summaryrefslogtreecommitdiffstats
path: root/drivers/pwm/pwm-rockchip.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/pwm/pwm-rockchip.c')
-rw-r--r--drivers/pwm/pwm-rockchip.c403
1 files changed, 403 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c
new file mode 100644
index 000000000..3ec7d1756
--- /dev/null
+++ b/drivers/pwm/pwm-rockchip.c
@@ -0,0 +1,403 @@
+// 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 <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/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 *c)
+{
+ return container_of(c, struct rockchip_pwm_chip, chip);
+}
+
+static int rockchip_pwm_get_state(struct pwm_chip *chip,
+ struct pwm_device *pwm,
+ struct pwm_state *state)
+{
+ struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+ u32 enable_conf = pc->data->enable_conf;
+ unsigned long clk_rate;
+ u64 tmp;
+ u32 val;
+ int ret;
+
+ ret = clk_enable(pc->pclk);
+ if (ret)
+ return 0;
+
+ ret = clk_enable(pc->clk);
+ if (ret)
+ return 0;
+
+ clk_rate = clk_get_rate(pc->clk);
+
+ tmp = readl_relaxed(pc->base + pc->data->regs.period);
+ tmp *= pc->data->prescaler * NSEC_PER_SEC;
+ state->period = DIV_ROUND_CLOSEST_ULL(tmp, clk_rate);
+
+ tmp = readl_relaxed(pc->base + pc->data->regs.duty);
+ tmp *= pc->data->prescaler * NSEC_PER_SEC;
+ state->duty_cycle = DIV_ROUND_CLOSEST_ULL(tmp, clk_rate);
+
+ val = readl_relaxed(pc->base + pc->data->regs.ctrl);
+ state->enabled = (val & enable_conf) == enable_conf;
+
+ if (pc->data->supports_polarity && !(val & PWM_DUTY_POSITIVE))
+ state->polarity = PWM_POLARITY_INVERSED;
+ else
+ state->polarity = PWM_POLARITY_NORMAL;
+
+ clk_disable(pc->clk);
+ clk_disable(pc->pclk);
+
+ return 0;
+}
+
+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 = {
+ .get_state = rockchip_pwm_get_state,
+ .apply = rockchip_pwm_apply,
+ .owner = THIS_MODULE,
+};
+
+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 platform_device *pdev)
+{
+ const struct of_device_id *id;
+ struct rockchip_pwm_chip *pc;
+ u32 enable_conf, ctrl;
+ bool enabled;
+ int ret, count;
+
+ id = of_match_device(rockchip_pwm_dt_ids, &pdev->dev);
+ if (!id)
+ return -EINVAL;
+
+ pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
+ if (!pc)
+ return -ENOMEM;
+
+ pc->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(pc->base))
+ return PTR_ERR(pc->base);
+
+ pc->clk = devm_clk_get(&pdev->dev, "pwm");
+ if (IS_ERR(pc->clk)) {
+ pc->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(pc->clk))
+ return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk),
+ "Can't get PWM clk\n");
+ }
+
+ count = of_count_phandle_with_args(pdev->dev.of_node,
+ "clocks", "#clock-cells");
+ if (count == 2)
+ pc->pclk = devm_clk_get(&pdev->dev, "pclk");
+ else
+ pc->pclk = pc->clk;
+
+ if (IS_ERR(pc->pclk))
+ return dev_err_probe(&pdev->dev, PTR_ERR(pc->pclk), "Can't get APB clk\n");
+
+ ret = clk_prepare_enable(pc->clk);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret, "Can't prepare enable PWM clk\n");
+
+ ret = clk_prepare_enable(pc->pclk);
+ if (ret) {
+ dev_err_probe(&pdev->dev, ret, "Can't prepare enable APB clk\n");
+ goto err_clk;
+ }
+
+ platform_set_drvdata(pdev, pc);
+
+ pc->data = id->data;
+ pc->chip.dev = &pdev->dev;
+ pc->chip.ops = &rockchip_pwm_ops;
+ pc->chip.npwm = 1;
+
+ enable_conf = pc->data->enable_conf;
+ ctrl = readl_relaxed(pc->base + pc->data->regs.ctrl);
+ enabled = (ctrl & enable_conf) == enable_conf;
+
+ ret = pwmchip_add(&pc->chip);
+ if (ret < 0) {
+ dev_err_probe(&pdev->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 int rockchip_pwm_remove(struct platform_device *pdev)
+{
+ struct rockchip_pwm_chip *pc = platform_get_drvdata(pdev);
+
+ pwmchip_remove(&pc->chip);
+
+ clk_unprepare(pc->pclk);
+ clk_unprepare(pc->clk);
+
+ return 0;
+}
+
+static struct platform_driver rockchip_pwm_driver = {
+ .driver = {
+ .name = "rockchip-pwm",
+ .of_match_table = rockchip_pwm_dt_ids,
+ },
+ .probe = rockchip_pwm_probe,
+ .remove = rockchip_pwm_remove,
+};
+module_platform_driver(rockchip_pwm_driver);
+
+MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
+MODULE_DESCRIPTION("Rockchip SoC PWM driver");
+MODULE_LICENSE("GPL v2");