Merge branch 'for-4.11/drivers' into for-next

Documentation/devicetree/bindings/pwm/imx-pwm.txt

@@ -6,8 +6,8 @@ Required properties:
   - "fsl,imx1-pwm" for PWM compatible with the one integrated on i.MX1
   - "fsl,imx27-pwm" for PWM compatible with the one integrated on i.MX27
 - reg: physical base address and length of the controller's registers
-- #pwm-cells: should be 2. See pwm.txt in this directory for a description of
-  the cells format.
+- #pwm-cells: 2 for i.MX1 and 3 for i.MX27 and newer SoCs. See pwm.txt
+  in this directory for a description of the cells format.
 - clocks : Clock specifiers for both ipg and per clocks.
 - clock-names : Clock names should include both "ipg" and "per"
 See the clock consumer binding,
@@ -17,7 +17,7 @@ See the clock consumer binding,
 Example:
 
 pwm1: pwm@53fb4000 {
-	#pwm-cells = <2>;
+	#pwm-cells = <3>;
 	compatible = "fsl,imx53-pwm", "fsl,imx27-pwm";
 	reg = <0x53fb4000 0x4000>;
 	clocks = <&clks IMX5_CLK_PWM1_IPG_GATE>,

drivers/pwm/Kconfig

@@ -76,7 +76,9 @@ config PWM_ATMEL_TCB
 
 config PWM_BCM_IPROC
 	tristate "iProc PWM support"
-	depends on ARCH_BCM_IPROC
+	depends on ARCH_BCM_IPROC || COMPILE_TEST
+	depends on COMMON_CLK
+	default ARCH_BCM_IPROC
 	help
 	  Generic PWM framework driver for Broadcom iProc PWM block. This
 	  block is used in Broadcom iProc SoC's.

drivers/pwm/pwm-bfin.c

@@ -103,7 +103,7 @@ static void bfin_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 	disable_gptimer(priv->pin);
 }
 
-static struct pwm_ops bfin_pwm_ops = {
+static const struct pwm_ops bfin_pwm_ops = {
 	.request = bfin_pwm_request,
 	.free = bfin_pwm_free,
 	.config = bfin_pwm_config,

drivers/pwm/pwm-imx.c

@@ -38,6 +38,7 @@
 #define MX3_PWMCR_DOZEEN		(1 << 24)
 #define MX3_PWMCR_WAITEN		(1 << 23)
 #define MX3_PWMCR_DBGEN			(1 << 22)
+#define MX3_PWMCR_POUTC			(1 << 18)
 #define MX3_PWMCR_CLKSRC_IPG_HIGH	(2 << 16)
 #define MX3_PWMCR_CLKSRC_IPG		(1 << 16)
 #define MX3_PWMCR_SWR			(1 << 3)
@@ -49,15 +50,10 @@
 
 struct imx_chip {
 	struct clk	*clk_per;
-	struct clk	*clk_ipg;
 
 	void __iomem	*mmio_base;
 
 	struct pwm_chip	chip;
-
-	int (*config)(struct pwm_chip *chip,
-		struct pwm_device *pwm, int duty_ns, int period_ns);
-	void (*set_enable)(struct pwm_chip *chip, bool enable);
 };
 
 #define to_imx_chip(chip)	container_of(chip, struct imx_chip, chip)
@@ -91,41 +87,62 @@ static int imx_pwm_config_v1(struct pwm_chip *chip,
 	return 0;
 }
 
-static void imx_pwm_set_enable_v1(struct pwm_chip *chip, bool enable)
+static int imx_pwm_enable_v1(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct imx_chip *imx = to_imx_chip(chip);
 	u32 val;
+	int ret;
 
-	val = readl(imx->mmio_base + MX1_PWMC);
+	ret = clk_prepare_enable(imx->clk_per);
+	if (ret < 0)
+		return ret;
 
-	if (enable)
+	val = readl(imx->mmio_base + MX1_PWMC);
 	val |= MX1_PWMC_EN;
-	else
-		val &= ~MX1_PWMC_EN;
+	writel(val, imx->mmio_base + MX1_PWMC);
+
+	return 0;
+}
 
+static void imx_pwm_disable_v1(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct imx_chip *imx = to_imx_chip(chip);
+	u32 val;
+
+	val = readl(imx->mmio_base + MX1_PWMC);
+	val &= ~MX1_PWMC_EN;
 	writel(val, imx->mmio_base + MX1_PWMC);
+
+	clk_disable_unprepare(imx->clk_per);
 }
 
-static int imx_pwm_config_v2(struct pwm_chip *chip,
-		struct pwm_device *pwm, int duty_ns, int period_ns)
+static void imx_pwm_sw_reset(struct pwm_chip *chip)
+{
+	struct imx_chip *imx = to_imx_chip(chip);
+	struct device *dev = chip->dev;
+	int wait_count = 0;
+	u32 cr;
+
+	writel(MX3_PWMCR_SWR, imx->mmio_base + MX3_PWMCR);
+	do {
+		usleep_range(200, 1000);
+		cr = readl(imx->mmio_base + MX3_PWMCR);
+	} while ((cr & MX3_PWMCR_SWR) &&
+		 (wait_count++ < MX3_PWM_SWR_LOOP));
+
+	if (cr & MX3_PWMCR_SWR)
+		dev_warn(dev, "software reset timeout\n");
+}
+
+static void imx_pwm_wait_fifo_slot(struct pwm_chip *chip,
+				   struct pwm_device *pwm)
 {
 	struct imx_chip *imx = to_imx_chip(chip);
 	struct device *dev = chip->dev;
-	unsigned long long c;
-	unsigned long period_cycles, duty_cycles, prescale;
 	unsigned int period_ms;
-	bool enable = pwm_is_enabled(pwm);
-	int wait_count = 0, fifoav;
-	u32 cr, sr;
+	int fifoav;
+	u32 sr;
 
-	/*
-	 * i.MX PWMv2 has a 4-word sample FIFO.
-	 * In order to avoid FIFO overflow issue, we do software reset
-	 * to clear all sample FIFO if the controller is disabled or
-	 * wait for a full PWM cycle to get a relinquished FIFO slot
-	 * when the controller is enabled and the FIFO is fully loaded.
-	 */
-	if (enable) {
 	sr = readl(imx->mmio_base + MX3_PWMSR);
 	fifoav = sr & MX3_PWMSR_FIFOAV_MASK;
 	if (fifoav == MX3_PWMSR_FIFOAV_4WORDS) {
@@ -137,28 +154,32 @@ static int imx_pwm_config_v2(struct pwm_chip *chip,
 		if (fifoav == (sr & MX3_PWMSR_FIFOAV_MASK))
 			dev_warn(dev, "there is no free FIFO slot\n");
 	}
-	} else {
-		writel(MX3_PWMCR_SWR, imx->mmio_base + MX3_PWMCR);
-		do {
-			usleep_range(200, 1000);
-			cr = readl(imx->mmio_base + MX3_PWMCR);
-		} while ((cr & MX3_PWMCR_SWR) &&
-			 (wait_count++ < MX3_PWM_SWR_LOOP));
+}
 
-		if (cr & MX3_PWMCR_SWR)
-			dev_warn(dev, "software reset timeout\n");
-	}
+static int imx_pwm_apply_v2(struct pwm_chip *chip, struct pwm_device *pwm,
+			    struct pwm_state *state)
+{
+	unsigned long period_cycles, duty_cycles, prescale;
+	struct imx_chip *imx = to_imx_chip(chip);
+	struct pwm_state cstate;
+	unsigned long long c;
+	int ret;
+	u32 cr;
+
+	pwm_get_state(pwm, &cstate);
 
+	if (state->enabled) {
 		c = clk_get_rate(imx->clk_per);
-	c = c * period_ns;
+		c *= state->period;
+
 		do_div(c, 1000000000);
 		period_cycles = c;
 
 		prescale = period_cycles / 0x10000 + 1;
 
 		period_cycles /= prescale;
-	c = (unsigned long long)period_cycles * duty_ns;
-	do_div(c, period_ns);
+		c = (unsigned long long)period_cycles * state->duty_cycle;
+		do_div(c, state->period);
 		duty_cycles = c;
 
 		/*
@@ -170,97 +191,66 @@ static int imx_pwm_config_v2(struct pwm_chip *chip,
 		else
 			period_cycles = 0;
 
+		/*
+		 * Wait for a free FIFO slot if the PWM is already enabled, and
+		 * flush the FIFO if the PWM was disabled and is about to be
+		 * enabled.
+		 */
+		if (cstate.enabled) {
+			imx_pwm_wait_fifo_slot(chip, pwm);
+		} else {
+			ret = clk_prepare_enable(imx->clk_per);
+			if (ret)
+				return ret;
+
+			imx_pwm_sw_reset(chip);
+		}
+
 		writel(duty_cycles, imx->mmio_base + MX3_PWMSAR);
 		writel(period_cycles, imx->mmio_base + MX3_PWMPR);
 
 		cr = MX3_PWMCR_PRESCALER(prescale) |
 		     MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN |
-		MX3_PWMCR_DBGEN | MX3_PWMCR_CLKSRC_IPG_HIGH;
+		     MX3_PWMCR_DBGEN | MX3_PWMCR_CLKSRC_IPG_HIGH |
+		     MX3_PWMCR_EN;
 
-	if (enable)
-		cr |= MX3_PWMCR_EN;
+		if (state->polarity == PWM_POLARITY_INVERSED)
+			cr |= MX3_PWMCR_POUTC;
 
 		writel(cr, imx->mmio_base + MX3_PWMCR);
+	} else if (cstate.enabled) {
+		writel(0, imx->mmio_base + MX3_PWMCR);
 
-	return 0;
-}
-
-static void imx_pwm_set_enable_v2(struct pwm_chip *chip, bool enable)
-{
-	struct imx_chip *imx = to_imx_chip(chip);
-	u32 val;
-
-	val = readl(imx->mmio_base + MX3_PWMCR);
-
-	if (enable)
-		val |= MX3_PWMCR_EN;
-	else
-		val &= ~MX3_PWMCR_EN;
-
-	writel(val, imx->mmio_base + MX3_PWMCR);
-}
-
-static int imx_pwm_config(struct pwm_chip *chip,
-		struct pwm_device *pwm, int duty_ns, int period_ns)
-{
-	struct imx_chip *imx = to_imx_chip(chip);
-	int ret;
-
-	ret = clk_prepare_enable(imx->clk_ipg);
-	if (ret)
-		return ret;
-
-	ret = imx->config(chip, pwm, duty_ns, period_ns);
-
-	clk_disable_unprepare(imx->clk_ipg);
-
-	return ret;
-}
-
-static int imx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
-	struct imx_chip *imx = to_imx_chip(chip);
-	int ret;
-
-	ret = clk_prepare_enable(imx->clk_per);
-	if (ret)
-		return ret;
-
-	imx->set_enable(chip, true);
+		clk_disable_unprepare(imx->clk_per);
+	}
 
 	return 0;
 }
 
-static void imx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
-	struct imx_chip *imx = to_imx_chip(chip);
-
-	imx->set_enable(chip, false);
-
-	clk_disable_unprepare(imx->clk_per);
-}
+static const struct pwm_ops imx_pwm_ops_v1 = {
+	.enable = imx_pwm_enable_v1,
+	.disable = imx_pwm_disable_v1,
+	.config = imx_pwm_config_v1,
+	.owner = THIS_MODULE,
+};
 
-static struct pwm_ops imx_pwm_ops = {
-	.enable = imx_pwm_enable,
-	.disable = imx_pwm_disable,
-	.config = imx_pwm_config,
+static const struct pwm_ops imx_pwm_ops_v2 = {
+	.apply = imx_pwm_apply_v2,
 	.owner = THIS_MODULE,
 };
 
 struct imx_pwm_data {
-	int (*config)(struct pwm_chip *chip,
-		struct pwm_device *pwm, int duty_ns, int period_ns);
-	void (*set_enable)(struct pwm_chip *chip, bool enable);
+	bool polarity_supported;
+	const struct pwm_ops *ops;
 };
 
 static struct imx_pwm_data imx_pwm_data_v1 = {
-	.config = imx_pwm_config_v1,
-	.set_enable = imx_pwm_set_enable_v1,
+	.ops = &imx_pwm_ops_v1,
 };
 
 static struct imx_pwm_data imx_pwm_data_v2 = {
-	.config = imx_pwm_config_v2,
-	.set_enable = imx_pwm_set_enable_v2,
+	.polarity_supported = true,
+	.ops = &imx_pwm_ops_v2,
 };
 
 static const struct of_device_id imx_pwm_dt_ids[] = {
@@ -282,6 +272,8 @@ static int imx_pwm_probe(struct platform_device *pdev)
 	if (!of_id)
 		return -ENODEV;
 
+	data = of_id->data;
+
 	imx = devm_kzalloc(&pdev->dev, sizeof(*imx), GFP_KERNEL);
 	if (imx == NULL)
 		return -ENOMEM;
@@ -293,27 +285,22 @@ static int imx_pwm_probe(struct platform_device *pdev)
 		return PTR_ERR(imx->clk_per);
 	}
 
-	imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
-	if (IS_ERR(imx->clk_ipg)) {
-		dev_err(&pdev->dev, "getting ipg clock failed with %ld\n",
-				PTR_ERR(imx->clk_ipg));
-		return PTR_ERR(imx->clk_ipg);
-	}
-
-	imx->chip.ops = &imx_pwm_ops;
+	imx->chip.ops = data->ops;
 	imx->chip.dev = &pdev->dev;
 	imx->chip.base = -1;
 	imx->chip.npwm = 1;
 
+	if (data->polarity_supported) {
+		dev_dbg(&pdev->dev, "PWM supports output inversion\n");
+		imx->chip.of_xlate = of_pwm_xlate_with_flags;
+		imx->chip.of_pwm_n_cells = 3;
+	}
+
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	imx->mmio_base = devm_ioremap_resource(&pdev->dev, r);
 	if (IS_ERR(imx->mmio_base))
 		return PTR_ERR(imx->mmio_base);
 
-	data = of_id->data;
-	imx->config = data->config;
-	imx->set_enable = data->set_enable;
-
 	ret = pwmchip_add(&imx->chip);
 	if (ret < 0)
 		return ret;

drivers/pwm/pwm-lpss-pci.c

@@ -17,6 +17,27 @@
 
 #include "pwm-lpss.h"
 
+/* BayTrail */
+static const struct pwm_lpss_boardinfo pwm_lpss_byt_info = {
+	.clk_rate = 25000000,
+	.npwm = 1,
+	.base_unit_bits = 16,
+};
+
+/* Braswell */
+static const struct pwm_lpss_boardinfo pwm_lpss_bsw_info = {
+	.clk_rate = 19200000,
+	.npwm = 1,
+	.base_unit_bits = 16,
+};
+
+/* Broxton */
+static const struct pwm_lpss_boardinfo pwm_lpss_bxt_info = {
+	.clk_rate = 19200000,
+	.npwm = 4,
+	.base_unit_bits = 22,
+};
+
 static int pwm_lpss_probe_pci(struct pci_dev *pdev,
 			      const struct pci_device_id *id)
 {
@@ -80,6 +101,7 @@ static const struct pci_device_id pwm_lpss_pci_ids[] = {
 	{ PCI_VDEVICE(INTEL, 0x1ac8), (unsigned long)&pwm_lpss_bxt_info},
 	{ PCI_VDEVICE(INTEL, 0x2288), (unsigned long)&pwm_lpss_bsw_info},
 	{ PCI_VDEVICE(INTEL, 0x2289), (unsigned long)&pwm_lpss_bsw_info},
+	{ PCI_VDEVICE(INTEL, 0x31c8), (unsigned long)&pwm_lpss_bxt_info},
 	{ PCI_VDEVICE(INTEL, 0x5ac8), (unsigned long)&pwm_lpss_bxt_info},
 	{ },
 };

drivers/pwm/pwm-lpss-platform.c

@@ -18,6 +18,27 @@
 
 #include "pwm-lpss.h"
 
+/* BayTrail */
+static const struct pwm_lpss_boardinfo pwm_lpss_byt_info = {
+	.clk_rate = 25000000,
+	.npwm = 1,
+	.base_unit_bits = 16,
+};
+
+/* Braswell */
+static const struct pwm_lpss_boardinfo pwm_lpss_bsw_info = {
+	.clk_rate = 19200000,
+	.npwm = 1,
+	.base_unit_bits = 16,
+};
+
+/* Broxton */
+static const struct pwm_lpss_boardinfo pwm_lpss_bxt_info = {
+	.clk_rate = 19200000,
+	.npwm = 4,
+	.base_unit_bits = 22,
+};
+
 static int pwm_lpss_probe_platform(struct platform_device *pdev)
 {
 	const struct pwm_lpss_boardinfo *info;

drivers/pwm/pwm-lpss.c

@@ -15,6 +15,7 @@
 
 #include <linux/delay.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
@@ -37,30 +38,6 @@ struct pwm_lpss_chip {
 	const struct pwm_lpss_boardinfo *info;
 };
 
-/* BayTrail */
-const struct pwm_lpss_boardinfo pwm_lpss_byt_info = {
-	.clk_rate = 25000000,
-	.npwm = 1,
-	.base_unit_bits = 16,
-};
-EXPORT_SYMBOL_GPL(pwm_lpss_byt_info);
-
-/* Braswell */
-const struct pwm_lpss_boardinfo pwm_lpss_bsw_info = {
-	.clk_rate = 19200000,
-	.npwm = 1,
-	.base_unit_bits = 16,
-};
-EXPORT_SYMBOL_GPL(pwm_lpss_bsw_info);
-
-/* Broxton */
-const struct pwm_lpss_boardinfo pwm_lpss_bxt_info = {
-	.clk_rate = 19200000,
-	.npwm = 4,
-	.base_unit_bits = 22,
-};
-EXPORT_SYMBOL_GPL(pwm_lpss_bxt_info);
-
 static inline struct pwm_lpss_chip *to_lpwm(struct pwm_chip *chip)
 {
 	return container_of(chip, struct pwm_lpss_chip, chip);
@@ -80,17 +57,42 @@ static inline void pwm_lpss_write(const struct pwm_device *pwm, u32 value)
 	writel(value, lpwm->regs + pwm->hwpwm * PWM_SIZE + PWM);
 }
 
-static void pwm_lpss_update(struct pwm_device *pwm)
+static int pwm_lpss_update(struct pwm_device *pwm)
 {
+	struct pwm_lpss_chip *lpwm = to_lpwm(pwm->chip);
+	const void __iomem *addr = lpwm->regs + pwm->hwpwm * PWM_SIZE + PWM;
+	const unsigned int ms = 500 * USEC_PER_MSEC;
+	u32 val;
+	int err;
+
 	pwm_lpss_write(pwm, pwm_lpss_read(pwm) | PWM_SW_UPDATE);
-	/* Give it some time to propagate */
-	usleep_range(10, 50);
+
+	/*
+	 * PWM Configuration register has SW_UPDATE bit that is set when a new
+	 * configuration is written to the register. The bit is automatically
+	 * cleared at the start of the next output cycle by the IP block.
+	 *
+	 * If one writes a new configuration to the register while it still has
+	 * the bit enabled, PWM may freeze. That is, while one can still write
+	 * to the register, it won't have an effect. Thus, we try to sleep long
+	 * enough that the bit gets cleared and make sure the bit is not
+	 * enabled while we update the configuration.
+	 */
+	err = readl_poll_timeout(addr, val, !(val & PWM_SW_UPDATE), 40, ms);
+	if (err)
+		dev_err(pwm->chip->dev, "PWM_SW_UPDATE was not cleared\n");
+
+	return err;
+}
+
+static inline int pwm_lpss_is_updating(struct pwm_device *pwm)
+{
+	return (pwm_lpss_read(pwm) & PWM_SW_UPDATE) ? -EBUSY : 0;
 }
 
-static int pwm_lpss_config(struct pwm_chip *chip, struct pwm_device *pwm,
+static void pwm_lpss_prepare(struct pwm_lpss_chip *lpwm, struct pwm_device *pwm,
 			     int duty_ns, int period_ns)
 {
-	struct pwm_lpss_chip *lpwm = to_lpwm(chip);
 	unsigned long long on_time_div;
 	unsigned long c = lpwm->info->clk_rate, base_unit_range;
 	unsigned long long base_unit, freq = NSEC_PER_SEC;
@@ -102,62 +104,62 @@ static int pwm_lpss_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	 * The equation is:
 	 * base_unit = round(base_unit_range * freq / c)
 	 */
-	base_unit_range = BIT(lpwm->info->base_unit_bits);
+	base_unit_range = BIT(lpwm->info->base_unit_bits) - 1;
 	freq *= base_unit_range;
 
 	base_unit = DIV_ROUND_CLOSEST_ULL(freq, c);
 
-	if (duty_ns <= 0)
-		duty_ns = 1;
 	on_time_div = 255ULL * duty_ns;
 	do_div(on_time_div, period_ns);
 	on_time_div = 255ULL - on_time_div;
 
-	pm_runtime_get_sync(chip->dev);
-
 	ctrl = pwm_lpss_read(pwm);
 	ctrl &= ~PWM_ON_TIME_DIV_MASK;
-	ctrl &= ~((base_unit_range - 1) << PWM_BASE_UNIT_SHIFT);
-	base_unit &= (base_unit_range - 1);
+	ctrl &= ~(base_unit_range << PWM_BASE_UNIT_SHIFT);
+	base_unit &= base_unit_range;
 	ctrl |= (u32) base_unit << PWM_BASE_UNIT_SHIFT;
 	ctrl |= on_time_div;
 	pwm_lpss_write(pwm, ctrl);
-
-	/*
-	 * If the PWM is already enabled we need to notify the hardware
-	 * about the change by setting PWM_SW_UPDATE.
-	 */
-	if (pwm_is_enabled(pwm))
-		pwm_lpss_update(pwm);
-
-	pm_runtime_put(chip->dev);
-
-	return 0;
 }
 
-static int pwm_lpss_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+static int pwm_lpss_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			  struct pwm_state *state)
 {
-	pm_runtime_get_sync(chip->dev);
+	struct pwm_lpss_chip *lpwm = to_lpwm(chip);
+	int ret;
 
-	/*
-	 * Hardware must first see PWM_SW_UPDATE before the PWM can be
-	 * enabled.
-	 */
-	pwm_lpss_update(pwm);
+	if (state->enabled) {
+		if (!pwm_is_enabled(pwm)) {
+			pm_runtime_get_sync(chip->dev);
+			ret = pwm_lpss_is_updating(pwm);
+			if (ret) {
+				pm_runtime_put(chip->dev);
+				return ret;
+			}
+			pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period);
+			ret = pwm_lpss_update(pwm);
+			if (ret) {
+				pm_runtime_put(chip->dev);
+				return ret;
+			}
 			pwm_lpss_write(pwm, pwm_lpss_read(pwm) | PWM_ENABLE);
-	return 0;
-}
-
-static void pwm_lpss_disable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
+		} else {
+			ret = pwm_lpss_is_updating(pwm);
+			if (ret)
+				return ret;
+			pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period);
+			return pwm_lpss_update(pwm);
+		}
+	} else if (pwm_is_enabled(pwm)) {
 		pwm_lpss_write(pwm, pwm_lpss_read(pwm) & ~PWM_ENABLE);
 		pm_runtime_put(chip->dev);
+	}
+
+	return 0;
 }
 
 static const struct pwm_ops pwm_lpss_ops = {
-	.config = pwm_lpss_config,
-	.enable = pwm_lpss_enable,
-	.disable = pwm_lpss_disable,
+	.apply = pwm_lpss_apply,
 	.owner = THIS_MODULE,
 };
 

drivers/pwm/pwm-lpss.h

@@ -24,10 +24,6 @@ struct pwm_lpss_boardinfo {
 	unsigned long base_unit_bits;
 };
 
-extern const struct pwm_lpss_boardinfo pwm_lpss_byt_info;
-extern const struct pwm_lpss_boardinfo pwm_lpss_bsw_info;
-extern const struct pwm_lpss_boardinfo pwm_lpss_bxt_info;
-
 struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev, struct resource *r,
 				     const struct pwm_lpss_boardinfo *info);
 int pwm_lpss_remove(struct pwm_lpss_chip *lpwm);

drivers/pwm/pwm-pca9685.c

@@ -20,8 +20,10 @@
  */
 
 #include <linux/acpi.h>
+#include <linux/gpio/driver.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/platform_device.h>
 #include <linux/property.h>
 #include <linux/pwm.h>
@@ -65,7 +67,6 @@
 #define PCA9685_MAXCHAN		0x10
 
 #define LED_FULL		(1 << 4)
-#define MODE1_RESTART		(1 << 7)
 #define MODE1_SLEEP		(1 << 4)
 #define MODE2_INVRT		(1 << 4)
 #define MODE2_OUTDRV		(1 << 2)
@@ -81,6 +82,10 @@ struct pca9685 {
 	int active_cnt;
 	int duty_ns;
 	int period_ns;
+#if IS_ENABLED(CONFIG_GPIOLIB)
+	struct mutex lock;
+	struct gpio_chip gpio;
+#endif
 };
 
 static inline struct pca9685 *to_pca(struct pwm_chip *chip)
@@ -88,6 +93,151 @@ static inline struct pca9685 *to_pca(struct pwm_chip *chip)
 	return container_of(chip, struct pca9685, chip);
 }
 
+#if IS_ENABLED(CONFIG_GPIOLIB)
+static int pca9685_pwm_gpio_request(struct gpio_chip *gpio, unsigned int offset)
+{
+	struct pca9685 *pca = gpiochip_get_data(gpio);
+	struct pwm_device *pwm;
+
+	mutex_lock(&pca->lock);
+
+	pwm = &pca->chip.pwms[offset];
+
+	if (pwm->flags & (PWMF_REQUESTED | PWMF_EXPORTED)) {
+		mutex_unlock(&pca->lock);
+		return -EBUSY;
+	}
+
+	pwm_set_chip_data(pwm, (void *)1);
+
+	mutex_unlock(&pca->lock);
+	return 0;
+}
+
+static void pca9685_pwm_gpio_free(struct gpio_chip *gpio, unsigned int offset)
+{
+	struct pca9685 *pca = gpiochip_get_data(gpio);
+	struct pwm_device *pwm;
+
+	mutex_lock(&pca->lock);
+	pwm = &pca->chip.pwms[offset];
+	pwm_set_chip_data(pwm, NULL);
+	mutex_unlock(&pca->lock);
+}
+
+static bool pca9685_pwm_is_gpio(struct pca9685 *pca, struct pwm_device *pwm)
+{
+	bool is_gpio = false;
+
+	mutex_lock(&pca->lock);
+
+	if (pwm->hwpwm >= PCA9685_MAXCHAN) {
+		unsigned int i;
+
+		/*
+		 * Check if any of the GPIOs are requested and in that case
+		 * prevent using the "all LEDs" channel.
+		 */
+		for (i = 0; i < pca->gpio.ngpio; i++)
+			if (gpiochip_is_requested(&pca->gpio, i)) {
+				is_gpio = true;
+				break;
+			}
+	} else if (pwm_get_chip_data(pwm)) {
+		is_gpio = true;
+	}
+
+	mutex_unlock(&pca->lock);
+	return is_gpio;
+}
+
+static int pca9685_pwm_gpio_get(struct gpio_chip *gpio, unsigned int offset)
+{
+	struct pca9685 *pca = gpiochip_get_data(gpio);
+	struct pwm_device *pwm = &pca->chip.pwms[offset];
+	unsigned int value;
+
+	regmap_read(pca->regmap, LED_N_ON_H(pwm->hwpwm), &value);
+
+	return value & LED_FULL;
+}
+
+static void pca9685_pwm_gpio_set(struct gpio_chip *gpio, unsigned int offset,
+				 int value)
+{
+	struct pca9685 *pca = gpiochip_get_data(gpio);
+	struct pwm_device *pwm = &pca->chip.pwms[offset];
+	unsigned int on = value ? LED_FULL : 0;
+
+	/* Clear both OFF registers */
+	regmap_write(pca->regmap, LED_N_OFF_L(pwm->hwpwm), 0);
+	regmap_write(pca->regmap, LED_N_OFF_H(pwm->hwpwm), 0);
+
+	/* Set the full ON bit */
+	regmap_write(pca->regmap, LED_N_ON_H(pwm->hwpwm), on);
+}
+
+static int pca9685_pwm_gpio_get_direction(struct gpio_chip *chip,
+					  unsigned int offset)
+{
+	/* Always out */
+	return 0;
+}
+
+static int pca9685_pwm_gpio_direction_input(struct gpio_chip *gpio,
+					    unsigned int offset)
+{
+	return -EINVAL;
+}
+
+static int pca9685_pwm_gpio_direction_output(struct gpio_chip *gpio,
+					     unsigned int offset, int value)
+{
+	pca9685_pwm_gpio_set(gpio, offset, value);
+
+	return 0;
+}
+
+/*
+ * The PCA9685 has a bit for turning the PWM output full off or on. Some
+ * boards like Intel Galileo actually uses these as normal GPIOs so we
+ * expose a GPIO chip here which can exclusively take over the underlying
+ * PWM channel.
+ */
+static int pca9685_pwm_gpio_probe(struct pca9685 *pca)
+{
+	struct device *dev = pca->chip.dev;
+
+	mutex_init(&pca->lock);
+
+	pca->gpio.label = dev_name(dev);
+	pca->gpio.parent = dev;
+	pca->gpio.request = pca9685_pwm_gpio_request;
+	pca->gpio.free = pca9685_pwm_gpio_free;
+	pca->gpio.get_direction = pca9685_pwm_gpio_get_direction;
+	pca->gpio.direction_input = pca9685_pwm_gpio_direction_input;
+	pca->gpio.direction_output = pca9685_pwm_gpio_direction_output;
+	pca->gpio.get = pca9685_pwm_gpio_get;
+	pca->gpio.set = pca9685_pwm_gpio_set;
+	pca->gpio.base = -1;
+	pca->gpio.ngpio = PCA9685_MAXCHAN;
+	pca->gpio.can_sleep = true;
+
+	return devm_gpiochip_add_data(dev, &pca->gpio, pca);
+}
+#else
+static inline bool pca9685_pwm_is_gpio(struct pca9685 *pca,
+				       struct pwm_device *pwm)
+{
+	return false;
+}
+
+static inline int pca9685_pwm_gpio_probe(struct pca9685 *pca)
+{
+	return 0;
+}
+#endif
+
 static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 			      int duty_ns, int period_ns)
 {
@@ -117,16 +267,6 @@ static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 			udelay(500);
 
 			pca->period_ns = period_ns;
-
-			/*
-			 * If the duty cycle did not change, restart PWM with
-			 * the same duty cycle to period ratio and return.
-			 */
-			if (duty_ns == pca->duty_ns) {
-				regmap_update_bits(pca->regmap, PCA9685_MODE1,
-						   MODE1_RESTART, 0x1);
-				return 0;
-			}
 		} else {
 			dev_err(chip->dev,
 				"prescaler not set: period out of bounds!\n");
@@ -264,6 +404,9 @@ static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct pca9685 *pca = to_pca(chip);
 
+	if (pca9685_pwm_is_gpio(pca, pwm))
+		return -EBUSY;
+
 	if (pca->active_cnt++ == 0)
 		return regmap_update_bits(pca->regmap, PCA9685_MODE1,
 					  MODE1_SLEEP, 0x0);
@@ -344,7 +487,15 @@ static int pca9685_pwm_probe(struct i2c_client *client,
 	pca->chip.dev = &client->dev;
 	pca->chip.base = -1;
 
-	return pwmchip_add(&pca->chip);
+	ret = pwmchip_add(&pca->chip);
+	if (ret < 0)
+		return ret;
+
+	ret = pca9685_pwm_gpio_probe(pca);
+	if (ret < 0)
+		pwmchip_remove(&pca->chip);
+
+	return ret;
 }
 
 static int pca9685_pwm_remove(struct i2c_client *client)

drivers/pwm/pwm-pxa.c

@@ -118,7 +118,7 @@ static void pxa_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 	clk_disable_unprepare(pc->clk);
 }
 
-static struct pwm_ops pxa_pwm_ops = {
+static const struct pwm_ops pxa_pwm_ops = {
 	.config = pxa_pwm_config,
 	.enable = pxa_pwm_enable,
 	.disable = pxa_pwm_disable,

drivers/pwm/pwm-vt8500.c

@@ -184,7 +184,7 @@ static int vt8500_pwm_set_polarity(struct pwm_chip *chip,
 	return 0;
 }
 
-static struct pwm_ops vt8500_pwm_ops = {
+static const struct pwm_ops vt8500_pwm_ops = {
 	.enable = vt8500_pwm_enable,
 	.disable = vt8500_pwm_disable,
 	.config = vt8500_pwm_config,