7 files changed, 72 insertions, 22 deletions

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 8fc3808d7a3e..90c5c7357a50 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 ecb76909e946..c6e05078d3ad 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 d10386528c9c..e5187c0ade9f 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 02ce18d5e49a..057465e0553c 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 3c2ad284ee3e..4b6688909fee 100644
--- a/drivers/pwm/pwm-tiecap.c
+++ b/drivers/pwm/pwm-tiecap.c
@@ -100,6 +100,13 @@ static int ecap_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
                 writel(period_cycles, pc->mmio_base + CAP3);
         }
 
+        if (!test_bit(PWMF_ENABLED, &pwm->flags)) {
+                reg_val = readw(pc->mmio_base + ECCTL2);
+                /* Disable APWM mode to put APWM output Low */
+                reg_val &= ~ECCTL2_APWM_MODE;
+                writew(reg_val, pc->mmio_base + ECCTL2);
+        }
+
         pm_runtime_put_sync(pc->chip.dev);
         return 0;
 }
@@ -192,10 +199,8 @@ 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 010d232cb0c8..b1996bcd5b78 100644
--- a/drivers/pwm/pwm-tiehrpwm.c
+++ b/drivers/pwm/pwm-tiehrpwm.c
@@ -104,6 +104,7 @@ struct ehrpwm_pwm_chip {
         struct pwm_chip chip;
         unsigned int    clk_rate;
         void __iomem    *mmio_base;
+        unsigned long period_cycles[NUM_PWM_CHANNEL];
 };
 
 static inline struct ehrpwm_pwm_chip *to_ehrpwm_pwm_chip(struct pwm_chip *chip)
@@ -210,6 +211,7 @@ static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
         unsigned long long c;
         unsigned long period_cycles, duty_cycles;
         unsigned short ps_divval, tb_divval;
+        int i;
 
         if (period_ns < 0 || duty_ns < 0 || period_ns > NSEC_PER_SEC)
                 return -ERANGE;
@@ -229,6 +231,28 @@ static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
                 duty_cycles = (unsigned long)c;
         }
 
+        /*
+         * Period values should be same for multiple PWM channels as IP uses
+         * same period register for multiple channels.
+         */
+        for (i = 0; i < NUM_PWM_CHANNEL; i++) {
+                if (pc->period_cycles[i] &&
+                                (pc->period_cycles[i] != period_cycles)) {
+                        /*
+                         * Allow channel to reconfigure period if no other
+                         * channels being configured.
+                         */
+                        if (i == pwm->hwpwm)
+                                continue;
+
+                        dev_err(chip->dev, "Period value conflicts with channel %d\n",
+                                        i);
+                        return -EINVAL;
+                }
+        }
+
+        pc->period_cycles[pwm->hwpwm] = period_cycles;
+
         /* Configure clock prescaler to support Low frequency PWM wave */
         if (set_prescale_div(period_cycles/PERIOD_MAX, &ps_divval,
                                 &tb_divval)) {
@@ -320,10 +344,15 @@ static void ehrpwm_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 
 static void ehrpwm_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 {
+        struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
+
         if (test_bit(PWMF_ENABLED, &pwm->flags)) {
                 dev_warn(chip->dev, "Removing PWM device without disabling\n");
                 pm_runtime_put_sync(chip->dev);
         }
+
+        /* set period value to zero on free */
+        pc->period_cycles[pwm->hwpwm] = 0;
 }
 
 static const struct pwm_ops ehrpwm_pwm_ops = {
@@ -371,10 +400,8 @@ 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 548021439f0c..ad14389b7144 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);
 }