diff options
Diffstat (limited to 'drivers/pwm')
| -rw-r--r-- | drivers/pwm/Kconfig | 31 | ||||
| -rw-r--r-- | drivers/pwm/core.c | 12 | ||||
| -rw-r--r-- | drivers/pwm/pwm-samsung.c | 1 | ||||
| -rw-r--r-- | drivers/pwm/pwm-tegra.c | 4 | ||||
| -rw-r--r-- | drivers/pwm/pwm-tiecap.c | 4 | ||||
| -rw-r--r-- | drivers/pwm/pwm-tiehrpwm.c | 4 | ||||
| -rw-r--r-- | drivers/pwm/pwm-vt8500.c | 2 |
7 files changed, 36 insertions, 22 deletions
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index 8fc3808d7a3..90c5c7357a5 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -1,12 +1,31 @@ menuconfig PWM - bool "PWM Support" + bool "Pulse-Width Modulation (PWM) Support" depends on !MACH_JZ4740 && !PUV3_PWM help - This enables PWM support through the generic PWM framework. - You only need to enable this, if you also want to enable - one or more of the PWM drivers below. - - If unsure, say N. + Generic Pulse-Width Modulation (PWM) support. + + In Pulse-Width Modulation, a variation of the width of pulses + in a rectangular pulse signal is used as a means to alter the + average power of the signal. Applications include efficient + power delivery and voltage regulation. In computer systems, + PWMs are commonly used to control fans or the brightness of + display backlights. + + This framework provides a generic interface to PWM devices + within the Linux kernel. On the driver side it provides an API + to register and unregister a PWM chip, an abstraction of a PWM + controller, that supports one or more PWM devices. Client + drivers can request PWM devices and use the generic framework + to configure as well as enable and disable them. + + This generic framework replaces the legacy PWM framework which + allows only a single driver implementing the required API. Not + all legacy implementations have been ported to the framework + yet. The framework provides an API that is backward compatible + with the legacy framework so that existing client drivers + continue to work as expected. + + If unsure, say no. if PWM diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index ecb76909e94..c6e05078d3a 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -129,8 +129,8 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label) return 0; } -static struct pwm_device *of_pwm_simple_xlate(struct pwm_chip *pc, - const struct of_phandle_args *args) +static struct pwm_device * +of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args) { struct pwm_device *pwm; @@ -149,7 +149,7 @@ static struct pwm_device *of_pwm_simple_xlate(struct pwm_chip *pc, return pwm; } -void of_pwmchip_add(struct pwm_chip *chip) +static void of_pwmchip_add(struct pwm_chip *chip) { if (!chip->dev || !chip->dev->of_node) return; @@ -162,7 +162,7 @@ void of_pwmchip_add(struct pwm_chip *chip) of_node_get(chip->dev->of_node); } -void of_pwmchip_remove(struct pwm_chip *chip) +static void of_pwmchip_remove(struct pwm_chip *chip) { if (chip->dev && chip->dev->of_node) of_node_put(chip->dev->of_node); @@ -527,7 +527,7 @@ void __init pwm_add_table(struct pwm_lookup *table, size_t num) struct pwm_device *pwm_get(struct device *dev, const char *con_id) { struct pwm_device *pwm = ERR_PTR(-EPROBE_DEFER); - const char *dev_id = dev ? dev_name(dev): NULL; + const char *dev_id = dev ? dev_name(dev) : NULL; struct pwm_chip *chip = NULL; unsigned int index = 0; unsigned int best = 0; @@ -609,7 +609,7 @@ void pwm_put(struct pwm_device *pwm) mutex_lock(&pwm_lock); if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) { - pr_warning("PWM device already freed\n"); + pr_warn("PWM device already freed\n"); goto out; } diff --git a/drivers/pwm/pwm-samsung.c b/drivers/pwm/pwm-samsung.c index d10386528c9..e5187c0ade9 100644 --- a/drivers/pwm/pwm-samsung.c +++ b/drivers/pwm/pwm-samsung.c @@ -225,6 +225,7 @@ static int s3c_pwm_probe(struct platform_device *pdev) /* calculate base of control bits in TCON */ s3c->tcon_base = id == 0 ? 0 : (id * 4) + 4; + s3c->chip.dev = &pdev->dev; s3c->chip.ops = &s3c_pwm_ops; s3c->chip.base = -1; s3c->chip.npwm = 1; diff --git a/drivers/pwm/pwm-tegra.c b/drivers/pwm/pwm-tegra.c index 02ce18d5e49..057465e0553 100644 --- a/drivers/pwm/pwm-tegra.c +++ b/drivers/pwm/pwm-tegra.c @@ -187,10 +187,8 @@ static int tegra_pwm_probe(struct platform_device *pdev) } pwm->mmio_base = devm_request_and_ioremap(&pdev->dev, r); - if (!pwm->mmio_base) { - dev_err(&pdev->dev, "failed to ioremap() region\n"); + if (!pwm->mmio_base) return -EADDRNOTAVAIL; - } platform_set_drvdata(pdev, pwm); diff --git a/drivers/pwm/pwm-tiecap.c b/drivers/pwm/pwm-tiecap.c index 3c2ad284ee3..0b66d0f2592 100644 --- a/drivers/pwm/pwm-tiecap.c +++ b/drivers/pwm/pwm-tiecap.c @@ -192,10 +192,8 @@ static int __devinit ecap_pwm_probe(struct platform_device *pdev) } pc->mmio_base = devm_request_and_ioremap(&pdev->dev, r); - if (!pc->mmio_base) { - dev_err(&pdev->dev, "failed to ioremap() registers\n"); + if (!pc->mmio_base) return -EADDRNOTAVAIL; - } ret = pwmchip_add(&pc->chip); if (ret < 0) { diff --git a/drivers/pwm/pwm-tiehrpwm.c b/drivers/pwm/pwm-tiehrpwm.c index 010d232cb0c..c3756d1be19 100644 --- a/drivers/pwm/pwm-tiehrpwm.c +++ b/drivers/pwm/pwm-tiehrpwm.c @@ -371,10 +371,8 @@ static int __devinit ehrpwm_pwm_probe(struct platform_device *pdev) } pc->mmio_base = devm_request_and_ioremap(&pdev->dev, r); - if (!pc->mmio_base) { - dev_err(&pdev->dev, "failed to ioremap() registers\n"); + if (!pc->mmio_base) return -EADDRNOTAVAIL; - } ret = pwmchip_add(&pc->chip); if (ret < 0) { diff --git a/drivers/pwm/pwm-vt8500.c b/drivers/pwm/pwm-vt8500.c index 548021439f0..ad14389b714 100644 --- a/drivers/pwm/pwm-vt8500.c +++ b/drivers/pwm/pwm-vt8500.c @@ -41,7 +41,7 @@ static inline void pwm_busy_wait(void __iomem *reg, u8 bitmask) cpu_relax(); if (unlikely(!loops)) - pr_warning("Waiting for status bits 0x%x to clear timed out\n", + pr_warn("Waiting for status bits 0x%x to clear timed out\n", bitmask); } |