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path: root/drivers/i2c/busses/i2c-stm32f7.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-stm32f7.c')
-rw-r--r--drivers/i2c/busses/i2c-stm32f7.c89
1 files changed, 60 insertions, 29 deletions
diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
index 0d3c9a041b56..983509936727 100644
--- a/drivers/i2c/busses/i2c-stm32f7.c
+++ b/drivers/i2c/busses/i2c-stm32f7.c
@@ -325,6 +325,7 @@ struct stm32f7_i2c_alert {
* @dnf_dt: value of digital filter requested via dt
* @dnf: value of digital filter to apply
* @alert: SMBus alert specific data
+ * @atomic: boolean indicating that current transfer is atomic
*/
struct stm32f7_i2c_dev {
struct i2c_adapter adap;
@@ -357,6 +358,7 @@ struct stm32f7_i2c_dev {
u32 dnf_dt;
u32 dnf;
struct stm32f7_i2c_alert *alert;
+ bool atomic;
};
/*
@@ -915,7 +917,8 @@ static void stm32f7_i2c_xfer_msg(struct stm32f7_i2c_dev *i2c_dev,
/* Configure DMA or enable RX/TX interrupt */
i2c_dev->use_dma = false;
- if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN) {
+ if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN
+ && !i2c_dev->atomic) {
ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma,
msg->flags & I2C_M_RD,
f7_msg->count, f7_msg->buf,
@@ -939,6 +942,9 @@ static void stm32f7_i2c_xfer_msg(struct stm32f7_i2c_dev *i2c_dev,
cr1 |= STM32F7_I2C_CR1_TXDMAEN;
}
+ if (i2c_dev->atomic)
+ cr1 &= ~STM32F7_I2C_ALL_IRQ_MASK; /* Disable all interrupts */
+
/* Configure Start/Repeated Start */
cr2 |= STM32F7_I2C_CR2_START;
@@ -1673,7 +1679,22 @@ static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data)
return IRQ_HANDLED;
}
-static int stm32f7_i2c_xfer(struct i2c_adapter *i2c_adap,
+static int stm32f7_i2c_wait_polling(struct stm32f7_i2c_dev *i2c_dev)
+{
+ ktime_t timeout = ktime_add_ms(ktime_get(), i2c_dev->adap.timeout);
+
+ while (ktime_compare(ktime_get(), timeout) < 0) {
+ udelay(5);
+ stm32f7_i2c_isr_event(0, i2c_dev);
+
+ if (completion_done(&i2c_dev->complete))
+ return 1;
+ }
+
+ return 0;
+}
+
+static int stm32f7_i2c_xfer_core(struct i2c_adapter *i2c_adap,
struct i2c_msg msgs[], int num)
{
struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap);
@@ -1697,8 +1718,12 @@ static int stm32f7_i2c_xfer(struct i2c_adapter *i2c_adap,
stm32f7_i2c_xfer_msg(i2c_dev, msgs);
- time_left = wait_for_completion_timeout(&i2c_dev->complete,
- i2c_dev->adap.timeout);
+ if (!i2c_dev->atomic)
+ time_left = wait_for_completion_timeout(&i2c_dev->complete,
+ i2c_dev->adap.timeout);
+ else
+ time_left = stm32f7_i2c_wait_polling(i2c_dev);
+
ret = f7_msg->result;
if (ret) {
if (i2c_dev->use_dma)
@@ -1730,6 +1755,24 @@ pm_free:
return (ret < 0) ? ret : num;
}
+static int stm32f7_i2c_xfer(struct i2c_adapter *i2c_adap,
+ struct i2c_msg msgs[], int num)
+{
+ struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap);
+
+ i2c_dev->atomic = false;
+ return stm32f7_i2c_xfer_core(i2c_adap, msgs, num);
+}
+
+static int stm32f7_i2c_xfer_atomic(struct i2c_adapter *i2c_adap,
+ struct i2c_msg msgs[], int num)
+{
+ struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap);
+
+ i2c_dev->atomic = true;
+ return stm32f7_i2c_xfer_core(i2c_adap, msgs, num);
+}
+
static int stm32f7_i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
unsigned short flags, char read_write,
u8 command, int size,
@@ -2098,6 +2141,7 @@ static u32 stm32f7_i2c_func(struct i2c_adapter *adap)
static const struct i2c_algorithm stm32f7_i2c_algo = {
.master_xfer = stm32f7_i2c_xfer,
+ .master_xfer_atomic = stm32f7_i2c_xfer_atomic,
.smbus_xfer = stm32f7_i2c_smbus_xfer,
.functionality = stm32f7_i2c_func,
.reg_slave = stm32f7_i2c_reg_slave,
@@ -2134,23 +2178,16 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
i2c_dev->wakeup_src = of_property_read_bool(pdev->dev.of_node,
"wakeup-source");
- i2c_dev->clk = devm_clk_get(&pdev->dev, NULL);
+ i2c_dev->clk = devm_clk_get_enabled(&pdev->dev, NULL);
if (IS_ERR(i2c_dev->clk))
return dev_err_probe(&pdev->dev, PTR_ERR(i2c_dev->clk),
- "Failed to get controller clock\n");
-
- ret = clk_prepare_enable(i2c_dev->clk);
- if (ret) {
- dev_err(&pdev->dev, "Failed to prepare_enable clock\n");
- return ret;
- }
+ "Failed to enable controller clock\n");
rst = devm_reset_control_get(&pdev->dev, NULL);
- if (IS_ERR(rst)) {
- ret = dev_err_probe(&pdev->dev, PTR_ERR(rst),
- "Error: Missing reset ctrl\n");
- goto clk_free;
- }
+ if (IS_ERR(rst))
+ return dev_err_probe(&pdev->dev, PTR_ERR(rst),
+ "Error: Missing reset ctrl\n");
+
reset_control_assert(rst);
udelay(2);
reset_control_deassert(rst);
@@ -2165,7 +2202,7 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
if (ret) {
dev_err(&pdev->dev, "Failed to request irq event %i\n",
irq_event);
- goto clk_free;
+ return ret;
}
ret = devm_request_irq(&pdev->dev, irq_error, stm32f7_i2c_isr_error, 0,
@@ -2173,29 +2210,28 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
if (ret) {
dev_err(&pdev->dev, "Failed to request irq error %i\n",
irq_error);
- goto clk_free;
+ return ret;
}
setup = of_device_get_match_data(&pdev->dev);
if (!setup) {
dev_err(&pdev->dev, "Can't get device data\n");
- ret = -ENODEV;
- goto clk_free;
+ return -ENODEV;
}
i2c_dev->setup = *setup;
ret = stm32f7_i2c_setup_timing(i2c_dev, &i2c_dev->setup);
if (ret)
- goto clk_free;
+ return ret;
/* Setup Fast mode plus if necessary */
if (i2c_dev->bus_rate > I2C_MAX_FAST_MODE_FREQ) {
ret = stm32f7_i2c_setup_fm_plus_bits(pdev, i2c_dev);
if (ret)
- goto clk_free;
+ return ret;
ret = stm32f7_i2c_write_fm_plus_bits(i2c_dev, true);
if (ret)
- goto clk_free;
+ return ret;
}
adap = &i2c_dev->adap;
@@ -2306,9 +2342,6 @@ clr_wakeup_capable:
fmp_clear:
stm32f7_i2c_write_fm_plus_bits(i2c_dev, false);
-clk_free:
- clk_disable_unprepare(i2c_dev->clk);
-
return ret;
}
@@ -2342,8 +2375,6 @@ static void stm32f7_i2c_remove(struct platform_device *pdev)
}
stm32f7_i2c_write_fm_plus_bits(i2c_dev, false);
-
- clk_disable_unprepare(i2c_dev->clk);
}
static int __maybe_unused stm32f7_i2c_runtime_suspend(struct device *dev)