v4.19.13 snapshot.
diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c
new file mode 100644
index 0000000..eb6674c
--- /dev/null
+++ b/drivers/pwm/pwm-mediatek.c
@@ -0,0 +1,325 @@
+/*
+ * Mediatek Pulse Width Modulator driver
+ *
+ * Copyright (C) 2015 John Crispin <blogic@openwrt.org>
+ * Copyright (C) 2017 Zhi Mao <zhi.mao@mediatek.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+/* PWM registers and bits definitions */
+#define PWMCON			0x00
+#define PWMHDUR			0x04
+#define PWMLDUR			0x08
+#define PWMGDUR			0x0c
+#define PWMWAVENUM		0x28
+#define PWMDWIDTH		0x2c
+#define PWM45DWIDTH_FIXUP	0x30
+#define PWMTHRES		0x30
+#define PWM45THRES_FIXUP	0x34
+
+#define PWM_CLK_DIV_MAX		7
+
+enum {
+	MTK_CLK_MAIN = 0,
+	MTK_CLK_TOP,
+	MTK_CLK_PWM1,
+	MTK_CLK_PWM2,
+	MTK_CLK_PWM3,
+	MTK_CLK_PWM4,
+	MTK_CLK_PWM5,
+	MTK_CLK_PWM6,
+	MTK_CLK_PWM7,
+	MTK_CLK_PWM8,
+	MTK_CLK_MAX,
+};
+
+static const char * const mtk_pwm_clk_name[MTK_CLK_MAX] = {
+	"main", "top", "pwm1", "pwm2", "pwm3", "pwm4", "pwm5", "pwm6", "pwm7",
+	"pwm8"
+};
+
+struct mtk_pwm_platform_data {
+	unsigned int num_pwms;
+	bool pwm45_fixup;
+	bool has_clks;
+};
+
+/**
+ * struct mtk_pwm_chip - struct representing PWM chip
+ * @chip: linux PWM chip representation
+ * @regs: base address of PWM chip
+ * @clks: list of clocks
+ */
+struct mtk_pwm_chip {
+	struct pwm_chip chip;
+	void __iomem *regs;
+	struct clk *clks[MTK_CLK_MAX];
+	const struct mtk_pwm_platform_data *soc;
+};
+
+static const unsigned int mtk_pwm_reg_offset[] = {
+	0x0010, 0x0050, 0x0090, 0x00d0, 0x0110, 0x0150, 0x0190, 0x0220
+};
+
+static inline struct mtk_pwm_chip *to_mtk_pwm_chip(struct pwm_chip *chip)
+{
+	return container_of(chip, struct mtk_pwm_chip, chip);
+}
+
+static int mtk_pwm_clk_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip);
+	int ret;
+
+	if (!pc->soc->has_clks)
+		return 0;
+
+	ret = clk_prepare_enable(pc->clks[MTK_CLK_TOP]);
+	if (ret < 0)
+		return ret;
+
+	ret = clk_prepare_enable(pc->clks[MTK_CLK_MAIN]);
+	if (ret < 0)
+		goto disable_clk_top;
+
+	ret = clk_prepare_enable(pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]);
+	if (ret < 0)
+		goto disable_clk_main;
+
+	return 0;
+
+disable_clk_main:
+	clk_disable_unprepare(pc->clks[MTK_CLK_MAIN]);
+disable_clk_top:
+	clk_disable_unprepare(pc->clks[MTK_CLK_TOP]);
+
+	return ret;
+}
+
+static void mtk_pwm_clk_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip);
+
+	if (!pc->soc->has_clks)
+		return;
+
+	clk_disable_unprepare(pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]);
+	clk_disable_unprepare(pc->clks[MTK_CLK_MAIN]);
+	clk_disable_unprepare(pc->clks[MTK_CLK_TOP]);
+}
+
+static inline u32 mtk_pwm_readl(struct mtk_pwm_chip *chip, unsigned int num,
+				unsigned int offset)
+{
+	return readl(chip->regs + mtk_pwm_reg_offset[num] + offset);
+}
+
+static inline void mtk_pwm_writel(struct mtk_pwm_chip *chip,
+				  unsigned int num, unsigned int offset,
+				  u32 value)
+{
+	writel(value, chip->regs + mtk_pwm_reg_offset[num] + offset);
+}
+
+static int mtk_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+			  int duty_ns, int period_ns)
+{
+	struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip);
+	struct clk *clk = pc->clks[MTK_CLK_PWM1 + pwm->hwpwm];
+	u32 clkdiv = 0, cnt_period, cnt_duty, reg_width = PWMDWIDTH,
+	    reg_thres = PWMTHRES;
+	u64 resolution;
+	int ret;
+
+	ret = mtk_pwm_clk_enable(chip, pwm);
+	if (ret < 0)
+		return ret;
+
+	/* Using resolution in picosecond gets accuracy higher */
+	resolution = (u64)NSEC_PER_SEC * 1000;
+	do_div(resolution, clk_get_rate(clk));
+
+	cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000, resolution);
+	while (cnt_period > 8191) {
+		resolution *= 2;
+		clkdiv++;
+		cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000,
+						   resolution);
+	}
+
+	if (clkdiv > PWM_CLK_DIV_MAX) {
+		mtk_pwm_clk_disable(chip, pwm);
+		dev_err(chip->dev, "period %d not supported\n", period_ns);
+		return -EINVAL;
+	}
+
+	if (pc->soc->pwm45_fixup && pwm->hwpwm > 2) {
+		/*
+		 * PWM[4,5] has distinct offset for PWMDWIDTH and PWMTHRES
+		 * from the other PWMs on MT7623.
+		 */
+		reg_width = PWM45DWIDTH_FIXUP;
+		reg_thres = PWM45THRES_FIXUP;
+	}
+
+	cnt_duty = DIV_ROUND_CLOSEST_ULL((u64)duty_ns * 1000, resolution);
+	mtk_pwm_writel(pc, pwm->hwpwm, PWMCON, BIT(15) | clkdiv);
+	mtk_pwm_writel(pc, pwm->hwpwm, reg_width, cnt_period);
+	mtk_pwm_writel(pc, pwm->hwpwm, reg_thres, cnt_duty);
+
+	mtk_pwm_clk_disable(chip, pwm);
+
+	return 0;
+}
+
+static int mtk_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip);
+	u32 value;
+	int ret;
+
+	ret = mtk_pwm_clk_enable(chip, pwm);
+	if (ret < 0)
+		return ret;
+
+	value = readl(pc->regs);
+	value |= BIT(pwm->hwpwm);
+	writel(value, pc->regs);
+
+	return 0;
+}
+
+static void mtk_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip);
+	u32 value;
+
+	value = readl(pc->regs);
+	value &= ~BIT(pwm->hwpwm);
+	writel(value, pc->regs);
+
+	mtk_pwm_clk_disable(chip, pwm);
+}
+
+static const struct pwm_ops mtk_pwm_ops = {
+	.config = mtk_pwm_config,
+	.enable = mtk_pwm_enable,
+	.disable = mtk_pwm_disable,
+	.owner = THIS_MODULE,
+};
+
+static int mtk_pwm_probe(struct platform_device *pdev)
+{
+	const struct mtk_pwm_platform_data *data;
+	struct mtk_pwm_chip *pc;
+	struct resource *res;
+	unsigned int i;
+	int ret;
+
+	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
+	if (!pc)
+		return -ENOMEM;
+
+	data = of_device_get_match_data(&pdev->dev);
+	if (data == NULL)
+		return -EINVAL;
+	pc->soc = data;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	pc->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(pc->regs))
+		return PTR_ERR(pc->regs);
+
+	for (i = 0; i < data->num_pwms + 2 && pc->soc->has_clks; i++) {
+		pc->clks[i] = devm_clk_get(&pdev->dev, mtk_pwm_clk_name[i]);
+		if (IS_ERR(pc->clks[i])) {
+			dev_err(&pdev->dev, "clock: %s fail: %ld\n",
+				mtk_pwm_clk_name[i], PTR_ERR(pc->clks[i]));
+			return PTR_ERR(pc->clks[i]);
+		}
+	}
+
+	platform_set_drvdata(pdev, pc);
+
+	pc->chip.dev = &pdev->dev;
+	pc->chip.ops = &mtk_pwm_ops;
+	pc->chip.base = -1;
+	pc->chip.npwm = data->num_pwms;
+
+	ret = pwmchip_add(&pc->chip);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int mtk_pwm_remove(struct platform_device *pdev)
+{
+	struct mtk_pwm_chip *pc = platform_get_drvdata(pdev);
+
+	return pwmchip_remove(&pc->chip);
+}
+
+static const struct mtk_pwm_platform_data mt2712_pwm_data = {
+	.num_pwms = 8,
+	.pwm45_fixup = false,
+	.has_clks = true,
+};
+
+static const struct mtk_pwm_platform_data mt7622_pwm_data = {
+	.num_pwms = 6,
+	.pwm45_fixup = false,
+	.has_clks = true,
+};
+
+static const struct mtk_pwm_platform_data mt7623_pwm_data = {
+	.num_pwms = 5,
+	.pwm45_fixup = true,
+	.has_clks = true,
+};
+
+static const struct mtk_pwm_platform_data mt7628_pwm_data = {
+	.num_pwms = 4,
+	.pwm45_fixup = true,
+	.has_clks = false,
+};
+
+static const struct of_device_id mtk_pwm_of_match[] = {
+	{ .compatible = "mediatek,mt2712-pwm", .data = &mt2712_pwm_data },
+	{ .compatible = "mediatek,mt7622-pwm", .data = &mt7622_pwm_data },
+	{ .compatible = "mediatek,mt7623-pwm", .data = &mt7623_pwm_data },
+	{ .compatible = "mediatek,mt7628-pwm", .data = &mt7628_pwm_data },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, mtk_pwm_of_match);
+
+static struct platform_driver mtk_pwm_driver = {
+	.driver = {
+		.name = "mtk-pwm",
+		.of_match_table = mtk_pwm_of_match,
+	},
+	.probe = mtk_pwm_probe,
+	.remove = mtk_pwm_remove,
+};
+module_platform_driver(mtk_pwm_driver);
+
+MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
+MODULE_LICENSE("GPL");