| // 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); |
| if (pc->data->supports_polarity) |
| state->enabled = ((val & enable_conf) != enable_conf) ? |
| false : true; |
| else |
| state->enabled = ((val & enable_conf) == enable_conf) ? |
| true : false; |
| |
| 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; |
| 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)) { |
| ret = PTR_ERR(pc->clk); |
| if (ret != -EPROBE_DEFER) |
| dev_err(&pdev->dev, "Can't get bus clk: %d\n", |
| ret); |
| return ret; |
| } |
| } |
| |
| 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(pc->pclk); |
| if (ret) { |
| dev_err(&pdev->dev, "Can't prepare 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; |
| } |
| |
| 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 (!pwm_is_enabled(pc->chip.pwms)) |
| clk_disable(pc->clk); |
| |
| return 0; |
| |
| err_pclk: |
| clk_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"); |