diff options
author | Grygorii Strashko <grygorii.strashko@ti.com> | 2015-08-18 11:10:56 (GMT) |
---|---|---|
committer | Linus Walleij <linus.walleij@linaro.org> | 2015-08-26 07:52:57 (GMT) |
commit | 5d9452e7c52a106c9efdeb6c72fc73b184a6543f (patch) | |
tree | 0d08d160aa82706573c533c58bd80dcae0e6bbd4 | |
parent | 235f1eb1ab93a8e30a66c38949e6d2aeda136aec (diff) | |
download | linux-5d9452e7c52a106c9efdeb6c72fc73b184a6543f.tar.xz |
gpio: omap: fix clk_prepare/unprepare usage
As per CCF documentation (clk.txt) the clk_prepare/unprepare APIs
are not allowed in atomic context. But now OMAP GPIO driver
uses them while applying debounce settings and as part
of PM runtime irqsafe operations:
- omap_gpio_debounce() is holding the lock with IRQs off.
+ omap2_set_gpio_debounce()
+ clk_prepare_enable()
+ clk_prepare() this one might sleep.
- pm_runtime_get_sync() is holding the lock with IRQs off
+ omap_gpio_runtime_suspend()
+ raw_spin_lock_irqsave()
+ omap_gpio_dbck_disable()
+ clk_disable_unprepare()
Hence, fix it by moeving dbclk prepare/unprepare in OMAP GPIO
omap_gpio_probe/omap_gpio_remove. Also, while here, ensure that
debounce functionality is disabled if clk_get() failed,
because otherwise kernel will carsh in omap2_set_gpio_debounce().
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
-rw-r--r-- | drivers/gpio/gpio-omap.c | 27 |
1 files changed, 18 insertions, 9 deletions
diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c index 1f02acd..2ae0d47 100644 --- a/drivers/gpio/gpio-omap.c +++ b/drivers/gpio/gpio-omap.c @@ -176,7 +176,7 @@ static inline void omap_gpio_rmw(void __iomem *base, u32 reg, u32 mask, bool set static inline void omap_gpio_dbck_enable(struct gpio_bank *bank) { if (bank->dbck_enable_mask && !bank->dbck_enabled) { - clk_prepare_enable(bank->dbck); + clk_enable(bank->dbck); bank->dbck_enabled = true; writel_relaxed(bank->dbck_enable_mask, @@ -194,7 +194,7 @@ static inline void omap_gpio_dbck_disable(struct gpio_bank *bank) */ writel_relaxed(0, bank->base + bank->regs->debounce_en); - clk_disable_unprepare(bank->dbck); + clk_disable(bank->dbck); bank->dbck_enabled = false; } } @@ -227,7 +227,7 @@ static void omap2_set_gpio_debounce(struct gpio_bank *bank, unsigned offset, l = BIT(offset); - clk_prepare_enable(bank->dbck); + clk_enable(bank->dbck); reg = bank->base + bank->regs->debounce; writel_relaxed(debounce, reg); @@ -241,7 +241,7 @@ static void omap2_set_gpio_debounce(struct gpio_bank *bank, unsigned offset, bank->dbck_enable_mask = val; writel_relaxed(val, reg); - clk_disable_unprepare(bank->dbck); + clk_disable(bank->dbck); /* * Enable debounce clock per module. * This call is mandatory because in omap_gpio_request() when @@ -286,7 +286,7 @@ static void omap_clear_gpio_debounce(struct gpio_bank *bank, unsigned offset) bank->context.debounce = 0; writel_relaxed(bank->context.debounce, bank->base + bank->regs->debounce); - clk_disable_unprepare(bank->dbck); + clk_disable(bank->dbck); bank->dbck_enabled = false; } } @@ -1070,10 +1070,6 @@ static void omap_gpio_mod_init(struct gpio_bank *bank) /* Initialize interface clk ungated, module enabled */ if (bank->regs->ctrl) writel_relaxed(0, base + bank->regs->ctrl); - - bank->dbck = clk_get(bank->dev, "dbclk"); - if (IS_ERR(bank->dbck)) - dev_err(bank->dev, "Could not get gpio dbck\n"); } static int omap_gpio_chip_init(struct gpio_bank *bank, struct irq_chip *irqc) @@ -1234,6 +1230,17 @@ static int omap_gpio_probe(struct platform_device *pdev) return PTR_ERR(bank->base); } + if (bank->dbck_flag) { + bank->dbck = devm_clk_get(bank->dev, "dbclk"); + if (IS_ERR(bank->dbck)) { + dev_err(bank->dev, + "Could not get gpio dbck. Disable debounce\n"); + bank->dbck_flag = false; + } else { + clk_prepare(bank->dbck); + } + } + platform_set_drvdata(pdev, bank); pm_runtime_enable(bank->dev); @@ -1265,6 +1272,8 @@ static int omap_gpio_remove(struct platform_device *pdev) list_del(&bank->node); gpiochip_remove(&bank->chip); pm_runtime_disable(bank->dev); + if (bank->dbck_flag) + clk_unprepare(bank->dbck); return 0; } |