pwm: add hi3620 support

Support pwm driver of Hisilicon Hi3620 SoC.

Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>

3 files changed, 196 insertions, 0 deletions

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index e513cd99817..8ffb7c56e18 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -46,6 +46,15 @@ config PWM_BFIN
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-bfin.
 
+config PWM_HI3620
+	tristate "Hi3620 PWM support"
+	depends on ARCH_HS
+	help
+	  Generic PWM framework driver for Hisilicon Hi3620 SoC.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-hi3620.
+
 config PWM_IMX
 	tristate "i.MX pwm support"
 	depends on ARCH_MXC
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index 62a2963cfe5..076bdeb3965 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -1,6 +1,7 @@
 obj-$(CONFIG_PWM)		+= core.o
 obj-$(CONFIG_PWM_AB8500)	+= pwm-ab8500.o
 obj-$(CONFIG_PWM_BFIN)		+= pwm-bfin.o
+obj-$(CONFIG_PWM_HI3620)	+= pwm-hi3620.o
 obj-$(CONFIG_PWM_IMX)		+= pwm-imx.o
 obj-$(CONFIG_PWM_JZ4740)	+= pwm-jz4740.o
 obj-$(CONFIG_PWM_LPC32XX)	+= pwm-lpc32xx.o
diff --git a/drivers/pwm/pwm-hi3620.c b/drivers/pwm/pwm-hi3620.c
new file mode 100644
index 00000000000..1fbb6855cc0
--- /dev/null
+++ b/drivers/pwm/pwm-hi3620.c
@@ -0,0 +1,186 @@
+/*
+ * Hisilicon Hi3620 PWM driver
+ *
+ * Copyright (C) 2013 Hisilicon Ltd.
+ * Copyright (C) 2013 Linaro Ltd.
+ *
+ * Author: Haojian Zhuang <haojian.zhuang@linaro.org>
+ *
+ * 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, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/pwm.h>
+#include <linux/of_device.h>
+#include <linux/pinctrl/consumer.h>
+
+#define REG_OUT_EN			0x00
+#define REG_OUT_DIV			0x08
+#define REG_OUT_WIDE			0x10
+#define REG_OUT_WARN			0x18
+
+#define DELTA_NS			5
+
+struct hi3620_pwm_info {
+	struct pwm_chip		chip;
+	struct clk		*clk;
+	void __iomem		*mmio_base;
+	unsigned int		clk_rate;
+	int			ratio;
+};
+
+static inline struct hi3620_pwm_info *to_hi3620_pwm_info(struct pwm_chip *chip)
+{
+	return container_of(chip, struct hi3620_pwm_info, chip);
+}
+
+static int hi3620_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+			     int duty_ns, int period_ns)
+{
+	struct hi3620_pwm_info *info = to_hi3620_pwm_info(chip);
+	int ratio, data;
+	unsigned long long int c;
+
+	if (!info->ratio) {
+		c = (unsigned long long int)period_ns * info->clk_rate;
+		do_div(c, NSEC_PER_SEC);
+		ratio = (int)c;
+		info->ratio = 1 << __fls(ratio);
+		writel_relaxed(info->ratio, info->mmio_base + REG_OUT_DIV);
+		readl_relaxed(info->mmio_base + REG_OUT_DIV);
+	}
+	c = (unsigned long long int)(duty_ns + DELTA_NS)* info->clk_rate;
+	do_div(c, NSEC_PER_SEC);
+	data = (int)c;
+	writel_relaxed(data, info->mmio_base + REG_OUT_WIDE);
+	readl_relaxed(info->mmio_base + REG_OUT_WIDE);
+	return 0;
+}
+
+static int hi3620_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct hi3620_pwm_info *info = to_hi3620_pwm_info(chip);
+
+	writel_relaxed(1, info->mmio_base + REG_OUT_EN);
+	readl_relaxed(info->mmio_base + REG_OUT_EN);
+	return 0;
+}
+
+static void hi3620_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct hi3620_pwm_info *info = to_hi3620_pwm_info(chip);
+
+	writel_relaxed(0, info->mmio_base + REG_OUT_EN);
+	readl_relaxed(info->mmio_base + REG_OUT_EN);
+}
+
+static const struct pwm_ops hi3620_pwm_ops = {
+	.config		= hi3620_pwm_config,
+	.enable		= hi3620_pwm_enable,
+	.disable	= hi3620_pwm_disable,
+	.owner		= THIS_MODULE,
+};
+
+static int hi3620_pwm_probe(struct platform_device *pdev)
+{
+	struct pinctrl *pinctrl;
+	struct resource *res;
+	struct hi3620_pwm_info *info;
+	int ret;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "no memory resource defined\n");
+		return -ENODEV;
+	}
+
+	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
+	if (IS_ERR(pinctrl)) {
+		dev_err(&pdev->dev, "unable to select pin group\n");
+		return PTR_ERR(pinctrl);
+	}
+
+	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
+	if (!info) {
+		dev_err(&pdev->dev, "failed to allocate memory\n");
+		return -ENOMEM;
+	}
+	info->mmio_base = devm_request_and_ioremap(&pdev->dev, res);
+	if (!info->mmio_base)
+		return -EADDRNOTAVAIL;
+
+	info->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(info->clk)) {
+		dev_err(&pdev->dev, "failed to get clock\n");
+		return PTR_ERR(info->clk);
+	}
+	ret = clk_prepare_enable(info->clk);
+	if (ret)
+		return ret;
+	info->clk_rate = clk_get_rate(info->clk);
+	if (!info->clk_rate) {
+		dev_err(&pdev->dev, "failed to get clock rate\n");
+		return -EINVAL;
+	}
+	info->chip.dev = &pdev->dev;
+	info->chip.ops = &hi3620_pwm_ops;
+	info->chip.base = -1;
+	info->chip.npwm = 1;
+
+	ret = pwmchip_add(&info->chip);
+	if (ret)
+		goto err;
+
+	platform_set_drvdata(pdev, info);
+	return 0;
+err:
+	clk_disable_unprepare(info->clk);
+	return ret;
+}
+
+static int hi3620_pwm_remove(struct platform_device *pdev)
+{
+	struct hi3620_pwm_info *info;
+
+	info = platform_get_drvdata(pdev);
+	pwmchip_remove(&info->chip);
+	clk_disable_unprepare(info->clk);
+	return 0;
+}
+
+static struct of_device_id hi3620_pwm_of_match[] = {
+	{ .compatible = "hisilicon,hi3620-pwm" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, hi3620_pwm_of_match);
+
+static struct platform_driver hi3620_pwm_driver = {
+	.driver = {
+		.name = "hi3620-pwm",
+		.of_match_table = of_match_ptr(hi3620_pwm_of_match),
+	},
+	.probe = hi3620_pwm_probe,
+	.remove = hi3620_pwm_remove,
+};
+module_platform_driver(hi3620_pwm_driver);
+
+MODULE_LICENSE("GPLv2");
+MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@linaro.org");
+MODULE_ALIAS("platform:hi3620-pwm");