diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index f8776065ad1f1925494f5233c013c9a9f4089fbc..d942d62e95eb33bddc233e0c96fcc11fae0d95f9 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1030,6 +1030,25 @@ int clk_rate_exclusive_get(struct clk *clk) } EXPORT_SYMBOL_GPL(clk_rate_exclusive_get); +static void devm_clk_rate_exclusive_put(void *data) +{ + struct clk *clk = data; + + clk_rate_exclusive_put(clk); +} + +int devm_clk_rate_exclusive_get(struct device *dev, struct clk *clk) +{ + int ret; + + ret = clk_rate_exclusive_get(clk); + if (ret) + return ret; + + return devm_add_action_or_reset(dev, devm_clk_rate_exclusive_put, clk); +} +EXPORT_SYMBOL_GPL(devm_clk_rate_exclusive_get); + static void clk_core_unprepare(struct clk_core *core) { lockdep_assert_held(&prepare_lock); diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c b/drivers/i2c/busses/i2c-imx-lpi2c.c index 678b30e90492ad17294453a5e6c482007946e8f5..14473c223cfa7858e6e5df1459329938961ec435 100644 --- a/drivers/i2c/busses/i2c-imx-lpi2c.c +++ b/drivers/i2c/busses/i2c-imx-lpi2c.c @@ -99,6 +99,7 @@ struct lpi2c_imx_struct { __u8 *rx_buf; __u8 *tx_buf; struct completion complete; + unsigned long rate_per; unsigned int msglen; unsigned int delivered; unsigned int block_data; @@ -207,9 +208,7 @@ static int lpi2c_imx_config(struct lpi2c_imx_struct *lpi2c_imx) lpi2c_imx_set_mode(lpi2c_imx); - clk_rate = clk_get_rate(lpi2c_imx->clks[0].clk); - if (!clk_rate) - return -EINVAL; + clk_rate = lpi2c_imx->rate_per; if (lpi2c_imx->mode == HS || lpi2c_imx->mode == ULTRA_FAST) filt = 0; @@ -590,6 +589,20 @@ static int lpi2c_imx_probe(struct platform_device *pdev) if (ret) return ret; + /* + * Lock the parent clock rate to avoid getting parent clock upon + * each transfer + */ + ret = devm_clk_rate_exclusive_get(&pdev->dev, lpi2c_imx->clks[0].clk); + if (ret) + return dev_err_probe(&pdev->dev, ret, + "can't lock I2C peripheral clock rate\n"); + + lpi2c_imx->rate_per = clk_get_rate(lpi2c_imx->clks[0].clk); + if (!lpi2c_imx->rate_per) + return dev_err_probe(&pdev->dev, -EINVAL, + "can't get I2C peripheral clock rate\n"); + pm_runtime_set_autosuspend_delay(&pdev->dev, I2C_PM_TIMEOUT); pm_runtime_use_autosuspend(&pdev->dev); pm_runtime_get_noresume(&pdev->dev); diff --git a/include/linux/clk.h b/include/linux/clk.h index 06f1b292f8a00ad8f9221a2672baa71b9b6d41e7..d01a5de97b01e2caa694874047afaa315a2054b1 100644 --- a/include/linux/clk.h +++ b/include/linux/clk.h @@ -201,6 +201,18 @@ bool clk_is_match(const struct clk *p, const struct clk *q); */ int clk_rate_exclusive_get(struct clk *clk); +/** + * devm_clk_rate_exclusive_get - devm variant of clk_rate_exclusive_get + * @dev: device the exclusivity is bound to + * @clk: clock source + * + * Calls clk_rate_exclusive_get() on @clk and registers a devm cleanup handler + * on @dev to call clk_rate_exclusive_put(). + * + * Must not be called from within atomic context. + */ +int devm_clk_rate_exclusive_get(struct device *dev, struct clk *clk); + /** * clk_rate_exclusive_put - release exclusivity over the rate control of a * producer @@ -274,6 +286,11 @@ static inline int clk_rate_exclusive_get(struct clk *clk) return 0; } +static inline int devm_clk_rate_exclusive_get(struct device *dev, struct clk *clk) +{ + return 0; +} + static inline void clk_rate_exclusive_put(struct clk *clk) {} #endif