drivers/pwm/pwm-mediatek.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * MediaTek Pulse Width Modulator driver
   4  *
   5  * Copyright (C) 2015 John Crispin <blogic@openwrt.org>
   6  * Copyright (C) 2017 Zhi Mao <zhi.mao@mediatek.com>
   7  *
   8  */
   9
  10 #include <linux/err.h>
  11 #include <linux/io.h>
  12 #include <linux/ioport.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/clk.h>
  16 #include <linux/of.h>
  17 #include <linux/of_device.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/pwm.h>
  20 #include <linux/slab.h>
  21 #include <linux/types.h>
  22
  23 /* PWM registers and bits definitions */
  24 #define PWMCON                  0x00
  25 #define PWMHDUR                 0x04
  26 #define PWMLDUR                 0x08
  27 #define PWMGDUR                 0x0c
  28 #define PWMWAVENUM              0x28
  29 #define PWMDWIDTH               0x2c
  30 #define PWM45DWIDTH_FIXUP       0x30
  31 #define PWMTHRES                0x30
  32 #define PWM45THRES_FIXUP        0x34
  33 #define PWM_CK_26M_SEL          0x210
  34
  35 #define PWM_CLK_DIV_MAX         7
  36
  37 struct pwm_mediatek_of_data {
  38         unsigned int num_pwms;
  39         bool pwm45_fixup;
  40         bool has_ck_26m_sel;
  41 };
  42
  43 /**
  44  * struct pwm_mediatek_chip - struct representing PWM chip
  45  * @chip: linux PWM chip representation
  46  * @regs: base address of PWM chip
  47  * @clk_top: the top clock generator
  48  * @clk_main: the clock used by PWM core
  49  * @clk_pwms: the clock used by each PWM channel
  50  * @clk_freq: the fix clock frequency of legacy MIPS SoC
  51  * @soc: pointer to chip's platform data
  52  */
  53 struct pwm_mediatek_chip {
  54         struct pwm_chip chip;
  55         void __iomem *regs;
  56         struct clk *clk_top;
  57         struct clk *clk_main;
  58         struct clk **clk_pwms;
  59         const struct pwm_mediatek_of_data *soc;
  60 };
  61
  62 static const unsigned int pwm_mediatek_reg_offset[] = {
  63         0x0010, 0x0050, 0x0090, 0x00d0, 0x0110, 0x0150, 0x0190, 0x0220
  64 };
  65
  66 static inline struct pwm_mediatek_chip *
  67 to_pwm_mediatek_chip(struct pwm_chip *chip)
  68 {
  69         return container_of(chip, struct pwm_mediatek_chip, chip);
  70 }
  71
  72 static int pwm_mediatek_clk_enable(struct pwm_chip *chip,
  73                                    struct pwm_device *pwm)
  74 {
  75         struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
  76         int ret;
  77
  78         ret = clk_prepare_enable(pc->clk_top);
  79         if (ret < 0)
  80                 return ret;
  81
  82         ret = clk_prepare_enable(pc->clk_main);
  83         if (ret < 0)
  84                 goto disable_clk_top;
  85
  86         ret = clk_prepare_enable(pc->clk_pwms[pwm->hwpwm]);
  87         if (ret < 0)
  88                 goto disable_clk_main;
  89
  90         return 0;
  91
  92 disable_clk_main:
  93         clk_disable_unprepare(pc->clk_main);
  94 disable_clk_top:
  95         clk_disable_unprepare(pc->clk_top);
  96
  97         return ret;
  98 }
  99
 100 static void pwm_mediatek_clk_disable(struct pwm_chip *chip,
 101                                      struct pwm_device *pwm)
 102 {
 103         struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
 104
 105         clk_disable_unprepare(pc->clk_pwms[pwm->hwpwm]);
 106         clk_disable_unprepare(pc->clk_main);
 107         clk_disable_unprepare(pc->clk_top);
 108 }
 109
 110 static inline u32 pwm_mediatek_readl(struct pwm_mediatek_chip *chip,
 111                                      unsigned int num, unsigned int offset)
 112 {
 113         return readl(chip->regs + pwm_mediatek_reg_offset[num] + offset);
 114 }
 115
 116 static inline void pwm_mediatek_writel(struct pwm_mediatek_chip *chip,
 117                                        unsigned int num, unsigned int offset,
 118                                        u32 value)
 119 {
 120         writel(value, chip->regs + pwm_mediatek_reg_offset[num] + offset);
 121 }
 122
 123 static int pwm_mediatek_config(struct pwm_chip *chip, struct pwm_device *pwm,
 124                                int duty_ns, int period_ns)
 125 {
 126         struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
 127         u32 clkdiv = 0, cnt_period, cnt_duty, reg_width = PWMDWIDTH,
 128             reg_thres = PWMTHRES;
 129         u64 resolution;
 130         int ret;
 131
 132         ret = pwm_mediatek_clk_enable(chip, pwm);
 133
 134         if (ret < 0)
 135                 return ret;
 136
 137         /* Make sure we use the bus clock and not the 26MHz clock */
 138         if (pc->soc->has_ck_26m_sel)
 139                 writel(0, pc->regs + PWM_CK_26M_SEL);
 140
 141         /* Using resolution in picosecond gets accuracy higher */
 142         resolution = (u64)NSEC_PER_SEC * 1000;
 143         do_div(resolution, clk_get_rate(pc->clk_pwms[pwm->hwpwm]));
 144
 145         cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000, resolution);
 146         while (cnt_period > 8191) {
 147                 resolution *= 2;
 148                 clkdiv++;
 149                 cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000,
 150                                                    resolution);
 151         }
 152
 153         if (clkdiv > PWM_CLK_DIV_MAX) {
 154                 pwm_mediatek_clk_disable(chip, pwm);
 155                 dev_err(chip->dev, "period %d not supported\n", period_ns);
 156                 return -EINVAL;
 157         }
 158
 159         if (pc->soc->pwm45_fixup && pwm->hwpwm > 2) {
 160                 /*
 161                  * PWM[4,5] has distinct offset for PWMDWIDTH and PWMTHRES
 162                  * from the other PWMs on MT7623.
 163                  */
 164                 reg_width = PWM45DWIDTH_FIXUP;
 165                 reg_thres = PWM45THRES_FIXUP;
 166         }
 167
 168         cnt_duty = DIV_ROUND_CLOSEST_ULL((u64)duty_ns * 1000, resolution);
 169         pwm_mediatek_writel(pc, pwm->hwpwm, PWMCON, BIT(15) | clkdiv);
 170         pwm_mediatek_writel(pc, pwm->hwpwm, reg_width, cnt_period);
 171         pwm_mediatek_writel(pc, pwm->hwpwm, reg_thres, cnt_duty);
 172
 173         pwm_mediatek_clk_disable(chip, pwm);
 174
 175         return 0;
 176 }
 177
 178 static int pwm_mediatek_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 179 {
 180         struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
 181         u32 value;
 182         int ret;
 183
 184         ret = pwm_mediatek_clk_enable(chip, pwm);
 185         if (ret < 0)
 186                 return ret;
 187
 188         value = readl(pc->regs);
 189         value |= BIT(pwm->hwpwm);
 190         writel(value, pc->regs);
 191
 192         return 0;
 193 }
 194
 195 static void pwm_mediatek_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 196 {
 197         struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
 198         u32 value;
 199
 200         value = readl(pc->regs);
 201         value &= ~BIT(pwm->hwpwm);
 202         writel(value, pc->regs);
 203
 204         pwm_mediatek_clk_disable(chip, pwm);
 205 }
 206
 207 static const struct pwm_ops pwm_mediatek_ops = {
 208         .config = pwm_mediatek_config,
 209         .enable = pwm_mediatek_enable,
 210         .disable = pwm_mediatek_disable,
 211         .owner = THIS_MODULE,
 212 };
 213
 214 static int pwm_mediatek_probe(struct platform_device *pdev)
 215 {
 216         struct pwm_mediatek_chip *pc;
 217         unsigned int i;
 218         int ret;
 219
 220         pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
 221         if (!pc)
 222                 return -ENOMEM;
 223
 224         pc->soc = of_device_get_match_data(&pdev->dev);
 225
 226         pc->regs = devm_platform_ioremap_resource(pdev, 0);
 227         if (IS_ERR(pc->regs))
 228                 return PTR_ERR(pc->regs);
 229
 230         pc->clk_pwms = devm_kcalloc(&pdev->dev, pc->soc->num_pwms,
 231                                     sizeof(*pc->clk_pwms), GFP_KERNEL);
 232         if (!pc->clk_pwms)
 233                 return -ENOMEM;
 234
 235         pc->clk_top = devm_clk_get(&pdev->dev, "top");
 236         if (IS_ERR(pc->clk_top)) {
 237                 dev_err(&pdev->dev, "clock: top fail: %ld\n",
 238                         PTR_ERR(pc->clk_top));
 239                 return PTR_ERR(pc->clk_top);
 240         }
 241
 242         pc->clk_main = devm_clk_get(&pdev->dev, "main");
 243         if (IS_ERR(pc->clk_main)) {
 244                 dev_err(&pdev->dev, "clock: main fail: %ld\n",
 245                         PTR_ERR(pc->clk_main));
 246                 return PTR_ERR(pc->clk_main);
 247         }
 248
 249         for (i = 0; i < pc->soc->num_pwms; i++) {
 250                 char name[8];
 251
 252                 snprintf(name, sizeof(name), "pwm%d", i + 1);
 253
 254                 pc->clk_pwms[i] = devm_clk_get(&pdev->dev, name);
 255                 if (IS_ERR(pc->clk_pwms[i])) {
 256                         dev_err(&pdev->dev, "clock: %s fail: %ld\n",
 257                                 name, PTR_ERR(pc->clk_pwms[i]));
 258                         return PTR_ERR(pc->clk_pwms[i]);
 259                 }
 260         }
 261
 262         platform_set_drvdata(pdev, pc);
 263
 264         pc->chip.dev = &pdev->dev;
 265         pc->chip.ops = &pwm_mediatek_ops;
 266         pc->chip.base = -1;
 267         pc->chip.npwm = pc->soc->num_pwms;
 268
 269         ret = pwmchip_add(&pc->chip);
 270         if (ret < 0) {
 271                 dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
 272                 return ret;
 273         }
 274
 275         return 0;
 276 }
 277
 278 static int pwm_mediatek_remove(struct platform_device *pdev)
 279 {
 280         struct pwm_mediatek_chip *pc = platform_get_drvdata(pdev);
 281
 282         return pwmchip_remove(&pc->chip);
 283 }
 284
 285 static const struct pwm_mediatek_of_data mt2712_pwm_data = {
 286         .num_pwms = 8,
 287         .pwm45_fixup = false,
 288         .has_ck_26m_sel = false,
 289 };
 290
 291 static const struct pwm_mediatek_of_data mt7622_pwm_data = {
 292         .num_pwms = 6,
 293         .pwm45_fixup = false,
 294         .has_ck_26m_sel = false,
 295 };
 296
 297 static const struct pwm_mediatek_of_data mt7623_pwm_data = {
 298         .num_pwms = 5,
 299         .pwm45_fixup = true,
 300         .has_ck_26m_sel = false,
 301 };
 302
 303 static const struct pwm_mediatek_of_data mt7628_pwm_data = {
 304         .num_pwms = 4,
 305         .pwm45_fixup = true,
 306         .has_ck_26m_sel = false,
 307 };
 308
 309 static const struct pwm_mediatek_of_data mt7629_pwm_data = {
 310         .num_pwms = 1,
 311         .pwm45_fixup = false,
 312         .has_ck_26m_sel = false,
 313 };
 314
 315 static const struct pwm_mediatek_of_data mt8183_pwm_data = {
 316         .num_pwms = 4,
 317         .pwm45_fixup = false,
 318         .has_ck_26m_sel = true,
 319 };
 320
 321 static const struct pwm_mediatek_of_data mt8516_pwm_data = {
 322         .num_pwms = 5,
 323         .pwm45_fixup = false,
 324         .has_ck_26m_sel = true,
 325 };
 326
 327 static const struct of_device_id pwm_mediatek_of_match[] = {
 328         { .compatible = "mediatek,mt2712-pwm", .data = &mt2712_pwm_data },
 329         { .compatible = "mediatek,mt7622-pwm", .data = &mt7622_pwm_data },
 330         { .compatible = "mediatek,mt7623-pwm", .data = &mt7623_pwm_data },
 331         { .compatible = "mediatek,mt7628-pwm", .data = &mt7628_pwm_data },
 332         { .compatible = "mediatek,mt7629-pwm", .data = &mt7629_pwm_data },
 333         { .compatible = "mediatek,mt8183-pwm", .data = &mt8183_pwm_data },
 334         { .compatible = "mediatek,mt8516-pwm", .data = &mt8516_pwm_data },
 335         { },
 336 };
 337 MODULE_DEVICE_TABLE(of, pwm_mediatek_of_match);
 338
 339 static struct platform_driver pwm_mediatek_driver = {
 340         .driver = {
 341                 .name = "pwm-mediatek",
 342                 .of_match_table = pwm_mediatek_of_match,
 343         },
 344         .probe = pwm_mediatek_probe,
 345         .remove = pwm_mediatek_remove,
 346 };
 347 module_platform_driver(pwm_mediatek_driver);
 348
 349 MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
 350 MODULE_LICENSE("GPL v2");