From 4919e67557eaebb9f155950e7cac547a507b59e5 Mon Sep 17 00:00:00 2001 From: Ban Tao Date: Tue, 2 Mar 2021 20:37:37 +0800 Subject: [PATCH 060/117] pwm: sunxi: Add Allwinner SoC PWM controller driver The Allwinner R818, A133, R329, V536 and V833 has a new PWM controller IP compared to the older Allwinner SoCs. Signed-off-by: Ban Tao --- MAINTAINERS | 6 + drivers/pwm/Kconfig | 11 + drivers/pwm/Makefile | 1 + drivers/pwm/pwm-sun8i-v536.c | 401 +++++++++++++++++++++++++++++++++++ 4 files changed, 419 insertions(+) create mode 100644 drivers/pwm/pwm-sun8i-v536.c --- a/MAINTAINERS +++ b/MAINTAINERS @@ -802,6 +802,12 @@ S: Maintained F: Documentation/devicetree/bindings/hwlock/allwinner,sun6i-a31-hwspinlock.yaml F: drivers/hwspinlock/sun6i_hwspinlock.c +ALLWINNER PWM DRIVER +M: Ban Tao +L: linux-pwm@vger.kernel.org +S: Maintained +F: drivers/pwm/pwm-sun8i-v536.c + ALLWINNER THERMAL DRIVER M: Vasily Khoruzhick M: Yangtao Li --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -582,6 +582,17 @@ config PWM_SUN4I To compile this driver as a module, choose M here: the module will be called pwm-sun4i. +config PWM_SUN8I_V536 + tristate "Allwinner SUN8I_V536 PWM support" + depends on ARCH_SUNXI || COMPILE_TEST + depends on HAS_IOMEM && COMMON_CLK + help + Enhanced PWM framework driver for Allwinner R818, A133, R329, + V536 and V833 SoCs. + + To compile this driver as a module, choose M here: the module + will be called pwm-sun8i-v536. + config PWM_SUNPLUS tristate "Sunplus PWM support" depends on ARCH_SUNPLUS || COMPILE_TEST --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -54,6 +54,7 @@ obj-$(CONFIG_PWM_STM32) += pwm-stm32.o obj-$(CONFIG_PWM_STM32_LP) += pwm-stm32-lp.o obj-$(CONFIG_PWM_STMPE) += pwm-stmpe.o obj-$(CONFIG_PWM_SUN4I) += pwm-sun4i.o +obj-$(CONFIG_PWM_SUN8I_V536) += pwm-sun8i-v536.o obj-$(CONFIG_PWM_SUNPLUS) += pwm-sunplus.o obj-$(CONFIG_PWM_TEGRA) += pwm-tegra.o obj-$(CONFIG_PWM_TIECAP) += pwm-tiecap.o --- /dev/null +++ b/drivers/pwm/pwm-sun8i-v536.c @@ -0,0 +1,401 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Driver for Allwinner sun8i-v536 Pulse Width Modulation Controller + * + * Copyright (C) 2021 Ban Tao + * + * + * Limitations: + * - When PWM is disabled, the output is driven to inactive. + * - If the register is reconfigured while PWM is running, + * it does not complete the currently running period. + * - If the user input duty is beyond acceptible limits, + * -EINVAL is returned. + */ + +#include +#include +#include +#include +#include +#include +#include + +#define PWM_GET_CLK_OFFSET(chan) (0x20 + ((chan >> 1) * 0x4)) +#define PWM_CLK_APB_SCR BIT(7) +#define PWM_DIV_M 0 +#define PWM_DIV_M_MASK GENMASK(3, PWM_DIV_M) + +#define PWM_CLK_REG 0x40 +#define PWM_CLK_GATING BIT(0) + +#define PWM_ENABLE_REG 0x80 +#define PWM_EN BIT(0) + +#define PWM_CTL_REG(chan) (0x100 + 0x20 * chan) +#define PWM_ACT_STA BIT(8) +#define PWM_PRESCAL_K 0 +#define PWM_PRESCAL_K_MASK GENMASK(7, PWM_PRESCAL_K) + +#define PWM_PERIOD_REG(chan) (0x104 + 0x20 * chan) +#define PWM_ENTIRE_CYCLE 16 +#define PWM_ENTIRE_CYCLE_MASK GENMASK(31, PWM_ENTIRE_CYCLE) +#define PWM_ACT_CYCLE 0 +#define PWM_ACT_CYCLE_MASK GENMASK(15, PWM_ACT_CYCLE) + +#define BIT_CH(bit, chan) ((bit) << (chan)) +#define SET_BITS(shift, mask, reg, val) \ + (((reg) & ~mask) | (val << (shift))) + +#define PWM_OSC_CLK 24000000 +#define PWM_PRESCALER_MAX 256 +#define PWM_CLK_DIV_M__MAX 9 +#define PWM_ENTIRE_CYCLE_MAX 65536 + +struct sun8i_pwm_data { + unsigned int npwm; +}; + +struct sun8i_pwm_chip { + struct pwm_chip chip; + struct clk *clk; + struct reset_control *rst_clk; + void __iomem *base; + const struct sun8i_pwm_data *data; +}; + +static inline struct sun8i_pwm_chip *to_sun8i_pwm_chip(struct pwm_chip *chip) +{ + return container_of(chip, struct sun8i_pwm_chip, chip); +} + +static inline u32 sun8i_pwm_readl(struct sun8i_pwm_chip *chip, + unsigned long offset) +{ + return readl(chip->base + offset); +} + +static inline void sun8i_pwm_writel(struct sun8i_pwm_chip *chip, + u32 val, unsigned long offset) +{ + writel(val, chip->base + offset); +} + +static void sun8i_pwm_get_state(struct pwm_chip *chip, + struct pwm_device *pwm, + struct pwm_state *state) +{ + struct sun8i_pwm_chip *pc = to_sun8i_pwm_chip(chip); + u64 clk_rate; + u32 tmp, entire_cycles, active_cycles; + unsigned int prescaler, div_m; + + tmp = sun8i_pwm_readl(pc, PWM_GET_CLK_OFFSET(pwm->hwpwm)); + if (tmp & PWM_CLK_APB_SCR) + clk_rate = clk_get_rate(pc->clk); + else + clk_rate = PWM_OSC_CLK; + + tmp = sun8i_pwm_readl(pc, PWM_GET_CLK_OFFSET(pwm->hwpwm)); + div_m = 0x1 << (tmp & PWM_DIV_M_MASK); + + tmp = sun8i_pwm_readl(pc, PWM_CTL_REG(pwm->hwpwm)); + prescaler = (tmp & PWM_PRESCAL_K_MASK) + 1; + + tmp = sun8i_pwm_readl(pc, PWM_PERIOD_REG(pwm->hwpwm)); + entire_cycles = (tmp >> PWM_ENTIRE_CYCLE) + 1; + active_cycles = (tmp & PWM_ACT_CYCLE_MASK); + + /* (clk / div_m / prescaler) / entire_cycles = NSEC_PER_SEC / period_ns. */ + state->period = DIV_ROUND_CLOSEST_ULL(entire_cycles * NSEC_PER_SEC, + clk_rate) * div_m * prescaler; + /* duty_ns / period_ns = active_cycles / entire_cycles. */ + state->duty_cycle = DIV_ROUND_CLOSEST_ULL(active_cycles * state->period, + entire_cycles); + + /* parsing polarity */ + tmp = sun8i_pwm_readl(pc, PWM_CTL_REG(pwm->hwpwm)); + if (tmp & PWM_ACT_STA) + state->polarity = PWM_POLARITY_NORMAL; + else + state->polarity = PWM_POLARITY_INVERSED; + + /* parsing enabled */ + tmp = sun8i_pwm_readl(pc, PWM_ENABLE_REG); + if (tmp & BIT_CH(PWM_EN, pwm->hwpwm)) + state->enabled = true; + else + state->enabled = false; + + dev_dbg(chip->dev, "duty_ns=%lld period_ns=%lld polarity=%s enabled=%s.\n", + state->duty_cycle, state->period, + state->polarity ? "inversed":"normal", + state->enabled ? "true":"false"); +} + +static void sun8i_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm, + enum pwm_polarity polarity) +{ + struct sun8i_pwm_chip *pc = to_sun8i_pwm_chip(chip); + u32 temp; + + temp = sun8i_pwm_readl(pc, PWM_CTL_REG(pwm->hwpwm)); + + if (polarity == PWM_POLARITY_NORMAL) + temp |= PWM_ACT_STA; + else + temp &= ~PWM_ACT_STA; + + sun8i_pwm_writel(pc, temp, PWM_CTL_REG(pwm->hwpwm)); +} + +static int sun8i_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_state *state) +{ + struct sun8i_pwm_chip *pc = to_sun8i_pwm_chip(chip); + unsigned long long c; + unsigned long entire_cycles, active_cycles; + unsigned int div_m, prescaler; + u64 duty_ns = state->duty_cycle, period_ns = state->period; + u32 config; + int ret = 0; + + if (period_ns > 334) { + /* if freq < 3M, then select 24M clock */ + c = PWM_OSC_CLK; + config = sun8i_pwm_readl(pc, PWM_GET_CLK_OFFSET(pwm->hwpwm)); + config &= ~PWM_CLK_APB_SCR; + sun8i_pwm_writel(pc, config, PWM_GET_CLK_OFFSET(pwm->hwpwm)); + } else { + /* if freq > 3M, then select APB as clock */ + c = clk_get_rate(pc->clk); + config = sun8i_pwm_readl(pc, PWM_GET_CLK_OFFSET(pwm->hwpwm)); + config |= PWM_CLK_APB_SCR; + sun8i_pwm_writel(pc, config, PWM_GET_CLK_OFFSET(pwm->hwpwm)); + } + + dev_dbg(chip->dev, "duty_ns=%lld period_ns=%lld c =%llu.\n", + duty_ns, period_ns, c); + + /* + * (clk / div_m / prescaler) / entire_cycles = NSEC_PER_SEC / period_ns. + * So, entire_cycles = clk * period_ns / NSEC_PER_SEC / div_m / prescaler. + */ + c = c * period_ns; + c = DIV_ROUND_CLOSEST_ULL(c, NSEC_PER_SEC); + for (div_m = 0; div_m < PWM_CLK_DIV_M__MAX; div_m++) { + for (prescaler = 0; prescaler < PWM_PRESCALER_MAX; prescaler++) { + /* + * actual prescaler = prescaler(reg value) + 1. + * actual div_m = 0x1 << div_m(reg value). + */ + entire_cycles = ((unsigned long)c >> div_m)/(prescaler + 1); + if (entire_cycles <= PWM_ENTIRE_CYCLE_MAX) + goto calc_end; + } + } + ret = -EINVAL; + goto exit; + +calc_end: + /* + * duty_ns / period_ns = active_cycles / entire_cycles. + * So, active_cycles = entire_cycles * duty_ns / period_ns. + */ + c = (unsigned long long)entire_cycles * duty_ns; + c = DIV_ROUND_CLOSEST_ULL(c, period_ns); + active_cycles = c; + if (entire_cycles == 0) + entire_cycles++; + + /* config clk div_m*/ + config = sun8i_pwm_readl(pc, PWM_GET_CLK_OFFSET(pwm->hwpwm)); + config = SET_BITS(PWM_DIV_M, PWM_DIV_M_MASK, config, div_m); + sun8i_pwm_writel(pc, config, PWM_GET_CLK_OFFSET(pwm->hwpwm)); + + /* config prescaler */ + config = sun8i_pwm_readl(pc, PWM_CTL_REG(pwm->hwpwm)); + config = SET_BITS(PWM_PRESCAL_K, PWM_PRESCAL_K_MASK, config, prescaler); + sun8i_pwm_writel(pc, config, PWM_CTL_REG(pwm->hwpwm)); + + /* config active and period cycles */ + config = sun8i_pwm_readl(pc, PWM_PERIOD_REG(pwm->hwpwm)); + config = SET_BITS(PWM_ACT_CYCLE, PWM_ACT_CYCLE_MASK, config, active_cycles); + config = SET_BITS(PWM_ENTIRE_CYCLE, PWM_ENTIRE_CYCLE_MASK, + config, (entire_cycles - 1)); + sun8i_pwm_writel(pc, config, PWM_PERIOD_REG(pwm->hwpwm)); + + dev_dbg(chip->dev, "active_cycles=%lu entire_cycles=%lu prescaler=%u div_m=%u\n", + active_cycles, entire_cycles, prescaler, div_m); + +exit: + return ret; +} + +static void sun8i_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm, + bool enable) +{ + struct sun8i_pwm_chip *pc = to_sun8i_pwm_chip(chip); + u32 clk, pwm_en; + + clk = sun8i_pwm_readl(pc, PWM_CLK_REG); + pwm_en = sun8i_pwm_readl(pc, PWM_ENABLE_REG); + + if (enable) { + clk |= BIT_CH(PWM_CLK_GATING, pwm->hwpwm); + sun8i_pwm_writel(pc, clk, PWM_CLK_REG); + + pwm_en |= BIT_CH(PWM_EN, pwm->hwpwm); + sun8i_pwm_writel(pc, pwm_en, PWM_ENABLE_REG); + } else { + pwm_en &= ~BIT_CH(PWM_EN, pwm->hwpwm); + sun8i_pwm_writel(pc, pwm_en, PWM_ENABLE_REG); + + clk &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm); + sun8i_pwm_writel(pc, clk, PWM_CLK_REG); + } +} + +static int sun8i_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_state *state) +{ + struct pwm_state curstate; + int ret; + + pwm_get_state(pwm, &curstate); + + ret = sun8i_pwm_config(chip, pwm, state); + + if (state->polarity != curstate.polarity) + sun8i_pwm_set_polarity(chip, pwm, state->polarity); + + if (state->enabled != curstate.enabled) + sun8i_pwm_enable(chip, pwm, state->enabled); + + return ret; +} + +static const struct pwm_ops sun8i_pwm_ops = { + .get_state = sun8i_pwm_get_state, + .apply = sun8i_pwm_apply, + .owner = THIS_MODULE, +}; + +static const struct sun8i_pwm_data sun8i_pwm_data_c9 = { + .npwm = 9, +}; + +static const struct sun8i_pwm_data sun50i_pwm_data_c16 = { + .npwm = 16, +}; + +static const struct of_device_id sun8i_pwm_dt_ids[] = { + { + .compatible = "allwinner,sun8i-v536-pwm", + .data = &sun8i_pwm_data_c9, + }, { + .compatible = "allwinner,sun50i-r818-pwm", + .data = &sun50i_pwm_data_c16, + }, { + /* sentinel */ + }, +}; +MODULE_DEVICE_TABLE(of, sun8i_pwm_dt_ids); + +static int sun8i_pwm_probe(struct platform_device *pdev) +{ + struct sun8i_pwm_chip *pc; + int ret; + + pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); + if (!pc) + return dev_err_probe(&pdev->dev, -ENOMEM, + "memory allocation failed\n"); + + pc->data = of_device_get_match_data(&pdev->dev); + if (!pc->data) + return dev_err_probe(&pdev->dev, -ENODEV, + "can't get match data\n"); + + pc->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(pc->base)) + return dev_err_probe(&pdev->dev, PTR_ERR(pc->base), + "can't remap pwm resource\n"); + + pc->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(pc->clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk), + "get clock failed\n"); + + pc->rst_clk = devm_reset_control_get_exclusive(&pdev->dev, NULL); + if (IS_ERR(pc->rst_clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(pc->rst_clk), + "get reset failed\n"); + + /* Deassert reset */ + ret = reset_control_deassert(pc->rst_clk); + if (ret < 0) + return dev_err_probe(&pdev->dev, ret, + "cannot deassert reset control\n"); + + ret = clk_prepare_enable(pc->clk); + if (ret) { + dev_err(&pdev->dev, "cannot prepare and enable clk %pe\n", + ERR_PTR(ret)); + goto err_clk; + } + + pc->chip.dev = &pdev->dev; + pc->chip.ops = &sun8i_pwm_ops; + pc->chip.npwm = pc->data->npwm; + pc->chip.of_xlate = of_pwm_xlate_with_flags; + pc->chip.base = -1; + pc->chip.of_pwm_n_cells = 3; + + ret = pwmchip_add(&pc->chip); + if (ret < 0) { + dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret); + goto err_pwm_add; + } + + platform_set_drvdata(pdev, pc); + + return 0; + +err_pwm_add: + clk_disable_unprepare(pc->clk); +err_clk: + reset_control_assert(pc->rst_clk); + + return ret; +} + +static int sun8i_pwm_remove(struct platform_device *pdev) +{ + struct sun8i_pwm_chip *pc = platform_get_drvdata(pdev); + int ret; + + ret = pwmchip_remove(&pc->chip); + if (ret) + return ret; + + clk_disable_unprepare(pc->clk); + reset_control_assert(pc->rst_clk); + + return 0; +} + +static struct platform_driver sun8i_pwm_driver = { + .driver = { + .name = "sun8i-pwm-v536", + .of_match_table = sun8i_pwm_dt_ids, + }, + .probe = sun8i_pwm_probe, + .remove = sun8i_pwm_remove, +}; +module_platform_driver(sun8i_pwm_driver); + +MODULE_ALIAS("platform:sun8i-v536-pwm"); +MODULE_AUTHOR("Ban Tao "); +MODULE_DESCRIPTION("Allwinner sun8i-v536 PWM driver"); +MODULE_LICENSE("GPL v2");