pwm: Move PUV3 PWM driver to PWM framework

This commit moves the driver to drivers/pwm and converts it to the new
PWM framework.
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Tested-by: Qin Rui <qinrui@mprc.pku.edu.cn>
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn>

arch/unicore32/Kconfig

@@ -20,9 +20,6 @@ config UNICORE32
 	  designs licensed by PKUnity Ltd.
 	  Please see web page at <http://www.pkunity.com/>.
 
-config HAVE_PWM
-	bool
-
 config GENERIC_GPIO
 	def_bool y
 
@@ -105,7 +102,8 @@ config PUV3_DB0913
 
 config PUV3_NB0916
 	bool "NetBook board (0916)"
-	select HAVE_PWM
+	select PWM
+	select PWM_PUV3
 
 config PUV3_SMW0919
 	bool "Security Mini-Workstation board (0919)"
@@ -219,12 +217,6 @@ config PUV3_GPIO
 	select GPIO_SYSFS if EXPERIMENTAL
 	default y
 
-config PUV3_PWM
-	tristate
-	default BACKLIGHT_PWM
-	help
-	  Enable support for NB0916 PWM controllers
-
 if PUV3_NB0916
 
 menu "PKUnity NetBook-0916 Features"

arch/unicore32/kernel/Makefile

@@ -16,7 +16,6 @@ obj-$(CONFIG_UNICORE_FPU_F64)	+= fpu-ucf64.o
 obj-$(CONFIG_ARCH_PUV3)		+= clock.o irq.o time.o
 
 obj-$(CONFIG_PUV3_GPIO)		+= gpio.o
-obj-$(CONFIG_PUV3_PWM)		+= pwm.o
 obj-$(CONFIG_PUV3_PM)		+= pm.o sleep.o
 obj-$(CONFIG_HIBERNATION)	+= hibernate.o hibernate_asm.o
 

drivers/pwm/Kconfig

 menuconfig PWM
 	bool "Pulse-Width Modulation (PWM) Support"
-	depends on !MACH_JZ4740 && !PUV3_PWM
+	depends on !MACH_JZ4740
 	help
 	  Generic Pulse-Width Modulation (PWM) support.
 
@@ -76,6 +76,15 @@ config PWM_MXS
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-mxs.
 
+config PWM_PUV3
+	tristate "PKUnity NetBook-0916 PWM support"
+	depends on ARCH_PUV3
+	help
+	  Generic PWM framework driver for PKUnity NetBook-0916.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-puv3.
+
 config PWM_PXA
 	tristate "PXA PWM support"
 	depends on ARCH_PXA

drivers/pwm/Makefile

@@ -4,6 +4,7 @@ obj-$(CONFIG_PWM_BFIN)		+= pwm-bfin.o
 obj-$(CONFIG_PWM_IMX)		+= pwm-imx.o
 obj-$(CONFIG_PWM_LPC32XX)	+= pwm-lpc32xx.o
 obj-$(CONFIG_PWM_MXS)		+= pwm-mxs.o
+obj-$(CONFIG_PWM_PUV3)		+= pwm-puv3.o
 obj-$(CONFIG_PWM_PXA)		+= pwm-pxa.o
 obj-$(CONFIG_PWM_SAMSUNG)	+= pwm-samsung.o
 obj-$(CONFIG_PWM_TEGRA)		+= pwm-tegra.o

arch/unicore32/kernel/pwm.c → drivers/pwm/pwm-puv3.c

@@ -23,39 +23,37 @@
 #include <asm/div64.h>
 #include <mach/hardware.h>
 
-struct pwm_device {
-	struct list_head	node;
-	struct platform_device *pdev;
-
+struct puv3_pwm_chip {
+	struct pwm_chip chip;
 	void __iomem *base;
-
-	const char	*label;
 	struct clk *clk;
-	int		clk_enabled;
-
-	unsigned int	use_count;
-	unsigned int	pwm_id;
+	bool enabled;
 };
 
+static inline struct puv3_pwm_chip *to_puv3(struct pwm_chip *chip)
+{
+	return container_of(chip, struct puv3_pwm_chip, chip);
+}
+
 /*
  * period_ns = 10^9 * (PRESCALE + 1) * (PV + 1) / PWM_CLK_RATE
  * duty_ns   = 10^9 * (PRESCALE + 1) * DC / PWM_CLK_RATE
  */
-int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
+static int puv3_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+			   int duty_ns, int period_ns)
 {
-	unsigned long long c;
 	unsigned long period_cycles, prescale, pv, dc;
+	struct puv3_pwm_chip *puv3 = to_puv3(chip);
+	unsigned long long c;
 
-	if (pwm == NULL || period_ns == 0 || duty_ns > period_ns)
-		return -EINVAL;
-
-	c = clk_get_rate(pwm->clk);
+	c = clk_get_rate(puv3->clk);
 	c = c * period_ns;
 	do_div(c, 1000000000);
 	period_cycles = c;
 
 	if (period_cycles < 1)
 		period_cycles = 1;
+
 	prescale = (period_cycles - 1) / 1024;
 	pv = period_cycles / (prescale + 1) - 1;
 
@@ -67,115 +65,57 @@ int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
 	else
 		dc = (pv + 1) * duty_ns / period_ns;
 
-	/* NOTE: the clock to PWM has to be enabled first
+	/*
+	 * NOTE: the clock to PWM has to be enabled first
 	 * before writing to the registers
 	 */
-	clk_enable(pwm->clk);
+	clk_prepare_enable(puv3->clk);
 
-	writel(prescale, pwm->base + OST_PWM_PWCR);
-	writel(pv - dc, pwm->base + OST_PWM_DCCR);
-	writel(pv, pwm->base + OST_PWM_PCR);
+	writel(prescale, puv3->base + OST_PWM_PWCR);
+	writel(pv - dc, puv3->base + OST_PWM_DCCR);
+	writel(pv, puv3->base + OST_PWM_PCR);
 
-	clk_disable(pwm->clk);
+	clk_disable_unprepare(puv3->clk);
 
 	return 0;
 }
-EXPORT_SYMBOL(pwm_config);
-
-int pwm_enable(struct pwm_device *pwm)
-{
-	int rc = 0;
-
-	if (!pwm->clk_enabled) {
-		rc = clk_enable(pwm->clk);
-		if (!rc)
-			pwm->clk_enabled = 1;
-	}
-	return rc;
-}
-EXPORT_SYMBOL(pwm_enable);
-
-void pwm_disable(struct pwm_device *pwm)
-{
-	if (pwm->clk_enabled) {
-		clk_disable(pwm->clk);
-		pwm->clk_enabled = 0;
-	}
-}
-EXPORT_SYMBOL(pwm_disable);
-
-static DEFINE_MUTEX(pwm_lock);
-static LIST_HEAD(pwm_list);
 
-struct pwm_device *pwm_request(int pwm_id, const char *label)
+static int puv3_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
-	struct pwm_device *pwm;
-	int found = 0;
-
-	mutex_lock(&pwm_lock);
-
-	list_for_each_entry(pwm, &pwm_list, node) {
-		if (pwm->pwm_id == pwm_id) {
-			found = 1;
-			break;
-		}
-	}
+	struct puv3_pwm_chip *puv3 = to_puv3(chip);
 
-	if (found) {
-		if (pwm->use_count == 0) {
-			pwm->use_count++;
-			pwm->label = label;
-		} else
-			pwm = ERR_PTR(-EBUSY);
-	} else
-		pwm = ERR_PTR(-ENOENT);
-
-	mutex_unlock(&pwm_lock);
-	return pwm;
+	return clk_prepare_enable(puv3->clk);
 }
-EXPORT_SYMBOL(pwm_request);
 
-void pwm_free(struct pwm_device *pwm)
+static void puv3_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
-	mutex_lock(&pwm_lock);
-
-	if (pwm->use_count) {
-		pwm->use_count--;
-		pwm->label = NULL;
-	} else
-		pr_warning("PWM device already freed\n");
+	struct puv3_pwm_chip *puv3 = to_puv3(chip);
 
-	mutex_unlock(&pwm_lock);
+	clk_disable_unprepare(puv3->clk);
 }
-EXPORT_SYMBOL(pwm_free);
 
-static inline void __add_pwm(struct pwm_device *pwm)
-{
-	mutex_lock(&pwm_lock);
-	list_add_tail(&pwm->node, &pwm_list);
-	mutex_unlock(&pwm_lock);
-}
+static const struct pwm_ops puv3_pwm_ops = {
+	.config = puv3_pwm_config,
+	.enable = puv3_pwm_enable,
+	.disable = puv3_pwm_disable,
+	.owner = THIS_MODULE,
+};
 
 static int __devinit pwm_probe(struct platform_device *pdev)
 {
-	struct pwm_device *pwm;
+	struct puv3_pwm_chip *puv3;
 	struct resource *r;
+	int ret;
 
-	pwm = devm_kzalloc(&pdev->dev, sizeof(struct pwm_device), GFP_KERNEL);
-	if (pwm == NULL) {
+	puv3 = devm_kzalloc(&pdev->dev, sizeof(*puv3), GFP_KERNEL);
+	if (puv3 == NULL) {
 		dev_err(&pdev->dev, "failed to allocate memory\n");
 		return -ENOMEM;
 	}
 
-	pwm->clk = devm_clk_get(&pdev->dev, "OST_CLK");
-	if (IS_ERR(pwm->clk))
-		return PTR_ERR(pwm->clk);
-
-	pwm->clk_enabled = 0;
-
-	pwm->use_count = 0;
-	pwm->pwm_id = pdev->id;
-	pwm->pdev = pdev;
+	puv3->clk = devm_clk_get(&pdev->dev, "OST_CLK");
+	if (IS_ERR(puv3->clk))
+		return PTR_ERR(puv3->clk);
 
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (r == NULL) {
@@ -183,28 +123,30 @@ static int __devinit pwm_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
-	pwm->base = devm_request_and_ioremap(&pdev->dev, r);
-	if (pwm->base == NULL)
+	puv3->base = devm_request_and_ioremap(&pdev->dev, r);
+	if (puv3->base == NULL)
 		return -EADDRNOTAVAIL;
 
-	__add_pwm(pwm);
-	platform_set_drvdata(pdev, pwm);
+	puv3->chip.dev = &pdev->dev;
+	puv3->chip.ops = &puv3_pwm_ops;
+	puv3->chip.base = -1;
+	puv3->chip.npwm = 1;
+
+	ret = pwmchip_add(&puv3->chip);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, puv3);
 	return 0;
 }
 
 static int __devexit pwm_remove(struct platform_device *pdev)
 {
-	struct pwm_device *pwm;
+	struct puv3_pwm_chip *puv3 = platform_get_drvdata(pdev);
 
-	pwm = platform_get_drvdata(pdev);
-	if (pwm == NULL)
-		return -ENODEV;
-
-	mutex_lock(&pwm_lock);
-	list_del(&pwm->node);
-	mutex_unlock(&pwm_lock);
-
-	return 0;
+	return pwmchip_remove(&puv3->chip);
 }
 
 static struct platform_driver puv3_pwm_driver = {