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/platform_device.h>
  18 #include <linux/pwm.h>
  19 #include <linux/slab.h>
  20 #include <linux/types.h>
  21
  22 /* PWM registers and bits definitions */
  23 #define PWMCON                  0x00
  24 #define PWMHDUR                 0x04
  25 #define PWMLDUR                 0x08
  26 #define PWMGDUR                 0x0c
  27 #define PWMWAVENUM              0x28
  28 #define PWMDWIDTH               0x2c
  29 #define PWM45DWIDTH_FIXUP       0x30
  30 #define PWMTHRES                0x30
  31 #define PWM45THRES_FIXUP        0x34
  32 #define PWM_CK_26M_SEL          0x210
  33
  34 #define PWM_CLK_DIV_MAX         7
  35
  36 struct pwm_mediatek_of_data {
  37         unsigned int num_pwms;
  38         bool pwm45_fixup;
  39         bool has_ck_26m_sel;
  40         const unsigned int *reg_offset;
  41 };
  42
  43 /**
  44  * struct pwm_mediatek_chip - struct representing PWM chip
  45  * @regs: base address of PWM chip
  46  * @clk_top: the top clock generator
  47  * @clk_main: the clock used by PWM core
  48  * @clk_pwms: the clock used by each PWM channel
  49  * @soc: pointer to chip's platform data
  50  */
  51 struct pwm_mediatek_chip {
  52         void __iomem *regs;
  53         struct clk *clk_top;
  54         struct clk *clk_main;
  55         struct clk **clk_pwms;
  56         const struct pwm_mediatek_of_data *soc;
  57 };
  58
  59 static const unsigned int mtk_pwm_reg_offset_v1[] = {
  60         0x0010, 0x0050, 0x0090, 0x00d0, 0x0110, 0x0150, 0x0190, 0x0220
  61 };
  62
  63 static const unsigned int mtk_pwm_reg_offset_v2[] = {
  64         0x0080, 0x00c0, 0x0100, 0x0140, 0x0180, 0x01c0, 0x0200, 0x0240
  65 };
  66
  67 static inline struct pwm_mediatek_chip *
  68 to_pwm_mediatek_chip(struct pwm_chip *chip)
  69 {
  70         return pwmchip_get_drvdata(chip);
  71 }
  72
  73 static int pwm_mediatek_clk_enable(struct pwm_chip *chip,
  74                                    struct pwm_device *pwm)
  75 {
  76         struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
  77         int ret;
  78
  79         ret = clk_prepare_enable(pc->clk_top);
  80         if (ret < 0)
  81                 return ret;
  82
  83         ret = clk_prepare_enable(pc->clk_main);
  84         if (ret < 0)
  85                 goto disable_clk_top;
  86
  87         ret = clk_prepare_enable(pc->clk_pwms[pwm->hwpwm]);
  88         if (ret < 0)
  89                 goto disable_clk_main;
  90
  91         return 0;
  92
  93 disable_clk_main:
  94         clk_disable_unprepare(pc->clk_main);
  95 disable_clk_top:
  96         clk_disable_unprepare(pc->clk_top);
  97
  98         return ret;
  99 }
 100
 101 static void pwm_mediatek_clk_disable(struct pwm_chip *chip,
 102                                      struct pwm_device *pwm)
 103 {
 104         struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
 105
 106         clk_disable_unprepare(pc->clk_pwms[pwm->hwpwm]);
 107         clk_disable_unprepare(pc->clk_main);
 108         clk_disable_unprepare(pc->clk_top);
 109 }
 110
 111 static inline void pwm_mediatek_writel(struct pwm_mediatek_chip *chip,
 112                                        unsigned int num, unsigned int offset,
 113                                        u32 value)
 114 {
 115         writel(value, chip->regs + chip->soc->reg_offset[num] + offset);
 116 }
 117
 118 static int pwm_mediatek_config(struct pwm_chip *chip, struct pwm_device *pwm,
 119                                int duty_ns, int period_ns)
 120 {
 121         struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
 122         u32 clkdiv = 0, cnt_period, cnt_duty, reg_width = PWMDWIDTH,
 123             reg_thres = PWMTHRES;
 124         u64 resolution;
 125         int ret;
 126
 127         ret = pwm_mediatek_clk_enable(chip, pwm);
 128
 129         if (ret < 0)
 130                 return ret;
 131
 132         /* Make sure we use the bus clock and not the 26MHz clock */
 133         if (pc->soc->has_ck_26m_sel)
 134                 writel(0, pc->regs + PWM_CK_26M_SEL);
 135
 136         /* Using resolution in picosecond gets accuracy higher */
 137         resolution = (u64)NSEC_PER_SEC * 1000;
 138         do_div(resolution, clk_get_rate(pc->clk_pwms[pwm->hwpwm]));
 139
 140         cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000, resolution);
 141         while (cnt_period > 8191) {
 142                 resolution *= 2;
 143                 clkdiv++;
 144                 cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000,
 145                                                    resolution);
 146         }
 147
 148         if (clkdiv > PWM_CLK_DIV_MAX) {
 149                 pwm_mediatek_clk_disable(chip, pwm);
 150                 dev_err(pwmchip_parent(chip), "period of %d ns not supported\n", period_ns);
 151                 return -EINVAL;
 152         }
 153
 154         if (pc->soc->pwm45_fixup && pwm->hwpwm > 2) {
 155                 /*
 156                  * PWM[4,5] has distinct offset for PWMDWIDTH and PWMTHRES
 157                  * from the other PWMs on MT7623.
 158                  */
 159                 reg_width = PWM45DWIDTH_FIXUP;
 160                 reg_thres = PWM45THRES_FIXUP;
 161         }
 162
 163         cnt_duty = DIV_ROUND_CLOSEST_ULL((u64)duty_ns * 1000, resolution);
 164         pwm_mediatek_writel(pc, pwm->hwpwm, PWMCON, BIT(15) | clkdiv);
 165         pwm_mediatek_writel(pc, pwm->hwpwm, reg_width, cnt_period);
 166         pwm_mediatek_writel(pc, pwm->hwpwm, reg_thres, cnt_duty);
 167
 168         pwm_mediatek_clk_disable(chip, pwm);
 169
 170         return 0;
 171 }
 172
 173 static int pwm_mediatek_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 174 {
 175         struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
 176         u32 value;
 177         int ret;
 178
 179         ret = pwm_mediatek_clk_enable(chip, pwm);
 180         if (ret < 0)
 181                 return ret;
 182
 183         value = readl(pc->regs);
 184         value |= BIT(pwm->hwpwm);
 185         writel(value, pc->regs);
 186
 187         return 0;
 188 }
 189
 190 static void pwm_mediatek_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 191 {
 192         struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
 193         u32 value;
 194
 195         value = readl(pc->regs);
 196         value &= ~BIT(pwm->hwpwm);
 197         writel(value, pc->regs);
 198
 199         pwm_mediatek_clk_disable(chip, pwm);
 200 }
 201
 202 static int pwm_mediatek_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 203                               const struct pwm_state *state)
 204 {
 205         int err;
 206
 207         if (state->polarity != PWM_POLARITY_NORMAL)
 208                 return -EINVAL;
 209
 210         if (!state->enabled) {
 211                 if (pwm->state.enabled)
 212                         pwm_mediatek_disable(chip, pwm);
 213
 214                 return 0;
 215         }
 216
 217         err = pwm_mediatek_config(chip, pwm, state->duty_cycle, state->period);
 218         if (err)
 219                 return err;
 220
 221         if (!pwm->state.enabled)
 222                 err = pwm_mediatek_enable(chip, pwm);
 223
 224         return err;
 225 }
 226
 227 static const struct pwm_ops pwm_mediatek_ops = {
 228         .apply = pwm_mediatek_apply,
 229 };
 230
 231 static int pwm_mediatek_probe(struct platform_device *pdev)
 232 {
 233         struct pwm_chip *chip;
 234         struct pwm_mediatek_chip *pc;
 235         const struct pwm_mediatek_of_data *soc;
 236         unsigned int i;
 237         int ret;
 238
 239         soc = of_device_get_match_data(&pdev->dev);
 240
 241         chip = devm_pwmchip_alloc(&pdev->dev, soc->num_pwms, sizeof(*pc));
 242         if (IS_ERR(chip))
 243                 return PTR_ERR(chip);
 244         pc = to_pwm_mediatek_chip(chip);
 245
 246         pc->soc = soc;
 247
 248         pc->regs = devm_platform_ioremap_resource(pdev, 0);
 249         if (IS_ERR(pc->regs))
 250                 return PTR_ERR(pc->regs);
 251
 252         pc->clk_pwms = devm_kmalloc_array(&pdev->dev, soc->num_pwms,
 253                                     sizeof(*pc->clk_pwms), GFP_KERNEL);
 254         if (!pc->clk_pwms)
 255                 return -ENOMEM;
 256
 257         pc->clk_top = devm_clk_get(&pdev->dev, "top");
 258         if (IS_ERR(pc->clk_top))
 259                 return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk_top),
 260                                      "Failed to get top clock\n");
 261
 262         pc->clk_main = devm_clk_get(&pdev->dev, "main");
 263         if (IS_ERR(pc->clk_main))
 264                 return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk_main),
 265                                      "Failed to get main clock\n");
 266
 267         for (i = 0; i < soc->num_pwms; i++) {
 268                 char name[8];
 269
 270                 snprintf(name, sizeof(name), "pwm%d", i + 1);
 271
 272                 pc->clk_pwms[i] = devm_clk_get(&pdev->dev, name);
 273                 if (IS_ERR(pc->clk_pwms[i]))
 274                         return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk_pwms[i]),
 275                                              "Failed to get %s clock\n", name);
 276         }
 277
 278         chip->ops = &pwm_mediatek_ops;
 279
 280         ret = devm_pwmchip_add(&pdev->dev, chip);
 281         if (ret < 0)
 282                 return dev_err_probe(&pdev->dev, ret, "pwmchip_add() failed\n");
 283
 284         return 0;
 285 }
 286
 287 static const struct pwm_mediatek_of_data mt2712_pwm_data = {
 288         .num_pwms = 8,
 289         .pwm45_fixup = false,
 290         .has_ck_26m_sel = false,
 291         .reg_offset = mtk_pwm_reg_offset_v1,
 292 };
 293
 294 static const struct pwm_mediatek_of_data mt6795_pwm_data = {
 295         .num_pwms = 7,
 296         .pwm45_fixup = false,
 297         .has_ck_26m_sel = false,
 298         .reg_offset = mtk_pwm_reg_offset_v1,
 299 };
 300
 301 static const struct pwm_mediatek_of_data mt7622_pwm_data = {
 302         .num_pwms = 6,
 303         .pwm45_fixup = false,
 304         .has_ck_26m_sel = true,
 305         .reg_offset = mtk_pwm_reg_offset_v1,
 306 };
 307
 308 static const struct pwm_mediatek_of_data mt7623_pwm_data = {
 309         .num_pwms = 5,
 310         .pwm45_fixup = true,
 311         .has_ck_26m_sel = false,
 312         .reg_offset = mtk_pwm_reg_offset_v1,
 313 };
 314
 315 static const struct pwm_mediatek_of_data mt7628_pwm_data = {
 316         .num_pwms = 4,
 317         .pwm45_fixup = true,
 318         .has_ck_26m_sel = false,
 319         .reg_offset = mtk_pwm_reg_offset_v1,
 320 };
 321
 322 static const struct pwm_mediatek_of_data mt7629_pwm_data = {
 323         .num_pwms = 1,
 324         .pwm45_fixup = false,
 325         .has_ck_26m_sel = false,
 326         .reg_offset = mtk_pwm_reg_offset_v1,
 327 };
 328
 329 static const struct pwm_mediatek_of_data mt7981_pwm_data = {
 330         .num_pwms = 3,
 331         .pwm45_fixup = false,
 332         .has_ck_26m_sel = true,
 333         .reg_offset = mtk_pwm_reg_offset_v2,
 334 };
 335
 336 static const struct pwm_mediatek_of_data mt7986_pwm_data = {
 337         .num_pwms = 2,
 338         .pwm45_fixup = false,
 339         .has_ck_26m_sel = true,
 340         .reg_offset = mtk_pwm_reg_offset_v1,
 341 };
 342
 343 static const struct pwm_mediatek_of_data mt7988_pwm_data = {
 344         .num_pwms = 8,
 345         .pwm45_fixup = false,
 346         .has_ck_26m_sel = false,
 347         .reg_offset = mtk_pwm_reg_offset_v2,
 348 };
 349
 350 static const struct pwm_mediatek_of_data mt8183_pwm_data = {
 351         .num_pwms = 4,
 352         .pwm45_fixup = false,
 353         .has_ck_26m_sel = true,
 354         .reg_offset = mtk_pwm_reg_offset_v1,
 355 };
 356
 357 static const struct pwm_mediatek_of_data mt8365_pwm_data = {
 358         .num_pwms = 3,
 359         .pwm45_fixup = false,
 360         .has_ck_26m_sel = true,
 361         .reg_offset = mtk_pwm_reg_offset_v1,
 362 };
 363
 364 static const struct pwm_mediatek_of_data mt8516_pwm_data = {
 365         .num_pwms = 5,
 366         .pwm45_fixup = false,
 367         .has_ck_26m_sel = true,
 368         .reg_offset = mtk_pwm_reg_offset_v1,
 369 };
 370
 371 static const struct of_device_id pwm_mediatek_of_match[] = {
 372         { .compatible = "mediatek,mt2712-pwm", .data = &mt2712_pwm_data },
 373         { .compatible = "mediatek,mt6795-pwm", .data = &mt6795_pwm_data },
 374         { .compatible = "mediatek,mt7622-pwm", .data = &mt7622_pwm_data },
 375         { .compatible = "mediatek,mt7623-pwm", .data = &mt7623_pwm_data },
 376         { .compatible = "mediatek,mt7628-pwm", .data = &mt7628_pwm_data },
 377         { .compatible = "mediatek,mt7629-pwm", .data = &mt7629_pwm_data },
 378         { .compatible = "mediatek,mt7981-pwm", .data = &mt7981_pwm_data },
 379         { .compatible = "mediatek,mt7986-pwm", .data = &mt7986_pwm_data },
 380         { .compatible = "mediatek,mt7988-pwm", .data = &mt7988_pwm_data },
 381         { .compatible = "mediatek,mt8183-pwm", .data = &mt8183_pwm_data },
 382         { .compatible = "mediatek,mt8365-pwm", .data = &mt8365_pwm_data },
 383         { .compatible = "mediatek,mt8516-pwm", .data = &mt8516_pwm_data },
 384         { },
 385 };
 386 MODULE_DEVICE_TABLE(of, pwm_mediatek_of_match);
 387
 388 static struct platform_driver pwm_mediatek_driver = {
 389         .driver = {
 390                 .name = "pwm-mediatek",
 391                 .of_match_table = pwm_mediatek_of_match,
 392         },
 393         .probe = pwm_mediatek_probe,
 394 };
 395 module_platform_driver(pwm_mediatek_driver);
 396
 397 MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
 398 MODULE_DESCRIPTION("MediaTek general purpose Pulse Width Modulator driver");
 399 MODULE_LICENSE("GPL v2");