pwm: Changes for v4.2-rc1

This has a couple of fixes for Atmel, Samsung and Broadcom drivers. Some
 preparatory patches for more upcoming Intel work is included as well.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQIcBAABCAAGBQJVevH0AAoJEN0jrNd/PrOhUDsP/0N3DTBrwHGY2TRtniXK5PsX
 Dz9Txm1dUlSRc/4QmYfmBPB3GzgtbKMAXP/SJBJ5SP48RZYvzjfHLxEKEoJqkMg+
 h9btE1fReQ50H0HmH4L8+jkjSsA15m39T5yuX+KR5P6Uxv7WFMyVDgBw4dmARIzK
 wOwuy8r+6ZtAdsj+o0eSoOxs64HgUiJRN/9FDJi9fPGi27smAXH2Nef5uja9upnt
 CR+ntOxYXXRJM2JnW9ObPK87wvZsiIJw1QrRIWPRaUesZjXxH+11eTKS4YaSjnhz
 93aLDWXVBm9goXeYnqe+aRq0PHIRIHcND6Fh4+cb42dVYdINnW6h9Y9WBSUeVHwx
 cKumJUU6wBbTSUUWKnvGi1NFmrMvxbf3knE0maQjswHOf5SEdCh0q/VNh/HWGGPI
 sglqjl5KmJPx9Afr97RNNqymYS9ECT0yHajY+5ivgvD4XlPFam2NPpyi1CjJaqaU
 rnwhabnpnpq7zeD78f5gvLSENWvwnYCVQTwp0YLkJ2o+9gGPh+FuJ6KcZ3m7LGXC
 jb1VuAy+0896eP3VlK1LqwDkyBVFkWZQqwuLnER6zHuMTetx0tfosj8Nenv0z+fv
 VccUDgYuh8G/SHYNDVdpRmHDIb34ZpMjSxbXaFOKTPsxAhlNfu4ylcrKZijIkK+a
 YmYJgj9pGqww50LVK0R/
 =VmI2
 -----END PGP SIGNATURE-----

Merge tag 'pwm/for-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "This has a couple of fixes for Atmel, Samsung and Broadcom drivers.

  Some preparatory patches for more upcoming Intel work is included as
  well"

* tag 'pwm/for-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm:
  pwm: lpss: pci: Add support for Broxton platform
  pwm: bcm-kona: Don't set polarity in probe
  pwm: Add pwmchip_add_with_polarity() API
  pwm: atmel: Fix incorrect CDTY value after disabling
  pwm: atmel: Fix incorrect CDTY value after enabling
  pwm: samsung: Use MODULE_DEVICE_TABLE() to include OF modalias
  pwm: Add support to remove registered consumer lookup tables

drivers/pwm/core.c

@@ -223,13 +223,16 @@ void *pwm_get_chip_data(struct pwm_device *pwm)
 EXPORT_SYMBOL_GPL(pwm_get_chip_data);
 
 /**
- * pwmchip_add() - register a new PWM chip
+ * pwmchip_add_with_polarity() - register a new PWM chip
  * @chip: the PWM chip to add
+ * @polarity: initial polarity of PWM channels
  *
  * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
- * will be used.
+ * will be used. The initial polarity for all channels is specified by the
+ * @polarity parameter.
  */
-int pwmchip_add(struct pwm_chip *chip)
+int pwmchip_add_with_polarity(struct pwm_chip *chip,
+			      enum pwm_polarity polarity)
 {
 	struct pwm_device *pwm;
 	unsigned int i;
@@ -259,6 +262,7 @@ int pwmchip_add(struct pwm_chip *chip)
 		pwm->chip = chip;
 		pwm->pwm = chip->base + i;
 		pwm->hwpwm = i;
+		pwm->polarity = polarity;
 
 		radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
 	}
@@ -279,6 +283,19 @@ out:
 	mutex_unlock(&pwm_lock);
 	return ret;
 }
+EXPORT_SYMBOL_GPL(pwmchip_add_with_polarity);
+
+/**
+ * pwmchip_add() - register a new PWM chip
+ * @chip: the PWM chip to add
+ *
+ * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
+ * will be used. The initial polarity for all channels is normal.
+ */
+int pwmchip_add(struct pwm_chip *chip)
+{
+	return pwmchip_add_with_polarity(chip, PWM_POLARITY_NORMAL);
+}
 EXPORT_SYMBOL_GPL(pwmchip_add);
 
 /**
@@ -585,6 +602,23 @@ void pwm_add_table(struct pwm_lookup *table, size_t num)
 	mutex_unlock(&pwm_lookup_lock);
 }
 
+/**
+ * pwm_remove_table() - unregister PWM device consumers
+ * @table: array of consumers to unregister
+ * @num: number of consumers in table
+ */
+void pwm_remove_table(struct pwm_lookup *table, size_t num)
+{
+	mutex_lock(&pwm_lookup_lock);
+
+	while (num--) {
+		list_del(&table->list);
+		table++;
+	}
+
+	mutex_unlock(&pwm_lookup_lock);
+}
+
 /**
  * pwm_get() - look up and request a PWM device
  * @dev: device for PWM consumer

drivers/pwm/pwm-atmel.c

@@ -8,9 +8,11 @@
  */
 
 #include <linux/clk.h>
+#include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
@@ -21,6 +23,7 @@
 #define PWM_ENA			0x04
 #define PWM_DIS			0x08
 #define PWM_SR			0x0C
+#define PWM_ISR			0x1C
 /* Bit field in SR */
 #define PWM_SR_ALL_CH_ON	0x0F
 
@@ -60,6 +63,9 @@ struct atmel_pwm_chip {
 	struct clk *clk;
 	void __iomem *base;
 
+	unsigned int updated_pwms;
+	struct mutex isr_lock; /* ISR is cleared when read, ensure only one thread does that */
+
 	void (*config)(struct pwm_chip *chip, struct pwm_device *pwm,
 		       unsigned long dty, unsigned long prd);
 };
@@ -144,6 +150,10 @@ static int atmel_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	val = (val & ~PWM_CMR_CPRE_MSK) | (pres & PWM_CMR_CPRE_MSK);
 	atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val);
 	atmel_pwm->config(chip, pwm, dty, prd);
+	mutex_lock(&atmel_pwm->isr_lock);
+	atmel_pwm->updated_pwms |= atmel_pwm_readl(atmel_pwm, PWM_ISR);
+	atmel_pwm->updated_pwms &= ~(1 << pwm->hwpwm);
+	mutex_unlock(&atmel_pwm->isr_lock);
 
 	clk_disable(atmel_pwm->clk);
 	return ret;
@@ -155,24 +165,25 @@ static void atmel_pwm_config_v1(struct pwm_chip *chip, struct pwm_device *pwm,
 	struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
 	unsigned int val;
 
-	if (test_bit(PWMF_ENABLED, &pwm->flags)) {
-		/*
-		 * If the PWM channel is enabled, using the update register,
-		 * it needs to set bit 10 of CMR to 0
-		 */
-		atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV1_CUPD, dty);
 
-		val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR);
-		val &= ~PWM_CMR_UPD_CDTY;
-		atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val);
-	} else {
-		/*
-		 * If the PWM channel is disabled, write value to duty and
-		 * period registers directly.
-		 */
-		atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV1_CDTY, dty);
-		atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV1_CPRD, prd);
-	}
+	atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV1_CUPD, dty);
+
+	val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR);
+	val &= ~PWM_CMR_UPD_CDTY;
+	atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val);
+
+	/*
+	 * If the PWM channel is enabled, only update CDTY by using the update
+	 * register, it needs to set bit 10 of CMR to 0
+	 */
+	if (test_bit(PWMF_ENABLED, &pwm->flags))
+		return;
+	/*
+	 * If the PWM channel is disabled, write value to duty and period
+	 * registers directly.
+	 */
+	atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV1_CDTY, dty);
+	atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV1_CPRD, prd);
 }
 
 static void atmel_pwm_config_v2(struct pwm_chip *chip, struct pwm_device *pwm,
@@ -242,7 +253,22 @@ static int atmel_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 static void atmel_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
+	unsigned long timeout = jiffies + 2 * HZ;
 
+	/*
+	 * Wait for at least a complete period to have passed before disabling a
+	 * channel to be sure that CDTY has been updated
+	 */
+	mutex_lock(&atmel_pwm->isr_lock);
+	atmel_pwm->updated_pwms |= atmel_pwm_readl(atmel_pwm, PWM_ISR);
+
+	while (!(atmel_pwm->updated_pwms & (1 << pwm->hwpwm)) &&
+	       time_before(jiffies, timeout)) {
+		usleep_range(10, 100);
+		atmel_pwm->updated_pwms |= atmel_pwm_readl(atmel_pwm, PWM_ISR);
+	}
+
+	mutex_unlock(&atmel_pwm->isr_lock);
 	atmel_pwm_writel(atmel_pwm, PWM_DIS, 1 << pwm->hwpwm);
 
 	clk_disable(atmel_pwm->clk);
@@ -357,6 +383,8 @@ static int atmel_pwm_probe(struct platform_device *pdev)
 	atmel_pwm->chip.npwm = 4;
 	atmel_pwm->chip.can_sleep = true;
 	atmel_pwm->config = data->config;
+	atmel_pwm->updated_pwms = 0;
+	mutex_init(&atmel_pwm->isr_lock);
 
 	ret = pwmchip_add(&atmel_pwm->chip);
 	if (ret < 0) {
@@ -378,6 +406,7 @@ static int atmel_pwm_remove(struct platform_device *pdev)
 	struct atmel_pwm_chip *atmel_pwm = platform_get_drvdata(pdev);
 
 	clk_unprepare(atmel_pwm->clk);
+	mutex_destroy(&atmel_pwm->isr_lock);
 
 	return pwmchip_remove(&atmel_pwm->chip);
 }

drivers/pwm/pwm-bcm-kona.c

@@ -266,18 +266,15 @@ static int kona_pwmc_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	/* Set smooth mode, push/pull, and normal polarity for all channels */
-	for (chan = 0; chan < kp->chip.npwm; chan++) {
-		value |= (1 << PWM_CONTROL_SMOOTH_SHIFT(chan));
+	/* Set push/pull for all channels */
+	for (chan = 0; chan < kp->chip.npwm; chan++)
 		value |= (1 << PWM_CONTROL_TYPE_SHIFT(chan));
-		value |= (1 << PWM_CONTROL_POLARITY_SHIFT(chan));
-	}
 
 	writel(value, kp->base + PWM_CONTROL_OFFSET);
 
 	clk_disable_unprepare(kp->clk);
 
-	ret = pwmchip_add(&kp->chip);
+	ret = pwmchip_add_with_polarity(&kp->chip, PWM_POLARITY_INVERSED);
 	if (ret < 0)
 		dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
 

drivers/pwm/pwm-lpss-pci.c

@@ -44,8 +44,10 @@ static void pwm_lpss_remove_pci(struct pci_dev *pdev)
 }
 
 static const struct pci_device_id pwm_lpss_pci_ids[] = {
+	{ PCI_VDEVICE(INTEL, 0x0ac8), (unsigned long)&pwm_lpss_bsw_info},
 	{ PCI_VDEVICE(INTEL, 0x0f08), (unsigned long)&pwm_lpss_byt_info},
 	{ PCI_VDEVICE(INTEL, 0x0f09), (unsigned long)&pwm_lpss_byt_info},
+	{ PCI_VDEVICE(INTEL, 0x1ac8), (unsigned long)&pwm_lpss_bsw_info},
 	{ PCI_VDEVICE(INTEL, 0x2288), (unsigned long)&pwm_lpss_bsw_info},
 	{ PCI_VDEVICE(INTEL, 0x2289), (unsigned long)&pwm_lpss_bsw_info},
 	{ },

drivers/pwm/pwm-samsung.c

@@ -456,6 +456,7 @@ static const struct of_device_id samsung_pwm_matches[] = {
 	{ .compatible = "samsung,exynos4210-pwm", .data = &s5p64x0_variant },
 	{},
 };
+MODULE_DEVICE_TABLE(of, samsung_pwm_matches);
 
 static int pwm_samsung_parse_dt(struct samsung_pwm_chip *chip)
 {

include/linux/pwm.h

@@ -182,6 +182,8 @@ struct pwm_chip {
 int pwm_set_chip_data(struct pwm_device *pwm, void *data);
 void *pwm_get_chip_data(struct pwm_device *pwm);
 
+int pwmchip_add_with_polarity(struct pwm_chip *chip,
+			      enum pwm_polarity polarity);
 int pwmchip_add(struct pwm_chip *chip);
 int pwmchip_remove(struct pwm_chip *chip);
 struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
@@ -217,6 +219,11 @@ static inline int pwmchip_add(struct pwm_chip *chip)
 	return -EINVAL;
 }
 
+static inline int pwmchip_add_inversed(struct pwm_chip *chip)
+{
+	return -EINVAL;
+}
+
 static inline int pwmchip_remove(struct pwm_chip *chip)
 {
 	return -EINVAL;
@@ -290,10 +297,15 @@ struct pwm_lookup {
 
 #if IS_ENABLED(CONFIG_PWM)
 void pwm_add_table(struct pwm_lookup *table, size_t num);
+void pwm_remove_table(struct pwm_lookup *table, size_t num);
 #else
 static inline void pwm_add_table(struct pwm_lookup *table, size_t num)
 {
 }
+
+static inline void pwm_remove_table(struct pwm_lookup *table, size_t num)
+{
+}
 #endif
 
 #ifdef CONFIG_PWM_SYSFS