidth width)
{
@@ -308,20 +302,12 @@
static bool stm32_dma_is_burst_possible(u32 buf_len, u32 threshold)
{
- switch (threshold) {
- case STM32_DMA_FIFO_THRESHOLD_FULL:
- if (buf_len >= STM32_DMA_MAX_BURST)
- return true;
- else
- return false;
- case STM32_DMA_FIFO_THRESHOLD_HALFFULL:
- if (buf_len >= STM32_DMA_MAX_BURST / 2)
- return true;
- else
- return false;
- default:
- return false;
- }
+ /*
+ * Buffer or period length has to be aligned on FIFO depth.
+ * Otherwise bytes may be stuck within FIFO at buffer or period
+ * length.
+ */
+ return ((buf_len % ((threshold + 1) * 4)) == 0);
}
static u32 stm32_dma_get_best_burst(u32 buf_len, u32 max_burst, u32 threshold,
@@ -649,12 +635,13 @@
{
struct stm32_dma_chan *chan = devid;
struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
- u32 status, scr;
+ u32 status, scr, sfcr;
spin_lock(&chan->vchan.lock);
status = stm32_dma_irq_status(chan);
scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
+ sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
if (status & STM32_DMA_TCI) {
stm32_dma_irq_clear(chan, STM32_DMA_TCI);
@@ -669,10 +656,12 @@
if (status & STM32_DMA_FEI) {
stm32_dma_irq_clear(chan, STM32_DMA_FEI);
status &= ~STM32_DMA_FEI;
- if (!(scr & STM32_DMA_SCR_EN))
- dev_err(chan2dev(chan), "FIFO Error\n");
- else
- dev_dbg(chan2dev(chan), "FIFO over/underrun\n");
+ if (sfcr & STM32_DMA_SFCR_FEIE) {
+ if (!(scr & STM32_DMA_SCR_EN))
+ dev_err(chan2dev(chan), "FIFO Error\n");
+ else
+ dev_dbg(chan2dev(chan), "FIFO over/underrun\n");
+ }
}
if (status) {
stm32_dma_irq_clear(chan, status);
@@ -858,7 +847,7 @@
return NULL;
}
- desc = stm32_dma_alloc_desc(sg_len);
+ desc = kzalloc(struct_size(desc, sg_req, sg_len), GFP_NOWAIT);
if (!desc)
return NULL;
@@ -959,7 +948,7 @@
num_periods = buf_len / period_len;
- desc = stm32_dma_alloc_desc(num_periods);
+ desc = kzalloc(struct_size(desc, sg_req, num_periods), GFP_NOWAIT);
if (!desc)
return NULL;
@@ -994,7 +983,7 @@
int i;
num_sgs = DIV_ROUND_UP(len, STM32_DMA_ALIGNED_MAX_DATA_ITEMS);
- desc = stm32_dma_alloc_desc(num_sgs);
+ desc = kzalloc(struct_size(desc, sg_req, num_sgs), GFP_NOWAIT);
if (!desc)
return NULL;
@@ -1046,33 +1035,97 @@
return ndtr << width;
}
+/**
+ * stm32_dma_is_current_sg - check that expected sg_req is currently transferred
+ * @chan: dma channel
+ *
+ * This function called when IRQ are disable, checks that the hardware has not
+ * switched on the next transfer in double buffer mode. The test is done by
+ * comparing the next_sg memory address with the hardware related register
+ * (based on CT bit value).
+ *
+ * Returns true if expected current transfer is still running or double
+ * buffer mode is not activated.
+ */
+static bool stm32_dma_is_current_sg(struct stm32_dma_chan *chan)
+{
+ struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
+ struct stm32_dma_sg_req *sg_req;
+ u32 dma_scr, dma_smar, id;
+
+ id = chan->id;
+ dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
+
+ if (!(dma_scr & STM32_DMA_SCR_DBM))
+ return true;
+
+ sg_req = &chan->desc->sg_req[chan->next_sg];
+
+ if (dma_scr & STM32_DMA_SCR_CT) {
+ dma_smar = stm32_dma_read(dmadev, STM32_DMA_SM0AR(id));
+ return (dma_smar == sg_req->chan_reg.dma_sm0ar);
+ }
+
+ dma_smar = stm32_dma_read(dmadev, STM32_DMA_SM1AR(id));
+
+ return (dma_smar == sg_req->chan_reg.dma_sm1ar);
+}
+
static size_t stm32_dma_desc_residue(struct stm32_dma_chan *chan,
struct stm32_dma_desc *desc,
u32 next_sg)
{
u32 modulo, burst_size;
- u32 residue = 0;
+ u32 residue;
+ u32 n_sg = next_sg;
+ struct stm32_dma_sg_req *sg_req = &chan->desc->sg_req[chan->next_sg];
int i;
/*
- * In cyclic mode, for the last period, residue = remaining bytes from
- * NDTR
+ * Calculate the residue means compute the descriptors
+ * information:
+ * - the sg_req currently transferred
+ * - the Hardware remaining position in this sg (NDTR bits field).
+ *
+ * A race condition may occur if DMA is running in cyclic or double
+ * buffer mode, since the DMA register are automatically reloaded at end
+ * of period transfer. The hardware may have switched to the next
+ * transfer (CT bit updated) just before the position (SxNDTR reg) is
+ * read.
+ * In this case the SxNDTR reg could (or not) correspond to the new
+ * transfer position, and not the expected one.
+ * The strategy implemented in the stm32 driver is to:
+ * - read the SxNDTR register
+ * - crosscheck that hardware is still in current transfer.
+ * In case of switch, we can assume that the DMA is at the beginning of
+ * the next transfer. So we approximate the residue in consequence, by
+ * pointing on the beginning of next transfer.
+ *
+ * This race condition doesn't apply for none cyclic mode, as double
+ * buffer is not used. In such situation registers are updated by the
+ * software.
*/
- if (chan->desc->cyclic && next_sg == 0) {
- residue = stm32_dma_get_remaining_bytes(chan);
- goto end;
+
+ residue = stm32_dma_get_remaining_bytes(chan);
+
+ if (!stm32_dma_is_current_sg(chan)) {
+ n_sg++;
+ if (n_sg == chan->desc->num_sgs)
+ n_sg = 0;
+ residue = sg_req->len;
}
/*
- * For all other periods in cyclic mode, and in sg mode,
- * residue = remaining bytes from NDTR + remaining periods/sg to be
- * transferred
+ * In cyclic mode, for the last period, residue = remaining bytes
+ * from NDTR,
+ * else for all other periods in cyclic mode, and in sg mode,
+ * residue = remaining bytes from NDTR + remaining
+ * periods/sg to be transferred
*/
- for (i = next_sg; i < desc->num_sgs; i++)
- residue += desc->sg_req[i].len;
- residue += stm32_dma_get_remaining_bytes(chan);
+ if (!chan->desc->cyclic || n_sg != 0)
+ for (i = n_sg; i < desc->num_sgs; i++)
+ residue += desc->sg_req[i].len;
-end:
if (!chan->mem_burst)
return residue;
@@ -1120,15 +1173,14 @@
int ret;
chan->config_init = false;
- ret = clk_prepare_enable(dmadev->clk);
- if (ret < 0) {
- dev_err(chan2dev(chan), "clk_prepare_enable failed: %d\n", ret);
+
+ ret = pm_runtime_get_sync(dmadev->ddev.dev);
+ if (ret < 0)
return ret;
- }
ret = stm32_dma_disable_chan(chan);
if (ret < 0)
- clk_disable_unprepare(dmadev->clk);
+ pm_runtime_put(dmadev->ddev.dev);
return ret;
}
@@ -1148,7 +1200,7 @@
spin_unlock_irqrestore(&chan->vchan.lock, flags);
}
- clk_disable_unprepare(dmadev->clk);
+ pm_runtime_put(dmadev->ddev.dev);
vchan_free_chan_resources(to_virt_chan(c));
}
@@ -1248,6 +1300,12 @@
return PTR_ERR(dmadev->clk);
}
+ ret = clk_prepare_enable(dmadev->clk);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "clk_prep_enable error: %d\n", ret);
+ return ret;
+ }
+
dmadev->mem2mem = of_property_read_bool(pdev->dev.of_node,
"st,mem2mem");
@@ -1297,17 +1355,15 @@
ret = dma_async_device_register(dd);
if (ret)
- return ret;
+ goto clk_free;
for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
chan = &dmadev->chan[i];
- res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
- if (!res) {
- ret = -EINVAL;
- dev_err(&pdev->dev, "No irq resource for chan %d\n", i);
+ ret = platform_get_irq(pdev, i);
+ if (ret < 0)
goto err_unregister;
- }
- chan->irq = res->start;
+ chan->irq = ret;
+
ret = devm_request_irq(&pdev->dev, chan->irq,
stm32_dma_chan_irq, 0,
dev_name(chan2dev(chan)), chan);
@@ -1329,20 +1385,58 @@
platform_set_drvdata(pdev, dmadev);
+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+ pm_runtime_get_noresume(&pdev->dev);
+ pm_runtime_put(&pdev->dev);
+
dev_info(&pdev->dev, "STM32 DMA driver registered\n");
return 0;
err_unregister:
dma_async_device_unregister(dd);
+clk_free:
+ clk_disable_unprepare(dmadev->clk);
return ret;
}
+#ifdef CONFIG_PM
+static int stm32_dma_runtime_suspend(struct device *dev)
+{
+ struct stm32_dma_device *dmadev = dev_get_drvdata(dev);
+
+ clk_disable_unprepare(dmadev->clk);
+
+ return 0;
+}
+
+static int stm32_dma_runtime_resume(struct device *dev)
+{
+ struct stm32_dma_device *dmadev = dev_get_drvdata(dev);
+ int ret;
+
+ ret = clk_prepare_enable(dmadev->clk);
+ if (ret) {
+ dev_err(dev, "failed to prepare_enable clock\n");
+ return ret;
+ }
+
+ return 0;
+}
+#endif
+
+static const struct dev_pm_ops stm32_dma_pm_ops = {
+ SET_RUNTIME_PM_OPS(stm32_dma_runtime_suspend,
+ stm32_dma_runtime_resume, NULL)
+};
+
static struct platform_driver stm32_dma_driver = {
.driver = {
.name = "stm32-dma",
.of_match_table = stm32_dma_of_match,
+ .pm = &stm32_dma_pm_ops,
},
};