/* * Imagination Technologies Pulse Width Modulator driver * * Copyright (c) 2014-2015, Imagination Technologies * * Based on drivers/pwm/pwm-tegra.c, Copyright (c) 2010, NVIDIA Corporation * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License. */ #include #include #include #include #include #include #include #include #include #include #include #include /* PWM registers */ #define PWM_CTRL_CFG 0x0000 #define PWM_CTRL_CFG_NO_SUB_DIV 0 #define PWM_CTRL_CFG_SUB_DIV0 1 #define PWM_CTRL_CFG_SUB_DIV1 2 #define PWM_CTRL_CFG_SUB_DIV0_DIV1 3 #define PWM_CTRL_CFG_DIV_SHIFT(ch) ((ch) * 2 + 4) #define PWM_CTRL_CFG_DIV_MASK 0x3 #define PWM_CH_CFG(ch) (0x4 + (ch) * 4) #define PWM_CH_CFG_TMBASE_SHIFT 0 #define PWM_CH_CFG_DUTY_SHIFT 16 #define PERIP_PWM_PDM_CONTROL 0x0140 #define PERIP_PWM_PDM_CONTROL_CH_MASK 0x1 #define PERIP_PWM_PDM_CONTROL_CH_SHIFT(ch) ((ch) * 4) #define IMG_PWM_PM_TIMEOUT 1000 /* ms */ /* * PWM period is specified with a timebase register, * in number of step periods. The PWM duty cycle is also * specified in step periods, in the [0, $timebase] range. * In other words, the timebase imposes the duty cycle * resolution. Therefore, let's constraint the timebase to * a minimum value to allow a sane range of duty cycle values. * Imposing a minimum timebase, will impose a maximum PWM frequency. * * The value chosen is completely arbitrary. */ #define MIN_TMBASE_STEPS 16 #define IMG_PWM_NPWM 4 struct img_pwm_soc_data { u32 max_timebase; }; struct img_pwm_chip { struct device *dev; struct pwm_chip chip; struct clk *pwm_clk; struct clk *sys_clk; void __iomem *base; struct regmap *periph_regs; int max_period_ns; int min_period_ns; const struct img_pwm_soc_data *data; u32 suspend_ctrl_cfg; u32 suspend_ch_cfg[IMG_PWM_NPWM]; }; static inline struct img_pwm_chip *to_img_pwm_chip(struct pwm_chip *chip) { return container_of(chip, struct img_pwm_chip, chip); } static inline void img_pwm_writel(struct img_pwm_chip *chip, u32 reg, u32 val) { writel(val, chip->base + reg); } static inline u32 img_pwm_readl(struct img_pwm_chip *chip, u32 reg) { return readl(chip->base + reg); } static int img_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns) { u32 val, div, duty, timebase; unsigned long mul, output_clk_hz, input_clk_hz; struct img_pwm_chip *pwm_chip = to_img_pwm_chip(chip); unsigned int max_timebase = pwm_chip->data->max_timebase; int ret; if (period_ns < pwm_chip->min_period_ns || period_ns > pwm_chip->max_period_ns) { dev_err(chip->dev, "configured period not in range\n"); return -ERANGE; } input_clk_hz = clk_get_rate(pwm_chip->pwm_clk); output_clk_hz = DIV_ROUND_UP(NSEC_PER_SEC, period_ns); mul = DIV_ROUND_UP(input_clk_hz, output_clk_hz); if (mul <= max_timebase) { div = PWM_CTRL_CFG_NO_SUB_DIV; timebase = DIV_ROUND_UP(mul, 1); } else if (mul <= max_timebase * 8) { div = PWM_CTRL_CFG_SUB_DIV0; timebase = DIV_ROUND_UP(mul, 8); } else if (mul <= max_timebase * 64) { div = PWM_CTRL_CFG_SUB_DIV1; timebase = DIV_ROUND_UP(mul, 64); } else if (mul <= max_timebase * 512) { div = PWM_CTRL_CFG_SUB_DIV0_DIV1; timebase = DIV_ROUND_UP(mul, 512); } else if (mul > max_timebase * 512) { dev_err(chip->dev, "failed to configure timebase steps/divider value\n"); return -EINVAL; } duty = DIV_ROUND_UP(timebase * duty_ns, period_ns); ret = pm_runtime_get_sync(chip->dev); if (ret < 0) { pm_runtime_put_autosuspend(chip->dev); return ret; } val = img_pwm_readl(pwm_chip, PWM_CTRL_CFG); val &= ~(PWM_CTRL_CFG_DIV_MASK << PWM_CTRL_CFG_DIV_SHIFT(pwm->hwpwm)); val |= (div & PWM_CTRL_CFG_DIV_MASK) << PWM_CTRL_CFG_DIV_SHIFT(pwm->hwpwm); img_pwm_writel(pwm_chip, PWM_CTRL_CFG, val); val = (duty << PWM_CH_CFG_DUTY_SHIFT) | (timebase << PWM_CH_CFG_TMBASE_SHIFT); img_pwm_writel(pwm_chip, PWM_CH_CFG(pwm->hwpwm), val); pm_runtime_mark_last_busy(chip->dev); pm_runtime_put_autosuspend(chip->dev); return 0; } static int img_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) { u32 val; struct img_pwm_chip *pwm_chip = to_img_pwm_chip(chip); int ret; ret = pm_runtime_get_sync(chip->dev); if (ret < 0) return ret; val = img_pwm_readl(pwm_chip, PWM_CTRL_CFG); val |= BIT(pwm->hwpwm); img_pwm_writel(pwm_chip, PWM_CTRL_CFG, val); regmap_update_bits(pwm_chip->periph_regs, PERIP_PWM_PDM_CONTROL, PERIP_PWM_PDM_CONTROL_CH_MASK << PERIP_PWM_PDM_CONTROL_CH_SHIFT(pwm->hwpwm), 0); return 0; } static void img_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) { u32 val; struct img_pwm_chip *pwm_chip = to_img_pwm_chip(chip); val = img_pwm_readl(pwm_chip, PWM_CTRL_CFG); val &= ~BIT(pwm->hwpwm); img_pwm_writel(pwm_chip, PWM_CTRL_CFG, val); pm_runtime_mark_last_busy(chip->dev); pm_runtime_put_autosuspend(chip->dev); } static const struct pwm_ops img_pwm_ops = { .config = img_pwm_config, .enable = img_pwm_enable, .disable = img_pwm_disable, .owner = THIS_MODULE, }; static const struct img_pwm_soc_data pistachio_pwm = { .max_timebase = 255, }; static const struct of_device_id img_pwm_of_match[] = { { .compatible = "img,pistachio-pwm", .data = &pistachio_pwm, }, { } }; MODULE_DEVICE_TABLE(of, img_pwm_of_match); static int img_pwm_runtime_suspend(struct device *dev) { struct img_pwm_chip *pwm_chip = dev_get_drvdata(dev); clk_disable_unprepare(pwm_chip->pwm_clk); clk_disable_unprepare(pwm_chip->sys_clk); return 0; } static int img_pwm_runtime_resume(struct device *dev) { struct img_pwm_chip *pwm_chip = dev_get_drvdata(dev); int ret; ret = clk_prepare_enable(pwm_chip->sys_clk); if (ret < 0) { dev_err(dev, "could not prepare or enable sys clock\n"); return ret; } ret = clk_prepare_enable(pwm_chip->pwm_clk); if (ret < 0) { dev_err(dev, "could not prepare or enable pwm clock\n"); clk_disable_unprepare(pwm_chip->sys_clk); return ret; } return 0; } static int img_pwm_probe(struct platform_device *pdev) { int ret; u64 val; unsigned long clk_rate; struct resource *res; struct img_pwm_chip *pwm; const struct of_device_id *of_dev_id; pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL); if (!pwm) return -ENOMEM; pwm->dev = &pdev->dev; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); pwm->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(pwm->base)) return PTR_ERR(pwm->base); of_dev_id = of_match_device(img_pwm_of_match, &pdev->dev); if (!of_dev_id) return -ENODEV; pwm->data = of_dev_id->data; pwm->periph_regs = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "img,cr-periph"); if (IS_ERR(pwm->periph_regs)) return PTR_ERR(pwm->periph_regs); pwm->sys_clk = devm_clk_get(&pdev->dev, "sys"); if (IS_ERR(pwm->sys_clk)) { dev_err(&pdev->dev, "failed to get system clock\n"); return PTR_ERR(pwm->sys_clk); } pwm->pwm_clk = devm_clk_get(&pdev->dev, "pwm"); if (IS_ERR(pwm->pwm_clk)) { dev_err(&pdev->dev, "failed to get pwm clock\n"); return PTR_ERR(pwm->pwm_clk); } platform_set_drvdata(pdev, pwm); pm_runtime_set_autosuspend_delay(&pdev->dev, IMG_PWM_PM_TIMEOUT); pm_runtime_use_autosuspend(&pdev->dev); pm_runtime_enable(&pdev->dev); if (!pm_runtime_enabled(&pdev->dev)) { ret = img_pwm_runtime_resume(&pdev->dev); if (ret) goto err_pm_disable; } clk_rate = clk_get_rate(pwm->pwm_clk); if (!clk_rate) { dev_err(&pdev->dev, "pwm clock has no frequency\n"); ret = -EINVAL; goto err_suspend; } /* The maximum input clock divider is 512 */ val = (u64)NSEC_PER_SEC * 512 * pwm->data->max_timebase; do_div(val, clk_rate); pwm->max_period_ns = val; val = (u64)NSEC_PER_SEC * MIN_TMBASE_STEPS; do_div(val, clk_rate); pwm->min_period_ns = val; pwm->chip.dev = &pdev->dev; pwm->chip.ops = &img_pwm_ops; pwm->chip.base = -1; pwm->chip.npwm = IMG_PWM_NPWM; ret = pwmchip_add(&pwm->chip); if (ret < 0) { dev_err(&pdev->dev, "pwmchip_add failed: %d\n", ret); goto err_suspend; } return 0; err_suspend: if (!pm_runtime_enabled(&pdev->dev)) img_pwm_runtime_suspend(&pdev->dev); err_pm_disable: pm_runtime_disable(&pdev->dev); pm_runtime_dont_use_autosuspend(&pdev->dev); return ret; } static int img_pwm_remove(struct platform_device *pdev) { struct img_pwm_chip *pwm_chip = platform_get_drvdata(pdev); u32 val; unsigned int i; int ret; ret = pm_runtime_get_sync(&pdev->dev); if (ret < 0) { pm_runtime_put(&pdev->dev); return ret; } for (i = 0; i < pwm_chip->chip.npwm; i++) { val = img_pwm_readl(pwm_chip, PWM_CTRL_CFG); val &= ~BIT(i); img_pwm_writel(pwm_chip, PWM_CTRL_CFG, val); } pm_runtime_put(&pdev->dev); pm_runtime_disable(&pdev->dev); if (!pm_runtime_status_suspended(&pdev->dev)) img_pwm_runtime_suspend(&pdev->dev); return pwmchip_remove(&pwm_chip->chip); } #ifdef CONFIG_PM_SLEEP static int img_pwm_suspend(struct device *dev) { struct img_pwm_chip *pwm_chip = dev_get_drvdata(dev); int i, ret; if (pm_runtime_status_suspended(dev)) { ret = img_pwm_runtime_resume(dev); if (ret) return ret; } for (i = 0; i < pwm_chip->chip.npwm; i++) pwm_chip->suspend_ch_cfg[i] = img_pwm_readl(pwm_chip, PWM_CH_CFG(i)); pwm_chip->suspend_ctrl_cfg = img_pwm_readl(pwm_chip, PWM_CTRL_CFG); img_pwm_runtime_suspend(dev); return 0; } static int img_pwm_resume(struct device *dev) { struct img_pwm_chip *pwm_chip = dev_get_drvdata(dev); int ret; int i; ret = img_pwm_runtime_resume(dev); if (ret) return ret; for (i = 0; i < pwm_chip->chip.npwm; i++) img_pwm_writel(pwm_chip, PWM_CH_CFG(i), pwm_chip->suspend_ch_cfg[i]); img_pwm_writel(pwm_chip, PWM_CTRL_CFG, pwm_chip->suspend_ctrl_cfg); for (i = 0; i < pwm_chip->chip.npwm; i++) if (pwm_chip->suspend_ctrl_cfg & BIT(i)) regmap_update_bits(pwm_chip->periph_regs, PERIP_PWM_PDM_CONTROL, PERIP_PWM_PDM_CONTROL_CH_MASK << PERIP_PWM_PDM_CONTROL_CH_SHIFT(i), 0); if (pm_runtime_status_suspended(dev)) img_pwm_runtime_suspend(dev); return 0; } #endif /* CONFIG_PM */ static const struct dev_pm_ops img_pwm_pm_ops = { SET_RUNTIME_PM_OPS(img_pwm_runtime_suspend, img_pwm_runtime_resume, NULL) SET_SYSTEM_SLEEP_PM_OPS(img_pwm_suspend, img_pwm_resume) }; static struct platform_driver img_pwm_driver = { .driver = { .name = "img-pwm", .pm = &img_pwm_pm_ops, .of_match_table = img_pwm_of_match, }, .probe = img_pwm_probe, .remove = img_pwm_remove, }; module_platform_driver(img_pwm_driver); MODULE_AUTHOR("Sai Masarapu "); MODULE_DESCRIPTION("Imagination Technologies PWM DAC driver"); MODULE_LICENSE("GPL v2");