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Message-ID: <1579795970-22319-2-git-send-email-alain.volmat@st.com>
Date: Thu, 23 Jan 2020 17:12:46 +0100
From: Alain Volmat <alain.volmat@...com>
To: <wsa@...-dreams.de>, <robh+dt@...nel.org>
CC: <mark.rutland@....com>, <pierre-yves.mordret@...com>,
<mcoquelin.stm32@...il.com>, <alexandre.torgue@...com>,
<linux-i2c@...r.kernel.org>, <devicetree@...r.kernel.org>,
<linux-stm32@...md-mailman.stormreply.com>,
<linux-arm-kernel@...ts.infradead.org>,
<linux-kernel@...r.kernel.org>, <fabrice.gasnier@...com>,
<alain.volmat@...com>
Subject: [PATCH 1/5] i2c: i2c-stm32f7: disable/restore Fast Mode Plus bits in low power modes
Defer the initial enabling of the Fast Mode Plus bits after the
stm32f7_i2c_setup_timing call in probe function in order to avoid
enabling them if speed is downgraded.
Clear & restore the Fast Mode Plus bits in the suspend/resume
handlers of the driver.
Signed-off-by: Alain Volmat <alain.volmat@...com>
---
drivers/i2c/busses/i2c-stm32f7.c | 48 +++++++++++++++++++++++++++++++++-------
1 file changed, 40 insertions(+), 8 deletions(-)
diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
index 844a22d64aa8..1a3b3fa582ff 100644
--- a/drivers/i2c/busses/i2c-stm32f7.c
+++ b/drivers/i2c/busses/i2c-stm32f7.c
@@ -303,6 +303,8 @@ struct stm32f7_i2c_msg {
* @dma: dma data
* @use_dma: boolean to know if dma is used in the current transfer
* @regmap: holds SYSCFG phandle for Fast Mode Plus bits
+ * @regmap_reg: register address for setting Fast Mode Plus bits
+ * @regmap_mask: mask for Fast Mode Plus bits in set register
* @wakeup_src: boolean to know if the device is a wakeup source
*/
struct stm32f7_i2c_dev {
@@ -326,6 +328,8 @@ struct stm32f7_i2c_dev {
struct stm32_i2c_dma *dma;
bool use_dma;
struct regmap *regmap;
+ u32 regmap_reg;
+ u32 regmap_mask;
bool wakeup_src;
};
@@ -1815,12 +1819,25 @@ static int stm32f7_i2c_unreg_slave(struct i2c_client *slave)
return 0;
}
+static int stm32f7_i2c_write_fm_plus_bits(struct stm32f7_i2c_dev *i2c_dev,
+ bool enable)
+{
+ if (i2c_dev->speed != STM32_I2C_SPEED_FAST_PLUS ||
+ IS_ERR_OR_NULL(i2c_dev->regmap)) {
+ /* Optional */
+ return 0;
+ }
+
+ return regmap_update_bits(i2c_dev->regmap, i2c_dev->regmap_reg,
+ i2c_dev->regmap_mask,
+ enable ? i2c_dev->regmap_mask : 0);
+}
+
static int stm32f7_i2c_setup_fm_plus_bits(struct platform_device *pdev,
struct stm32f7_i2c_dev *i2c_dev)
{
struct device_node *np = pdev->dev.of_node;
int ret;
- u32 reg, mask;
i2c_dev->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg-fmp");
if (IS_ERR(i2c_dev->regmap)) {
@@ -1828,15 +1845,17 @@ static int stm32f7_i2c_setup_fm_plus_bits(struct platform_device *pdev,
return 0;
}
- ret = of_property_read_u32_index(np, "st,syscfg-fmp", 1, ®);
+ ret = of_property_read_u32_index(np, "st,syscfg-fmp", 1,
+ &i2c_dev->regmap_reg);
if (ret)
return ret;
- ret = of_property_read_u32_index(np, "st,syscfg-fmp", 2, &mask);
+ ret = of_property_read_u32_index(np, "st,syscfg-fmp", 2,
+ &i2c_dev->regmap_mask);
if (ret)
return ret;
- return regmap_update_bits(i2c_dev->regmap, reg, mask, mask);
+ return 0;
}
static u32 stm32f7_i2c_func(struct i2c_adapter *adap)
@@ -1914,9 +1933,6 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
&clk_rate);
if (!ret && clk_rate >= 1000000) {
i2c_dev->speed = STM32_I2C_SPEED_FAST_PLUS;
- ret = stm32f7_i2c_setup_fm_plus_bits(pdev, i2c_dev);
- if (ret)
- goto clk_free;
} else if (!ret && clk_rate >= 400000) {
i2c_dev->speed = STM32_I2C_SPEED_FAST;
} else if (!ret && clk_rate >= 100000) {
@@ -1976,6 +1992,15 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
if (ret)
goto clk_free;
+ if (i2c_dev->speed == STM32_I2C_SPEED_FAST_PLUS) {
+ ret = stm32f7_i2c_setup_fm_plus_bits(pdev, i2c_dev);
+ if (ret)
+ goto clk_free;
+ ret = stm32f7_i2c_write_fm_plus_bits(i2c_dev, 1);
+ if (ret)
+ goto clk_free;
+ }
+
adap = &i2c_dev->adap;
i2c_set_adapdata(adap, i2c_dev);
snprintf(adap->name, sizeof(adap->name), "STM32F7 I2C(%pa)",
@@ -2000,7 +2025,7 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
if (ret != -EPROBE_DEFER)
dev_err(&pdev->dev,
"Failed to request dma error %i\n", ret);
- goto clk_free;
+ goto fmp_clear;
}
if (i2c_dev->wakeup_src) {
@@ -2054,6 +2079,9 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
i2c_dev->dma = NULL;
}
+fmp_clear:
+ stm32f7_i2c_write_fm_plus_bits(i2c_dev, 0);
+
clk_free:
clk_disable_unprepare(i2c_dev->clk);
@@ -2086,6 +2114,8 @@ static int stm32f7_i2c_remove(struct platform_device *pdev)
i2c_dev->dma = NULL;
}
+ stm32f7_i2c_write_fm_plus_bits(i2c_dev, 0);
+
clk_disable_unprepare(i2c_dev->clk);
return 0;
@@ -2133,6 +2163,7 @@ stm32f7_i2c_regs_backup(struct stm32f7_i2c_dev *i2c_dev)
backup_regs->oar2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR2);
backup_regs->pecr = readl_relaxed(i2c_dev->base + STM32F7_I2C_PECR);
backup_regs->tmgr = readl_relaxed(i2c_dev->base + STM32F7_I2C_TIMINGR);
+ stm32f7_i2c_write_fm_plus_bits(i2c_dev, 0);
pm_runtime_put_sync(i2c_dev->dev);
@@ -2165,6 +2196,7 @@ stm32f7_i2c_regs_restore(struct stm32f7_i2c_dev *i2c_dev)
writel_relaxed(backup_regs->oar1, i2c_dev->base + STM32F7_I2C_OAR1);
writel_relaxed(backup_regs->oar2, i2c_dev->base + STM32F7_I2C_OAR2);
writel_relaxed(backup_regs->pecr, i2c_dev->base + STM32F7_I2C_PECR);
+ stm32f7_i2c_write_fm_plus_bits(i2c_dev, 1);
pm_runtime_put_sync(i2c_dev->dev);
--
2.7.4
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