diff options
Diffstat (limited to 'drivers/misc/ab8500-pwm.c')
| -rw-r--r-- | drivers/misc/ab8500-pwm.c | 45 |
1 files changed, 43 insertions, 2 deletions
diff --git a/drivers/misc/ab8500-pwm.c b/drivers/misc/ab8500-pwm.c index d7a9aa14e5d..7a928667169 100644 --- a/drivers/misc/ab8500-pwm.c +++ b/drivers/misc/ab8500-pwm.c @@ -8,6 +8,7 @@ #include <linux/platform_device.h> #include <linux/slab.h> #include <linux/pwm.h> +#include <linux/clk.h> #include <linux/mfd/abx500.h> #include <linux/mfd/abx500/ab8500.h> #include <linux/module.h> @@ -27,8 +28,10 @@ struct pwm_device { struct device *dev; struct list_head node; + struct clk *clk; const char *label; unsigned int pwm_id; + bool clk_enabled; }; static LIST_HEAD(pwm_list); @@ -67,9 +70,17 @@ int pwm_enable(struct pwm_device *pwm) { int ret; + if (!pwm->clk_enabled) { + ret = clk_enable(pwm->clk); + if (ret < 0) { + dev_err(pwm->dev, "failed to enable clock\n"); + return ret; + } + pwm->clk_enabled = true; + } ret = abx500_mask_and_set_register_interruptible(pwm->dev, AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG, - 1 << (pwm->pwm_id-1), ENABLE_PWM); + 1 << (pwm->pwm_id-1), 1 << (pwm->pwm_id-1)); if (ret < 0) dev_err(pwm->dev, "%s: Failed to disable PWM, Error %d\n", pwm->label, ret); @@ -84,9 +95,27 @@ void pwm_disable(struct pwm_device *pwm) ret = abx500_mask_and_set_register_interruptible(pwm->dev, AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG, 1 << (pwm->pwm_id-1), DISABLE_PWM); + /* + * Workaround to set PWM in disable. + * If enable bit is not toggled the PWM might output 50/50 duty cycle + * even though it should be disabled + */ + ret &= abx500_mask_and_set_register_interruptible(pwm->dev, + AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG, + 1 << (pwm->pwm_id-1), + ENABLE_PWM << (pwm->pwm_id-1)); + ret &= abx500_mask_and_set_register_interruptible(pwm->dev, + AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG, + 1 << (pwm->pwm_id-1), DISABLE_PWM); + if (ret < 0) dev_err(pwm->dev, "%s: Failed to disable PWM, Error %d\n", pwm->label, ret); + if (pwm->clk_enabled) { + clk_disable(pwm->clk); + pwm->clk_enabled = false; + } + return; } EXPORT_SYMBOL(pwm_disable); @@ -116,6 +145,8 @@ EXPORT_SYMBOL(pwm_free); static int __devinit ab8500_pwm_probe(struct platform_device *pdev) { struct pwm_device *pwm; + int ret = 0; + /* * Nothing to be done in probe, this is required to get the * device which is required for ab8500 read and write @@ -129,14 +160,24 @@ static int __devinit ab8500_pwm_probe(struct platform_device *pdev) pwm->pwm_id = pdev->id; list_add_tail(&pwm->node, &pwm_list); platform_set_drvdata(pdev, pwm); + + pwm->clk = clk_get(pwm->dev, NULL); + if (IS_ERR(pwm->clk)) { + dev_err(pwm->dev, "clock request failed\n"); + ret = PTR_ERR(pwm->clk); + kfree(pwm); + return ret; + } + pwm->clk_enabled = false; dev_dbg(pwm->dev, "pwm probe successful\n"); - return 0; + return ret; } static int __devexit ab8500_pwm_remove(struct platform_device *pdev) { struct pwm_device *pwm = platform_get_drvdata(pdev); list_del(&pwm->node); + clk_put(pwm->clk); dev_dbg(&pdev->dev, "pwm driver removed\n"); kfree(pwm); return 0; |