drivers/pwm/pwm-mtk-disp.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * MediaTek display pulse-width-modulation controller driver.
   4  * Copyright (c) 2015 MediaTek Inc.
   5  * Author: YH Huang <yh.huang@mediatek.com>
   6  */
   7
   8 #include <linux/clk.h>
   9 #include <linux/err.h>
  10 #include <linux/io.h>
  11 #include <linux/module.h>
  12 #include <linux/of.h>
  13 #include <linux/of_device.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/pwm.h>
  16 #include <linux/slab.h>
  17
  18 #define DISP_PWM_EN             0x00
  19
  20 #define PWM_CLKDIV_SHIFT        16
  21 #define PWM_CLKDIV_MAX          0x3ff
  22 #define PWM_CLKDIV_MASK         (PWM_CLKDIV_MAX << PWM_CLKDIV_SHIFT)
  23
  24 #define PWM_PERIOD_BIT_WIDTH    12
  25 #define PWM_PERIOD_MASK         ((1 << PWM_PERIOD_BIT_WIDTH) - 1)
  26
  27 #define PWM_HIGH_WIDTH_SHIFT    16
  28 #define PWM_HIGH_WIDTH_MASK     (0x1fff << PWM_HIGH_WIDTH_SHIFT)
  29
  30 struct mtk_pwm_data {
  31         u32 enable_mask;
  32         unsigned int con0;
  33         u32 con0_sel;
  34         unsigned int con1;
  35
  36         bool has_commit;
  37         unsigned int commit;
  38         unsigned int commit_mask;
  39
  40         unsigned int bls_debug;
  41         u32 bls_debug_mask;
  42 };
  43
  44 struct mtk_disp_pwm {
  45         struct pwm_chip chip;
  46         const struct mtk_pwm_data *data;
  47         struct clk *clk_main;
  48         struct clk *clk_mm;
  49         void __iomem *base;
  50 };
  51
  52 static inline struct mtk_disp_pwm *to_mtk_disp_pwm(struct pwm_chip *chip)
  53 {
  54         return container_of(chip, struct mtk_disp_pwm, chip);
  55 }
  56
  57 static void mtk_disp_pwm_update_bits(struct mtk_disp_pwm *mdp, u32 offset,
  58                                      u32 mask, u32 data)
  59 {
  60         void __iomem *address = mdp->base + offset;
  61         u32 value;
  62
  63         value = readl(address);
  64         value &= ~mask;
  65         value |= data;
  66         writel(value, address);
  67 }
  68
  69 static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
  70                                int duty_ns, int period_ns)
  71 {
  72         struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
  73         u32 clk_div, period, high_width, value;
  74         u64 div, rate;
  75         int err;
  76
  77         /*
  78          * Find period, high_width and clk_div to suit duty_ns and period_ns.
  79          * Calculate proper div value to keep period value in the bound.
  80          *
  81          * period_ns = 10^9 * (clk_div + 1) * (period + 1) / PWM_CLK_RATE
  82          * duty_ns = 10^9 * (clk_div + 1) * high_width / PWM_CLK_RATE
  83          *
  84          * period = (PWM_CLK_RATE * period_ns) / (10^9 * (clk_div + 1)) - 1
  85          * high_width = (PWM_CLK_RATE * duty_ns) / (10^9 * (clk_div + 1))
  86          */
  87         rate = clk_get_rate(mdp->clk_main);
  88         clk_div = div_u64(rate * period_ns, NSEC_PER_SEC) >>
  89                           PWM_PERIOD_BIT_WIDTH;
  90         if (clk_div > PWM_CLKDIV_MAX)
  91                 return -EINVAL;
  92
  93         div = NSEC_PER_SEC * (clk_div + 1);
  94         period = div64_u64(rate * period_ns, div);
  95         if (period > 0)
  96                 period--;
  97
  98         high_width = div64_u64(rate * duty_ns, div);
  99         value = period | (high_width << PWM_HIGH_WIDTH_SHIFT);
 100
 101         err = clk_enable(mdp->clk_main);
 102         if (err < 0)
 103                 return err;
 104
 105         err = clk_enable(mdp->clk_mm);
 106         if (err < 0) {
 107                 clk_disable(mdp->clk_main);
 108                 return err;
 109         }
 110
 111         mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
 112                                  PWM_CLKDIV_MASK,
 113                                  clk_div << PWM_CLKDIV_SHIFT);
 114         mtk_disp_pwm_update_bits(mdp, mdp->data->con1,
 115                                  PWM_PERIOD_MASK | PWM_HIGH_WIDTH_MASK,
 116                                  value);
 117
 118         if (mdp->data->has_commit) {
 119                 mtk_disp_pwm_update_bits(mdp, mdp->data->commit,
 120                                          mdp->data->commit_mask,
 121                                          mdp->data->commit_mask);
 122                 mtk_disp_pwm_update_bits(mdp, mdp->data->commit,
 123                                          mdp->data->commit_mask,
 124                                          0x0);
 125         }
 126
 127         clk_disable(mdp->clk_mm);
 128         clk_disable(mdp->clk_main);
 129
 130         return 0;
 131 }
 132
 133 static int mtk_disp_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 134 {
 135         struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
 136         int err;
 137
 138         err = clk_enable(mdp->clk_main);
 139         if (err < 0)
 140                 return err;
 141
 142         err = clk_enable(mdp->clk_mm);
 143         if (err < 0) {
 144                 clk_disable(mdp->clk_main);
 145                 return err;
 146         }
 147
 148         mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
 149                                  mdp->data->enable_mask);
 150
 151         return 0;
 152 }
 153
 154 static void mtk_disp_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 155 {
 156         struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
 157
 158         mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
 159                                  0x0);
 160
 161         clk_disable(mdp->clk_mm);
 162         clk_disable(mdp->clk_main);
 163 }
 164
 165 static const struct pwm_ops mtk_disp_pwm_ops = {
 166         .config = mtk_disp_pwm_config,
 167         .enable = mtk_disp_pwm_enable,
 168         .disable = mtk_disp_pwm_disable,
 169         .owner = THIS_MODULE,
 170 };
 171
 172 static int mtk_disp_pwm_probe(struct platform_device *pdev)
 173 {
 174         struct mtk_disp_pwm *mdp;
 175         struct resource *r;
 176         int ret;
 177
 178         mdp = devm_kzalloc(&pdev->dev, sizeof(*mdp), GFP_KERNEL);
 179         if (!mdp)
 180                 return -ENOMEM;
 181
 182         mdp->data = of_device_get_match_data(&pdev->dev);
 183
 184         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 185         mdp->base = devm_ioremap_resource(&pdev->dev, r);
 186         if (IS_ERR(mdp->base))
 187                 return PTR_ERR(mdp->base);
 188
 189         mdp->clk_main = devm_clk_get(&pdev->dev, "main");
 190         if (IS_ERR(mdp->clk_main))
 191                 return PTR_ERR(mdp->clk_main);
 192
 193         mdp->clk_mm = devm_clk_get(&pdev->dev, "mm");
 194         if (IS_ERR(mdp->clk_mm))
 195                 return PTR_ERR(mdp->clk_mm);
 196
 197         ret = clk_prepare(mdp->clk_main);
 198         if (ret < 0)
 199                 return ret;
 200
 201         ret = clk_prepare(mdp->clk_mm);
 202         if (ret < 0)
 203                 goto disable_clk_main;
 204
 205         mdp->chip.dev = &pdev->dev;
 206         mdp->chip.ops = &mtk_disp_pwm_ops;
 207         mdp->chip.base = -1;
 208         mdp->chip.npwm = 1;
 209
 210         ret = pwmchip_add(&mdp->chip);
 211         if (ret < 0) {
 212                 dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
 213                 goto disable_clk_mm;
 214         }
 215
 216         platform_set_drvdata(pdev, mdp);
 217
 218         /*
 219          * For MT2701, disable double buffer before writing register
 220          * and select manual mode and use PWM_PERIOD/PWM_HIGH_WIDTH.
 221          */
 222         if (!mdp->data->has_commit) {
 223                 mtk_disp_pwm_update_bits(mdp, mdp->data->bls_debug,
 224                                          mdp->data->bls_debug_mask,
 225                                          mdp->data->bls_debug_mask);
 226                 mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
 227                                          mdp->data->con0_sel,
 228                                          mdp->data->con0_sel);
 229         }
 230
 231         return 0;
 232
 233 disable_clk_mm:
 234         clk_unprepare(mdp->clk_mm);
 235 disable_clk_main:
 236         clk_unprepare(mdp->clk_main);
 237         return ret;
 238 }
 239
 240 static int mtk_disp_pwm_remove(struct platform_device *pdev)
 241 {
 242         struct mtk_disp_pwm *mdp = platform_get_drvdata(pdev);
 243         int ret;
 244
 245         ret = pwmchip_remove(&mdp->chip);
 246         clk_unprepare(mdp->clk_mm);
 247         clk_unprepare(mdp->clk_main);
 248
 249         return ret;
 250 }
 251
 252 static const struct mtk_pwm_data mt2701_pwm_data = {
 253         .enable_mask = BIT(16),
 254         .con0 = 0xa8,
 255         .con0_sel = 0x2,
 256         .con1 = 0xac,
 257         .has_commit = false,
 258         .bls_debug = 0xb0,
 259         .bls_debug_mask = 0x3,
 260 };
 261
 262 static const struct mtk_pwm_data mt8173_pwm_data = {
 263         .enable_mask = BIT(0),
 264         .con0 = 0x10,
 265         .con0_sel = 0x0,
 266         .con1 = 0x14,
 267         .has_commit = true,
 268         .commit = 0x8,
 269         .commit_mask = 0x1,
 270 };
 271
 272 static const struct mtk_pwm_data mt8183_pwm_data = {
 273         .enable_mask = BIT(0),
 274         .con0 = 0x18,
 275         .con0_sel = 0x0,
 276         .con1 = 0x1c,
 277         .has_commit = false,
 278         .bls_debug = 0x80,
 279         .bls_debug_mask = 0x3,
 280 };
 281
 282 static const struct of_device_id mtk_disp_pwm_of_match[] = {
 283         { .compatible = "mediatek,mt2701-disp-pwm", .data = &mt2701_pwm_data},
 284         { .compatible = "mediatek,mt6595-disp-pwm", .data = &mt8173_pwm_data},
 285         { .compatible = "mediatek,mt8173-disp-pwm", .data = &mt8173_pwm_data},
 286         { .compatible = "mediatek,mt8183-disp-pwm", .data = &mt8183_pwm_data},
 287         { }
 288 };
 289 MODULE_DEVICE_TABLE(of, mtk_disp_pwm_of_match);
 290
 291 static struct platform_driver mtk_disp_pwm_driver = {
 292         .driver = {
 293                 .name = "mediatek-disp-pwm",
 294                 .of_match_table = mtk_disp_pwm_of_match,
 295         },
 296         .probe = mtk_disp_pwm_probe,
 297         .remove = mtk_disp_pwm_remove,
 298 };
 299 module_platform_driver(mtk_disp_pwm_driver);
 300
 301 MODULE_AUTHOR("YH Huang <yh.huang@mediatek.com>");
 302 MODULE_DESCRIPTION("MediaTek SoC display PWM driver");
 303 MODULE_LICENSE("GPL v2");