1 files changed, 348 insertions, 0 deletions

diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c
new file mode 100644
index 0000000000..960867c520
--- /dev/null
+++ b/drivers/pwm/pwm-rockchip.c
@@ -0,0 +1,348 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * PWM driver for Rockchip SoCs
+ *
+ * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
+ * Copyright (C) 2014 ROCKCHIP, Inc.
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <module.h>
+#include <of.h>
+#include <linux/device.h>
+#include <pwm.h>
+#include <linux/time.h>
+
+#define PWM_CTRL_TIMER_EN	(1 << 0)
+#define PWM_CTRL_OUTPUT_EN	(1 << 3)
+
+#define PWM_ENABLE		(1 << 0)
+#define PWM_CONTINUOUS		(1 << 1)
+#define PWM_DUTY_POSITIVE	(1 << 3)
+#define PWM_DUTY_NEGATIVE	(0 << 3)
+#define PWM_INACTIVE_NEGATIVE	(0 << 4)
+#define PWM_INACTIVE_POSITIVE	(1 << 4)
+#define PWM_POLARITY_MASK	(PWM_DUTY_POSITIVE | PWM_INACTIVE_POSITIVE)
+#define PWM_OUTPUT_LEFT		(0 << 5)
+#define PWM_LOCK_EN		(1 << 6)
+#define PWM_LP_DISABLE		(0 << 8)
+
+struct rockchip_pwm_chip {
+	struct pwm_chip chip;
+	struct clk *clk;
+	struct clk *pclk;
+	const struct rockchip_pwm_data *data;
+	void __iomem *base;
+};
+
+struct rockchip_pwm_regs {
+	unsigned long duty;
+	unsigned long period;
+	unsigned long cntr;
+	unsigned long ctrl;
+};
+
+struct rockchip_pwm_data {
+	struct rockchip_pwm_regs regs;
+	unsigned int prescaler;
+	bool supports_polarity;
+	bool supports_lock;
+	u32 enable_conf;
+};
+
+static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *chip)
+{
+	return container_of(chip, struct rockchip_pwm_chip, chip);
+}
+
+static void rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+			       const struct pwm_state *state)
+{
+	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+	unsigned long period, duty;
+	u64 clk_rate, div;
+	u32 ctrl;
+
+	clk_rate = clk_get_rate(pc->clk);
+
+	/*
+	 * Since period and duty cycle registers have a width of 32
+	 * bits, every possible input period can be obtained using the
+	 * default prescaler value for all practical clock rate values.
+	 */
+	div = clk_rate * state->period;
+	period = DIV_ROUND_CLOSEST_ULL(div,
+				       pc->data->prescaler * NSEC_PER_SEC);
+
+	div = clk_rate * state->duty_cycle;
+	duty = DIV_ROUND_CLOSEST_ULL(div, pc->data->prescaler * NSEC_PER_SEC);
+
+	/*
+	 * Lock the period and duty of previous configuration, then
+	 * change the duty and period, that would not be effective.
+	 */
+	ctrl = readl_relaxed(pc->base + pc->data->regs.ctrl);
+	if (pc->data->supports_lock) {
+		ctrl |= PWM_LOCK_EN;
+		writel_relaxed(ctrl, pc->base + pc->data->regs.ctrl);
+	}
+
+	writel(period, pc->base + pc->data->regs.period);
+	writel(duty, pc->base + pc->data->regs.duty);
+
+	if (pc->data->supports_polarity) {
+		ctrl &= ~PWM_POLARITY_MASK;
+		if (state->polarity == PWM_POLARITY_INVERSED)
+			ctrl |= PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSITIVE;
+		else
+			ctrl |= PWM_DUTY_POSITIVE | PWM_INACTIVE_NEGATIVE;
+	}
+
+	/*
+	 * Unlock and set polarity at the same time,
+	 * the configuration of duty, period and polarity
+	 * would be effective together at next period.
+	 */
+	if (pc->data->supports_lock)
+		ctrl &= ~PWM_LOCK_EN;
+
+	writel(ctrl, pc->base + pc->data->regs.ctrl);
+}
+
+static int rockchip_pwm_enable(struct pwm_chip *chip,
+			       struct pwm_device *pwm,
+			       bool enable)
+{
+	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+	u32 enable_conf = pc->data->enable_conf;
+	int ret;
+	u32 val;
+
+	if (enable) {
+		ret = clk_enable(pc->clk);
+		if (ret)
+			return ret;
+	}
+
+	val = readl_relaxed(pc->base + pc->data->regs.ctrl);
+
+	if (enable)
+		val |= enable_conf;
+	else
+		val &= ~enable_conf;
+
+	writel_relaxed(val, pc->base + pc->data->regs.ctrl);
+
+	if (!enable)
+		clk_disable(pc->clk);
+
+	return 0;
+}
+
+static int rockchip_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			      const struct pwm_state *state)
+{
+	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+	struct pwm_state curstate;
+	bool enabled;
+	int ret = 0;
+
+	ret = clk_enable(pc->pclk);
+	if (ret)
+		return ret;
+
+	ret = clk_enable(pc->clk);
+	if (ret)
+		return ret;
+
+	pwm_get_state(pwm, &curstate);
+	enabled = curstate.enabled;
+
+	if (state->polarity != curstate.polarity && enabled &&
+	    !pc->data->supports_lock) {
+		ret = rockchip_pwm_enable(chip, pwm, false);
+		if (ret)
+			goto out;
+		enabled = false;
+	}
+
+	rockchip_pwm_config(chip, pwm, state);
+	if (state->enabled != enabled) {
+		ret = rockchip_pwm_enable(chip, pwm, state->enabled);
+		if (ret)
+			goto out;
+	}
+
+out:
+	clk_disable(pc->clk);
+	clk_disable(pc->pclk);
+
+	return ret;
+}
+
+static const struct pwm_ops rockchip_pwm_ops = {
+	.apply = rockchip_pwm_apply,
+};
+
+static const struct rockchip_pwm_data pwm_data_v1 = {
+	.regs = {
+		.duty = 0x04,
+		.period = 0x08,
+		.cntr = 0x00,
+		.ctrl = 0x0c,
+	},
+	.prescaler = 2,
+	.supports_polarity = false,
+	.supports_lock = false,
+	.enable_conf = PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN,
+};
+
+static const struct rockchip_pwm_data pwm_data_v2 = {
+	.regs = {
+		.duty = 0x08,
+		.period = 0x04,
+		.cntr = 0x00,
+		.ctrl = 0x0c,
+	},
+	.prescaler = 1,
+	.supports_polarity = true,
+	.supports_lock = false,
+	.enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
+		       PWM_CONTINUOUS,
+};
+
+static const struct rockchip_pwm_data pwm_data_vop = {
+	.regs = {
+		.duty = 0x08,
+		.period = 0x04,
+		.cntr = 0x0c,
+		.ctrl = 0x00,
+	},
+	.prescaler = 1,
+	.supports_polarity = true,
+	.supports_lock = false,
+	.enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
+		       PWM_CONTINUOUS,
+};
+
+static const struct rockchip_pwm_data pwm_data_v3 = {
+	.regs = {
+		.duty = 0x08,
+		.period = 0x04,
+		.cntr = 0x00,
+		.ctrl = 0x0c,
+	},
+	.prescaler = 1,
+	.supports_polarity = true,
+	.supports_lock = true,
+	.enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
+		       PWM_CONTINUOUS,
+};
+
+static const struct of_device_id rockchip_pwm_dt_ids[] = {
+	{ .compatible = "rockchip,rk2928-pwm", .data = &pwm_data_v1},
+	{ .compatible = "rockchip,rk3288-pwm", .data = &pwm_data_v2},
+	{ .compatible = "rockchip,vop-pwm", .data = &pwm_data_vop},
+	{ .compatible = "rockchip,rk3328-pwm", .data = &pwm_data_v3},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rockchip_pwm_dt_ids);
+
+static int rockchip_pwm_probe(struct device *dev)
+{
+	struct rockchip_pwm_chip *pc;
+	u32 enable_conf, ctrl;
+	bool enabled;
+	int ret, count;
+
+	pc = devm_kzalloc(dev, sizeof(*pc), GFP_KERNEL);
+	if (!pc)
+		return -ENOMEM;
+
+	pc->base = dev_platform_ioremap_resource(dev, 0);
+	if (IS_ERR(pc->base))
+		return PTR_ERR(pc->base);
+
+	pc->clk = clk_get(dev, "pwm");
+	if (IS_ERR(pc->clk)) {
+		pc->clk = clk_get(dev, NULL);
+		if (IS_ERR(pc->clk))
+			return dev_err_probe(dev, PTR_ERR(pc->clk),
+					     "Can't get PWM clk\n");
+	}
+
+	count = of_count_phandle_with_args(dev->of_node,
+					   "clocks", "#clock-cells");
+	if (count == 2)
+		pc->pclk = clk_get(dev, "pclk");
+	else
+		pc->pclk = pc->clk;
+
+	if (IS_ERR(pc->pclk))
+		return dev_err_probe(dev, PTR_ERR(pc->pclk), "Can't get APB clk\n");
+
+	ret = clk_prepare_enable(pc->clk);
+	if (ret)
+		return dev_err_probe(dev, ret, "Can't prepare enable PWM clk\n");
+
+	ret = clk_prepare_enable(pc->pclk);
+	if (ret) {
+		dev_err_probe(dev, ret, "Can't prepare enable APB clk\n");
+		goto err_clk;
+	}
+
+	dev->priv = pc;
+
+	pc->data = device_get_match_data(dev);
+	pc->chip.dev = dev;
+	pc->chip.ops = &rockchip_pwm_ops;
+
+	enable_conf = pc->data->enable_conf;
+	ctrl = readl_relaxed(pc->base + pc->data->regs.ctrl);
+	enabled = (ctrl & enable_conf) == enable_conf;
+
+	pc->chip.devname = of_alias_get(dev->of_node);
+	if (!pc->chip.devname)
+		pc->chip.devname = basprintf("pwm_%p", pc->base);
+
+	ret = pwmchip_add(&pc->chip);
+	if (ret < 0) {
+		dev_err_probe(dev, ret, "pwmchip_add() failed\n");
+		goto err_pclk;
+	}
+
+	/* Keep the PWM clk enabled if the PWM appears to be up and running. */
+	if (!enabled)
+		clk_disable(pc->clk);
+
+	clk_disable(pc->pclk);
+
+	return 0;
+
+err_pclk:
+	clk_disable_unprepare(pc->pclk);
+err_clk:
+	clk_disable_unprepare(pc->clk);
+
+	return ret;
+}
+
+static void rockchip_pwm_remove(struct device *dev)
+{
+	struct rockchip_pwm_chip *pc = dev->priv;
+
+	pwmchip_remove(&pc->chip);
+}
+
+static struct driver rockchip_pwm_driver = {
+	.name = "rockchip-pwm",
+	.of_match_table = rockchip_pwm_dt_ids,
+	.probe = rockchip_pwm_probe,
+	.remove = rockchip_pwm_remove,
+};
+device_platform_driver(rockchip_pwm_driver);
+
+MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
+MODULE_DESCRIPTION("Rockchip SoC PWM driver");
+MODULE_LICENSE("GPL v2");