Commit 3347ea9b authored by Alain Volmat's avatar Alain Volmat Committed by Wolfram Sang
Browse files

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: default avatarAlain Volmat <alain.volmat@st.com>
Reviewed-by: default avatarPierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent d31f59ea

drivers/i2c/busses/i2c-stm32f7.c

+39 −13
Original line number Diff line number Diff line
@@ -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

 * @fmp_reg: register address for setting Fast Mode Plus bits

 * @fmp_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 fmp_reg;

	u32 fmp_mask;

	bool wakeup_src;

};
@@ -1830,28 +1834,37 @@ 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->fmp_reg,

				  i2c_dev->fmp_mask,

				  enable ? i2c_dev->fmp_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)) {

	if (IS_ERR(i2c_dev->regmap))

		/* Optional */

		return 0;

	}



	ret = of_property_read_u32_index(np, "st,syscfg-fmp", 1, &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", 1,

					 &i2c_dev->fmp_reg);

	if (ret)

		return ret;



	return regmap_update_bits(i2c_dev->regmap, reg, mask, mask);

	return of_property_read_u32_index(np, "st,syscfg-fmp", 2,

					  &i2c_dev->fmp_mask);

}



static u32 stm32f7_i2c_func(struct i2c_adapter *adap)
@@ -1929,9 +1942,6 @@ 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) {
@@ -1991,6 +2001,15 @@ 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, true);

		if (ret)

			goto clk_free;

	}



	adap = &i2c_dev->adap;

	i2c_set_adapdata(adap, i2c_dev);

	snprintf(adap->name, sizeof(adap->name), "STM32F7 I2C(%pa)",
@@ -2015,7 +2034,7 @@ 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) {
@@ -2069,6 +2088,9 @@ clr_wakeup_capable: 
		i2c_dev->dma = NULL;

	}



fmp_clear:

	stm32f7_i2c_write_fm_plus_bits(i2c_dev, false);



clk_free:

	clk_disable_unprepare(i2c_dev->clk);
@@ -2101,6 +2123,8 @@ static int stm32f7_i2c_remove(struct platform_device *pdev) 
		i2c_dev->dma = NULL;

	}



	stm32f7_i2c_write_fm_plus_bits(i2c_dev, false);



	clk_disable_unprepare(i2c_dev->clk);



	return 0;
@@ -2148,6 +2172,7 @@ static int 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, false);



	pm_runtime_put_sync(i2c_dev->dev);
@@ -2179,6 +2204,7 @@ static int 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, true);



	pm_runtime_put_sync(i2c_dev->dev);

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