/* * MediaTek display pulse-width-modulation controller driver. * Copyright (c) 2015 MediaTek Inc. * Author: YH Huang <yh.huang@mediatek.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include <linux/clk.h> #include <linux/err.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/slab.h> #define DISP_PWM_EN 0x00 #define PWM_CLKDIV_SHIFT 16 #define PWM_CLKDIV_MAX 0x3ff #define PWM_CLKDIV_MASK (PWM_CLKDIV_MAX << PWM_CLKDIV_SHIFT) #define PWM_PERIOD_BIT_WIDTH 12 #define PWM_PERIOD_MASK ((1 << PWM_PERIOD_BIT_WIDTH) - 1) #define PWM_HIGH_WIDTH_SHIFT 16 #define PWM_HIGH_WIDTH_MASK (0x1fff << PWM_HIGH_WIDTH_SHIFT) struct mtk_pwm_data { u32 enable_mask; unsigned int con0; u32 con0_sel; unsigned int con1; bool has_commit; unsigned int commit; unsigned int commit_mask; unsigned int bls_debug; u32 bls_debug_mask; }; struct mtk_disp_pwm { struct pwm_chip chip; const struct mtk_pwm_data *data; struct clk *clk_main; struct clk *clk_mm; void __iomem *base; }; static inline struct mtk_disp_pwm *to_mtk_disp_pwm(struct pwm_chip *chip) { return container_of(chip, struct mtk_disp_pwm, chip); } static void mtk_disp_pwm_update_bits(struct mtk_disp_pwm *mdp, u32 offset, u32 mask, u32 data) { void __iomem *address = mdp->base + offset; u32 value; value = readl(address); value &= ~mask; value |= data; writel(value, address); } static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns) { struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip); u32 clk_div, period, high_width, value; u64 div, rate; int err; /* * Find period, high_width and clk_div to suit duty_ns and period_ns. * Calculate proper div value to keep period value in the bound. * * period_ns = 10^9 * (clk_div + 1) * (period + 1) / PWM_CLK_RATE * duty_ns = 10^9 * (clk_div + 1) * high_width / PWM_CLK_RATE * * period = (PWM_CLK_RATE * period_ns) / (10^9 * (clk_div + 1)) - 1 * high_width = (PWM_CLK_RATE * duty_ns) / (10^9 * (clk_div + 1)) */ rate = clk_get_rate(mdp->clk_main); clk_div = div_u64(rate * period_ns, NSEC_PER_SEC) >> PWM_PERIOD_BIT_WIDTH; if (clk_div > PWM_CLKDIV_MAX) return -EINVAL; div = NSEC_PER_SEC * (clk_div + 1); period = div64_u64(rate * period_ns, div); if (period > 0) period--; high_width = div64_u64(rate * duty_ns, div); value = period | (high_width << PWM_HIGH_WIDTH_SHIFT); err = clk_enable(mdp->clk_main); if (err < 0) return err; err = clk_enable(mdp->clk_mm); if (err < 0) { clk_disable(mdp->clk_main); return err; } mtk_disp_pwm_update_bits(mdp, mdp->data->con0, PWM_CLKDIV_MASK, clk_div << PWM_CLKDIV_SHIFT); mtk_disp_pwm_update_bits(mdp, mdp->data->con1, PWM_PERIOD_MASK | PWM_HIGH_WIDTH_MASK, value); if (mdp->data->has_commit) { mtk_disp_pwm_update_bits(mdp, mdp->data->commit, mdp->data->commit_mask, mdp->data->commit_mask); mtk_disp_pwm_update_bits(mdp, mdp->data->commit, mdp->data->commit_mask, 0x0); } clk_disable(mdp->clk_mm); clk_disable(mdp->clk_main); return 0; } static int mtk_disp_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) { struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip); int err; err = clk_enable(mdp->clk_main); if (err < 0) return err; err = clk_enable(mdp->clk_mm); if (err < 0) { clk_disable(mdp->clk_main); return err; } mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask, mdp->data->enable_mask); return 0; } static void mtk_disp_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) { struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip); mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask, 0x0); clk_disable(mdp->clk_mm); clk_disable(mdp->clk_main); } static const struct pwm_ops mtk_disp_pwm_ops = { .config = mtk_disp_pwm_config, .enable = mtk_disp_pwm_enable, .disable = mtk_disp_pwm_disable, .owner = THIS_MODULE, }; static int mtk_disp_pwm_probe(struct platform_device *pdev) { struct mtk_disp_pwm *mdp; struct resource *r; int ret; mdp = devm_kzalloc(&pdev->dev, sizeof(*mdp), GFP_KERNEL); if (!mdp) return -ENOMEM; mdp->data = of_device_get_match_data(&pdev->dev); r = platform_get_resource(pdev, IORESOURCE_MEM, 0); mdp->base = devm_ioremap_resource(&pdev->dev, r); if (IS_ERR(mdp->base)) return PTR_ERR(mdp->base); mdp->clk_main = devm_clk_get(&pdev->dev, "main"); if (IS_ERR(mdp->clk_main)) return PTR_ERR(mdp->clk_main); mdp->clk_mm = devm_clk_get(&pdev->dev, "mm"); if (IS_ERR(mdp->clk_mm)) return PTR_ERR(mdp->clk_mm); ret = clk_prepare(mdp->clk_main); if (ret < 0) return ret; ret = clk_prepare(mdp->clk_mm); if (ret < 0) goto disable_clk_main; mdp->chip.dev = &pdev->dev; mdp->chip.ops = &mtk_disp_pwm_ops; mdp->chip.base = -1; mdp->chip.npwm = 1; ret = pwmchip_add(&mdp->chip); if (ret < 0) { dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret); goto disable_clk_mm; } platform_set_drvdata(pdev, mdp); /* * For MT2701, disable double buffer before writing register * and select manual mode and use PWM_PERIOD/PWM_HIGH_WIDTH. */ if (!mdp->data->has_commit) { mtk_disp_pwm_update_bits(mdp, mdp->data->bls_debug, mdp->data->bls_debug_mask, mdp->data->bls_debug_mask); mtk_disp_pwm_update_bits(mdp, mdp->data->con0, mdp->data->con0_sel, mdp->data->con0_sel); } return 0; disable_clk_mm: clk_unprepare(mdp->clk_mm); disable_clk_main: clk_unprepare(mdp->clk_main); return ret; } static int mtk_disp_pwm_remove(struct platform_device *pdev) { struct mtk_disp_pwm *mdp = platform_get_drvdata(pdev); int ret; ret = pwmchip_remove(&mdp->chip); clk_unprepare(mdp->clk_mm); clk_unprepare(mdp->clk_main); return ret; } static const struct mtk_pwm_data mt2701_pwm_data = { .enable_mask = BIT(16), .con0 = 0xa8, .con0_sel = 0x2, .con1 = 0xac, .has_commit = false, .bls_debug = 0xb0, .bls_debug_mask = 0x3, }; static const struct mtk_pwm_data mt8173_pwm_data = { .enable_mask = BIT(0), .con0 = 0x10, .con0_sel = 0x0, .con1 = 0x14, .has_commit = true, .commit = 0x8, .commit_mask = 0x1, }; static const struct of_device_id mtk_disp_pwm_of_match[] = { { .compatible = "mediatek,mt2701-disp-pwm", .data = &mt2701_pwm_data}, { .compatible = "mediatek,mt6595-disp-pwm", .data = &mt8173_pwm_data}, { .compatible = "mediatek,mt8173-disp-pwm", .data = &mt8173_pwm_data}, { } }; MODULE_DEVICE_TABLE(of, mtk_disp_pwm_of_match); static struct platform_driver mtk_disp_pwm_driver = { .driver = { .name = "mediatek-disp-pwm", .of_match_table = mtk_disp_pwm_of_match, }, .probe = mtk_disp_pwm_probe, .remove = mtk_disp_pwm_remove, }; module_platform_driver(mtk_disp_pwm_driver); MODULE_AUTHOR("YH Huang <yh.huang@mediatek.com>"); MODULE_DESCRIPTION("MediaTek SoC display PWM driver"); MODULE_LICENSE("GPL v2");