// SPDX-License-Identifier: GPL-2.0 /* * MediaTek Pulse Width Modulator driver * * Copyright (C) 2015 John Crispin <blogic@openwrt.org> * Copyright (C) 2017 Zhi Mao <zhi.mao@mediatek.com> * */ #include <linux/err.h> #include <linux/io.h> #include <linux/ioport.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/clk.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/pwm.h> #include <linux/slab.h> #include <linux/types.h> /* PWM registers and bits definitions */ #define PWMCON 0x00 #define PWMHDUR 0x04 #define PWMLDUR 0x08 #define PWMGDUR 0x0c #define PWMWAVENUM 0x28 #define PWMDWIDTH 0x2c #define PWM45DWIDTH_FIXUP 0x30 #define PWMTHRES 0x30 #define PWM45THRES_FIXUP 0x34 #define PWM_CLK_DIV_MAX 7 struct pwm_mediatek_of_data { unsigned int num_pwms; bool pwm45_fixup; }; /** * struct pwm_mediatek_chip - struct representing PWM chip * @chip: linux PWM chip representation * @regs: base address of PWM chip * @clk_top: the top clock generator * @clk_main: the clock used by PWM core * @clk_pwms: the clock used by each PWM channel * @clk_freq: the fix clock frequency of legacy MIPS SoC */ struct pwm_mediatek_chip { struct pwm_chip chip; void __iomem *regs; struct clk *clk_top; struct clk *clk_main; struct clk **clk_pwms; const struct pwm_mediatek_of_data *soc; }; static const unsigned int pwm_mediatek_reg_offset[] = { 0x0010, 0x0050, 0x0090, 0x00d0, 0x0110, 0x0150, 0x0190, 0x0220 }; static inline struct pwm_mediatek_chip * to_pwm_mediatek_chip(struct pwm_chip *chip) { return container_of(chip, struct pwm_mediatek_chip, chip); } static int pwm_mediatek_clk_enable(struct pwm_chip *chip, struct pwm_device *pwm) { struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip); int ret; ret = clk_prepare_enable(pc->clk_top); if (ret < 0) return ret; ret = clk_prepare_enable(pc->clk_main); if (ret < 0) goto disable_clk_top; ret = clk_prepare_enable(pc->clk_pwms[pwm->hwpwm]); if (ret < 0) goto disable_clk_main; return 0; disable_clk_main: clk_disable_unprepare(pc->clk_main); disable_clk_top: clk_disable_unprepare(pc->clk_top); return ret; } static void pwm_mediatek_clk_disable(struct pwm_chip *chip, struct pwm_device *pwm) { struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip); clk_disable_unprepare(pc->clk_pwms[pwm->hwpwm]); clk_disable_unprepare(pc->clk_main); clk_disable_unprepare(pc->clk_top); } static inline u32 pwm_mediatek_readl(struct pwm_mediatek_chip *chip, unsigned int num, unsigned int offset) { return readl(chip->regs + pwm_mediatek_reg_offset[num] + offset); } static inline void pwm_mediatek_writel(struct pwm_mediatek_chip *chip, unsigned int num, unsigned int offset, u32 value) { writel(value, chip->regs + pwm_mediatek_reg_offset[num] + offset); } static int pwm_mediatek_config(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns) { struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip); u32 clkdiv = 0, cnt_period, cnt_duty, reg_width = PWMDWIDTH, reg_thres = PWMTHRES; u64 resolution; int ret; ret = pwm_mediatek_clk_enable(chip, pwm); if (ret < 0) return ret; /* Using resolution in picosecond gets accuracy higher */ resolution = (u64)NSEC_PER_SEC * 1000; do_div(resolution, clk_get_rate(pc->clk_pwms[pwm->hwpwm])); cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000, resolution); while (cnt_period > 8191) { resolution *= 2; clkdiv++; cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000, resolution); } if (clkdiv > PWM_CLK_DIV_MAX) { pwm_mediatek_clk_disable(chip, pwm); dev_err(chip->dev, "period %d not supported\n", period_ns); return -EINVAL; } if (pc->soc->pwm45_fixup && pwm->hwpwm > 2) { /* * PWM[4,5] has distinct offset for PWMDWIDTH and PWMTHRES * from the other PWMs on MT7623. */ reg_width = PWM45DWIDTH_FIXUP; reg_thres = PWM45THRES_FIXUP; } cnt_duty = DIV_ROUND_CLOSEST_ULL((u64)duty_ns * 1000, resolution); pwm_mediatek_writel(pc, pwm->hwpwm, PWMCON, BIT(15) | clkdiv); pwm_mediatek_writel(pc, pwm->hwpwm, reg_width, cnt_period); pwm_mediatek_writel(pc, pwm->hwpwm, reg_thres, cnt_duty); pwm_mediatek_clk_disable(chip, pwm); return 0; } static int pwm_mediatek_enable(struct pwm_chip *chip, struct pwm_device *pwm) { struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip); u32 value; int ret; ret = pwm_mediatek_clk_enable(chip, pwm); if (ret < 0) return ret; value = readl(pc->regs); value |= BIT(pwm->hwpwm); writel(value, pc->regs); return 0; } static void pwm_mediatek_disable(struct pwm_chip *chip, struct pwm_device *pwm) { struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip); u32 value; value = readl(pc->regs); value &= ~BIT(pwm->hwpwm); writel(value, pc->regs); pwm_mediatek_clk_disable(chip, pwm); } static const struct pwm_ops pwm_mediatek_ops = { .config = pwm_mediatek_config, .enable = pwm_mediatek_enable, .disable = pwm_mediatek_disable, .owner = THIS_MODULE, }; static int pwm_mediatek_probe(struct platform_device *pdev) { struct pwm_mediatek_chip *pc; struct resource *res; unsigned int i; int ret; pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); if (!pc) return -ENOMEM; pc->soc = of_device_get_match_data(&pdev->dev); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); pc->regs = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(pc->regs)) return PTR_ERR(pc->regs); pc->clk_pwms = devm_kcalloc(&pdev->dev, pc->soc->num_pwms, sizeof(*pc->clk_pwms), GFP_KERNEL); if (!pc->clk_pwms) return -ENOMEM; pc->clk_top = devm_clk_get(&pdev->dev, "top"); if (IS_ERR(pc->clk_top)) { dev_err(&pdev->dev, "clock: top fail: %ld\n", PTR_ERR(pc->clk_top)); return PTR_ERR(pc->clk_top); } pc->clk_main = devm_clk_get(&pdev->dev, "main"); if (IS_ERR(pc->clk_main)) { dev_err(&pdev->dev, "clock: main fail: %ld\n", PTR_ERR(pc->clk_main)); return PTR_ERR(pc->clk_main); } for (i = 0; i < pc->soc->num_pwms; i++) { char name[8]; snprintf(name, sizeof(name), "pwm%d", i + 1); pc->clk_pwms[i] = devm_clk_get(&pdev->dev, name); if (IS_ERR(pc->clk_pwms[i])) { dev_err(&pdev->dev, "clock: %s fail: %ld\n", name, PTR_ERR(pc->clk_pwms[i])); return PTR_ERR(pc->clk_pwms[i]); } } platform_set_drvdata(pdev, pc); pc->chip.dev = &pdev->dev; pc->chip.ops = &pwm_mediatek_ops; pc->chip.base = -1; pc->chip.npwm = pc->soc->num_pwms; ret = pwmchip_add(&pc->chip); if (ret < 0) { dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret); return ret; } return 0; } static int pwm_mediatek_remove(struct platform_device *pdev) { struct pwm_mediatek_chip *pc = platform_get_drvdata(pdev); return pwmchip_remove(&pc->chip); } static const struct pwm_mediatek_of_data mt2712_pwm_data = { .num_pwms = 8, .pwm45_fixup = false, }; static const struct pwm_mediatek_of_data mt7622_pwm_data = { .num_pwms = 6, .pwm45_fixup = false, }; static const struct pwm_mediatek_of_data mt7623_pwm_data = { .num_pwms = 5, .pwm45_fixup = true, }; static const struct pwm_mediatek_of_data mt7628_pwm_data = { .num_pwms = 4, .pwm45_fixup = true, }; static const struct pwm_mediatek_of_data mt7629_pwm_data = { .num_pwms = 1, .pwm45_fixup = false, }; static const struct pwm_mediatek_of_data mt8516_pwm_data = { .num_pwms = 5, .pwm45_fixup = false, }; static const struct of_device_id pwm_mediatek_of_match[] = { { .compatible = "mediatek,mt2712-pwm", .data = &mt2712_pwm_data }, { .compatible = "mediatek,mt7622-pwm", .data = &mt7622_pwm_data }, { .compatible = "mediatek,mt7623-pwm", .data = &mt7623_pwm_data }, { .compatible = "mediatek,mt7628-pwm", .data = &mt7628_pwm_data }, { .compatible = "mediatek,mt7629-pwm", .data = &mt7629_pwm_data }, { .compatible = "mediatek,mt8516-pwm", .data = &mt8516_pwm_data }, { }, }; MODULE_DEVICE_TABLE(of, pwm_mediatek_of_match); static struct platform_driver pwm_mediatek_driver = { .driver = { .name = "pwm-mediatek", .of_match_table = pwm_mediatek_of_match, }, .probe = pwm_mediatek_probe, .remove = pwm_mediatek_remove, }; module_platform_driver(pwm_mediatek_driver); MODULE_AUTHOR("John Crispin <blogic@openwrt.org>"); MODULE_LICENSE("GPL v2");