Merge tag 'pwm/for-3.20-rc1' of git://git.kernel.org/pub/scm/linux/ke…

…rnel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "This contains two new drivers, one for Allwinner SoCs and the other
  for Imagination Technologies' Pistachio SoC.

  Complementing this are a couple of fixes to the Atmel HLCDC PWM and
  STi PWM drivers as well as minor cleanups to the core and the Tegra
  driver"

* tag 'pwm/for-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm:
  pwm: tegra: Use NSEC_PER_SEC
  pwm: Remove unnecessary check before of_node_put()
  pwm: Add device tree binding document for IMG PWM DAC
  pwm: Imagination Technologies PWM DAC driver
  pwm: sti: Maintain a bitmap of configured devices
  pwm: sunxi: document OF bindings
  pwm: Add Allwinner SoC support
  pwm: atmel-hlcdc: Prevent division by zero
  pwm: atmel-hlcdc: Depend on HAVE_CLK

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

@@ -0,0 +1,24 @@
+*Imagination Technologies PWM DAC driver
+
+Required properties:
+  - compatible: Should be "img,pistachio-pwm"
+  - reg: Should contain physical base address and length of pwm registers.
+  - clocks: Must contain an entry for each entry in clock-names.
+	See ../clock/clock-bindings.txt for details.
+  - clock-names: Must include the following entries.
+    - pwm: PWM operating clock.
+    - sys: PWM system interface clock.
+  - #pwm-cells: Should be 2. See pwm.txt in this directory for the
+	description of the cells format.
+  - img,cr-periph: Must contain a phandle to the peripheral control
+	syscon node which contains PWM control registers.
+
+Example:
+	pwm: pwm@18101300 {
+		compatible = "img,pistachio-pwm";
+		reg = <0x18101300 0x100>;
+		clocks = <&pwm_clk>, <&system_clk>;
+		clock-names = "pwm", "sys";
+		#pwm-cells = <2>;
+		img,cr-periph = <&cr_periph>;
+	};

Documentation/devicetree/bindings/pwm/pwm-sun4i.txt

@@ -0,0 +1,20 @@
+Allwinner sun4i and sun7i SoC PWM controller
+
+Required properties:
+  - compatible: should be one of:
+    - "allwinner,sun4i-a10-pwm"
+    - "allwinner,sun7i-a20-pwm"
+  - reg: physical base address and length of the controller's registers
+  - #pwm-cells: should be 3. See pwm.txt in this directory for a description of
+    the cells format.
+  - clocks: From common clock binding, handle to the parent clock.
+
+Example:
+
+	pwm: pwm@01c20e00 {
+		compatible = "allwinner,sun7i-a20-pwm";
+		reg = <0x01c20e00 0xc>;
+		clocks = <&osc24M>;
+		#pwm-cells = <3>;
+		status = "disabled";
+	};

drivers/pwm/Kconfig

@@ -53,6 +53,7 @@ config PWM_ATMEL
 config PWM_ATMEL_HLCDC_PWM
 	tristate "Atmel HLCDC PWM support"
 	depends on MFD_ATMEL_HLCDC
+	depends on HAVE_CLK
 	help
 	  Generic PWM framework driver for the PWM output of the HLCDC
 	  (Atmel High-end LCD Controller). This PWM output is mainly used
@@ -130,6 +131,19 @@ config PWM_FSL_FTM
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-fsl-ftm.
 
+config PWM_IMG
+	tristate "Imagination Technologies PWM driver"
+	depends on HAS_IOMEM
+	depends on MFD_SYSCON
+	depends on COMMON_CLK
+	depends on MIPS || COMPILE_TEST
+	help
+	  Generic PWM framework driver for Imagination Technologies
+	  PWM block which supports 4 channels.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-img
+
 config PWM_IMX
 	tristate "i.MX PWM support"
 	depends on ARCH_MXC
@@ -283,6 +297,16 @@ config PWM_STI
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-sti.
 
+config PWM_SUN4I
+	tristate "Allwinner PWM support"
+	depends on ARCH_SUNXI || COMPILE_TEST
+	depends on HAS_IOMEM && COMMON_CLK
+	help
+	  Generic PWM framework driver for Allwinner SoCs.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-sun4i.
+
 config PWM_TEGRA
 	tristate "NVIDIA Tegra PWM support"
 	depends on ARCH_TEGRA

drivers/pwm/Makefile

@@ -10,6 +10,7 @@ obj-$(CONFIG_PWM_BFIN)		+= pwm-bfin.o
 obj-$(CONFIG_PWM_CLPS711X)	+= pwm-clps711x.o
 obj-$(CONFIG_PWM_EP93XX)	+= pwm-ep93xx.o
 obj-$(CONFIG_PWM_FSL_FTM)	+= pwm-fsl-ftm.o
+obj-$(CONFIG_PWM_IMG)		+= pwm-img.o
 obj-$(CONFIG_PWM_IMX)		+= pwm-imx.o
 obj-$(CONFIG_PWM_JZ4740)	+= pwm-jz4740.o
 obj-$(CONFIG_PWM_LP3943)	+= pwm-lp3943.o
@@ -26,6 +27,7 @@ obj-$(CONFIG_PWM_ROCKCHIP)	+= pwm-rockchip.o
 obj-$(CONFIG_PWM_SAMSUNG)	+= pwm-samsung.o
 obj-$(CONFIG_PWM_SPEAR)		+= pwm-spear.o
 obj-$(CONFIG_PWM_STI)		+= pwm-sti.o
+obj-$(CONFIG_PWM_SUN4I)		+= pwm-sun4i.o
 obj-$(CONFIG_PWM_TEGRA)		+= pwm-tegra.o
 obj-$(CONFIG_PWM_TIECAP)	+= pwm-tiecap.o
 obj-$(CONFIG_PWM_TIEHRPWM)	+= pwm-tiehrpwm.o

drivers/pwm/core.c

@@ -192,7 +192,7 @@ static void of_pwmchip_add(struct pwm_chip *chip)
 
 static void of_pwmchip_remove(struct pwm_chip *chip)
 {
-	if (chip->dev && chip->dev->of_node)
+	if (chip->dev)
 		of_node_put(chip->dev->of_node);
 }
 

drivers/pwm/pwm-atmel-hlcdc.c

@@ -64,6 +64,9 @@ static int atmel_hlcdc_pwm_config(struct pwm_chip *c,
 
 	if (!chip->errata || !chip->errata->slow_clk_erratum) {
 		clk_freq = clk_get_rate(new_clk);
+		if (!clk_freq)
+			return -EINVAL;
+
 		clk_period_ns = (u64)NSEC_PER_SEC * 256;
 		do_div(clk_period_ns, clk_freq);
 	}
@@ -73,6 +76,9 @@ static int atmel_hlcdc_pwm_config(struct pwm_chip *c,
 	    clk_period_ns > period_ns) {
 		new_clk = hlcdc->sys_clk;
 		clk_freq = clk_get_rate(new_clk);
+		if (!clk_freq)
+			return -EINVAL;
+
 		clk_period_ns = (u64)NSEC_PER_SEC * 256;
 		do_div(clk_period_ns, clk_freq);
 	}

drivers/pwm/pwm-img.c

@@ -0,0 +1,249 @@
+/*
+ * Imagination Technologies Pulse Width Modulator driver
+ *
+ * Copyright (c) 2014-2015, Imagination Technologies
+ *
+ * Based on drivers/pwm/pwm-tegra.c, Copyright (c) 2010, NVIDIA Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License.
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+/* PWM registers */
+#define PWM_CTRL_CFG				0x0000
+#define PWM_CTRL_CFG_NO_SUB_DIV			0
+#define PWM_CTRL_CFG_SUB_DIV0			1
+#define PWM_CTRL_CFG_SUB_DIV1			2
+#define PWM_CTRL_CFG_SUB_DIV0_DIV1		3
+#define PWM_CTRL_CFG_DIV_SHIFT(ch)		((ch) * 2 + 4)
+#define PWM_CTRL_CFG_DIV_MASK			0x3
+
+#define PWM_CH_CFG(ch)				(0x4 + (ch) * 4)
+#define PWM_CH_CFG_TMBASE_SHIFT			0
+#define PWM_CH_CFG_DUTY_SHIFT			16
+
+#define PERIP_PWM_PDM_CONTROL			0x0140
+#define PERIP_PWM_PDM_CONTROL_CH_MASK		0x1
+#define PERIP_PWM_PDM_CONTROL_CH_SHIFT(ch)	((ch) * 4)
+
+#define MAX_TMBASE_STEPS			65536
+
+struct img_pwm_chip {
+	struct device	*dev;
+	struct pwm_chip	chip;
+	struct clk	*pwm_clk;
+	struct clk	*sys_clk;
+	void __iomem	*base;
+	struct regmap	*periph_regs;
+};
+
+static inline struct img_pwm_chip *to_img_pwm_chip(struct pwm_chip *chip)
+{
+	return container_of(chip, struct img_pwm_chip, chip);
+}
+
+static inline void img_pwm_writel(struct img_pwm_chip *chip,
+				  u32 reg, u32 val)
+{
+	writel(val, chip->base + reg);
+}
+
+static inline u32 img_pwm_readl(struct img_pwm_chip *chip,
+					 u32 reg)
+{
+	return readl(chip->base + reg);
+}
+
+static int img_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+			  int duty_ns, int period_ns)
+{
+	u32 val, div, duty, timebase;
+	unsigned long mul, output_clk_hz, input_clk_hz;
+	struct img_pwm_chip *pwm_chip = to_img_pwm_chip(chip);
+
+	input_clk_hz = clk_get_rate(pwm_chip->pwm_clk);
+	output_clk_hz = DIV_ROUND_UP(NSEC_PER_SEC, period_ns);
+
+	mul = DIV_ROUND_UP(input_clk_hz, output_clk_hz);
+	if (mul <= MAX_TMBASE_STEPS) {
+		div = PWM_CTRL_CFG_NO_SUB_DIV;
+		timebase = DIV_ROUND_UP(mul, 1);
+	} else if (mul <= MAX_TMBASE_STEPS * 8) {
+		div = PWM_CTRL_CFG_SUB_DIV0;
+		timebase = DIV_ROUND_UP(mul, 8);
+	} else if (mul <= MAX_TMBASE_STEPS * 64) {
+		div = PWM_CTRL_CFG_SUB_DIV1;
+		timebase = DIV_ROUND_UP(mul, 64);
+	} else if (mul <= MAX_TMBASE_STEPS * 512) {
+		div = PWM_CTRL_CFG_SUB_DIV0_DIV1;
+		timebase = DIV_ROUND_UP(mul, 512);
+	} else if (mul > MAX_TMBASE_STEPS * 512) {
+		dev_err(chip->dev,
+			"failed to configure timebase steps/divider value\n");
+		return -EINVAL;
+	}
+
+	duty = DIV_ROUND_UP(timebase * duty_ns, period_ns);
+
+	val = img_pwm_readl(pwm_chip, PWM_CTRL_CFG);
+	val &= ~(PWM_CTRL_CFG_DIV_MASK << PWM_CTRL_CFG_DIV_SHIFT(pwm->hwpwm));
+	val |= (div & PWM_CTRL_CFG_DIV_MASK) <<
+		PWM_CTRL_CFG_DIV_SHIFT(pwm->hwpwm);
+	img_pwm_writel(pwm_chip, PWM_CTRL_CFG, val);
+
+	val = (duty << PWM_CH_CFG_DUTY_SHIFT) |
+	      (timebase << PWM_CH_CFG_TMBASE_SHIFT);
+	img_pwm_writel(pwm_chip, PWM_CH_CFG(pwm->hwpwm), val);
+
+	return 0;
+}
+
+static int img_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	u32 val;
+	struct img_pwm_chip *pwm_chip = to_img_pwm_chip(chip);
+
+	val = img_pwm_readl(pwm_chip, PWM_CTRL_CFG);
+	val |= BIT(pwm->hwpwm);
+	img_pwm_writel(pwm_chip, PWM_CTRL_CFG, val);
+
+	regmap_update_bits(pwm_chip->periph_regs, PERIP_PWM_PDM_CONTROL,
+			   PERIP_PWM_PDM_CONTROL_CH_MASK <<
+			   PERIP_PWM_PDM_CONTROL_CH_SHIFT(pwm->hwpwm), 0);
+
+	return 0;
+}
+
+static void img_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	u32 val;
+	struct img_pwm_chip *pwm_chip = to_img_pwm_chip(chip);
+
+	val = img_pwm_readl(pwm_chip, PWM_CTRL_CFG);
+	val &= ~BIT(pwm->hwpwm);
+	img_pwm_writel(pwm_chip, PWM_CTRL_CFG, val);
+}
+
+static const struct pwm_ops img_pwm_ops = {
+	.config = img_pwm_config,
+	.enable = img_pwm_enable,
+	.disable = img_pwm_disable,
+	.owner = THIS_MODULE,
+};
+
+static int img_pwm_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct resource *res;
+	struct img_pwm_chip *pwm;
+
+	pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
+	if (!pwm)
+		return -ENOMEM;
+
+	pwm->dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	pwm->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(pwm->base))
+		return PTR_ERR(pwm->base);
+
+	pwm->periph_regs = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
+							   "img,cr-periph");
+	if (IS_ERR(pwm->periph_regs))
+		return PTR_ERR(pwm->periph_regs);
+
+	pwm->sys_clk = devm_clk_get(&pdev->dev, "sys");
+	if (IS_ERR(pwm->sys_clk)) {
+		dev_err(&pdev->dev, "failed to get system clock\n");
+		return PTR_ERR(pwm->sys_clk);
+	}
+
+	pwm->pwm_clk = devm_clk_get(&pdev->dev, "pwm");
+	if (IS_ERR(pwm->pwm_clk)) {
+		dev_err(&pdev->dev, "failed to get pwm clock\n");
+		return PTR_ERR(pwm->pwm_clk);
+	}
+
+	ret = clk_prepare_enable(pwm->sys_clk);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "could not prepare or enable sys clock\n");
+		return ret;
+	}
+
+	ret = clk_prepare_enable(pwm->pwm_clk);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "could not prepare or enable pwm clock\n");
+		goto disable_sysclk;
+	}
+
+	pwm->chip.dev = &pdev->dev;
+	pwm->chip.ops = &img_pwm_ops;
+	pwm->chip.base = -1;
+	pwm->chip.npwm = 4;
+
+	ret = pwmchip_add(&pwm->chip);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "pwmchip_add failed: %d\n", ret);
+		goto disable_pwmclk;
+	}
+
+	platform_set_drvdata(pdev, pwm);
+	return 0;
+
+disable_pwmclk:
+	clk_disable_unprepare(pwm->pwm_clk);
+disable_sysclk:
+	clk_disable_unprepare(pwm->sys_clk);
+	return ret;
+}
+
+static int img_pwm_remove(struct platform_device *pdev)
+{
+	struct img_pwm_chip *pwm_chip = platform_get_drvdata(pdev);
+	u32 val;
+	unsigned int i;
+
+	for (i = 0; i < pwm_chip->chip.npwm; i++) {
+		val = img_pwm_readl(pwm_chip, PWM_CTRL_CFG);
+		val &= ~BIT(i);
+		img_pwm_writel(pwm_chip, PWM_CTRL_CFG, val);
+	}
+
+	clk_disable_unprepare(pwm_chip->pwm_clk);
+	clk_disable_unprepare(pwm_chip->sys_clk);
+
+	return pwmchip_remove(&pwm_chip->chip);
+}
+
+static const struct of_device_id img_pwm_of_match[] = {
+	{ .compatible = "img,pistachio-pwm", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, img_pwm_of_match);
+
+static struct platform_driver img_pwm_driver = {
+	.driver = {
+		.name = "img-pwm",
+		.of_match_table = img_pwm_of_match,
+	},
+	.probe = img_pwm_probe,
+	.remove = img_pwm_remove,
+};
+module_platform_driver(img_pwm_driver);
+
+MODULE_AUTHOR("Sai Masarapu <[email protected]>");
+MODULE_DESCRIPTION("Imagination Technologies PWM DAC driver");
+MODULE_LICENSE("GPL v2");