diff options
Diffstat (limited to 'drivers/pwm/pwm-rockchip.c')
-rw-r--r-- | drivers/pwm/pwm-rockchip.c | 403 |
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..1f3079562 --- /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 void 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; + + 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->pclk); +} + +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; + + 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->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; + struct resource *r; + 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; + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + pc->base = devm_ioremap_resource(&pdev->dev, r); + 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 bus 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)) { + ret = PTR_ERR(pc->pclk); + if (ret != -EPROBE_DEFER) + dev_err(&pdev->dev, "Can't get APB clk: %d\n", ret); + return ret; + } + + ret = clk_prepare_enable(pc->clk); + if (ret) { + dev_err(&pdev->dev, "Can't prepare enable bus clk: %d\n", ret); + return ret; + } + + ret = clk_prepare_enable(pc->pclk); + if (ret) { + dev_err(&pdev->dev, "Can't prepare enable APB clk: %d\n", ret); + 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.base = -1; + pc->chip.npwm = 1; + + if (pc->data->supports_polarity) { + pc->chip.of_xlate = of_pwm_xlate_with_flags; + pc->chip.of_pwm_n_cells = 3; + } + + 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(&pdev->dev, "pwmchip_add() failed: %d\n", ret); + 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); + + clk_unprepare(pc->pclk); + clk_unprepare(pc->clk); + + return pwmchip_remove(&pc->chip); +} + +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"); |