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Message-ID: <4e92ad2d-d373-f009-7c79-63d7caafac45@st.com>
Date: Mon, 27 Jan 2020 10:18:57 +0100
From: Pierre Yves MORDRET <pierre-yves.mordret@...com>
To: Alain Volmat <alain.volmat@...com>, <wsa@...-dreams.de>,
<robh+dt@...nel.org>
CC: <mark.rutland@....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>
Subject: Re: [PATCH 1/5] i2c: i2c-stm32f7: disable/restore Fast Mode Plus bits
in low power modes
Hello
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@...com>
Thanks
On 1/23/20 5:12 PM, Alain Volmat wrote:
> 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);
>
>
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