| 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 void pwm_mediatek_writel(struct pwm_mediatek_chip *chip, |
| 111 | unsigned int num, unsigned int offset, |
| 112 | u32 value) |
| 113 | { |
| 114 | writel(value, chip->regs + pwm_mediatek_reg_offset[num] + offset); |
| 115 | } |
| 116 | |
| 117 | static int pwm_mediatek_config(struct pwm_chip *chip, struct pwm_device *pwm, |
| 118 | int duty_ns, int period_ns) |
| 119 | { |
| 120 | struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip); |
| 121 | u32 clkdiv = 0, cnt_period, cnt_duty, reg_width = PWMDWIDTH, |
| 122 | reg_thres = PWMTHRES; |
| 123 | u64 resolution; |
| 124 | int ret; |
| 125 | |
| 126 | ret = pwm_mediatek_clk_enable(chip, pwm); |
| 127 | |
| 128 | if (ret < 0) |
| 129 | return ret; |
| 130 | |
| 131 | /* Make sure we use the bus clock and not the 26MHz clock */ |
| 132 | if (pc->soc->has_ck_26m_sel) |
| 133 | writel(0, pc->regs + PWM_CK_26M_SEL); |
| 134 | |
| 135 | /* Using resolution in picosecond gets accuracy higher */ |
| 136 | resolution = (u64)NSEC_PER_SEC * 1000; |
| 137 | do_div(resolution, clk_get_rate(pc->clk_pwms[pwm->hwpwm])); |
| 138 | |
| 139 | cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000, resolution); |
| 140 | while (cnt_period > 8191) { |
| 141 | resolution *= 2; |
| 142 | clkdiv++; |
| 143 | cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000, |
| 144 | resolution); |
| 145 | } |
| 146 | |
| 147 | if (clkdiv > PWM_CLK_DIV_MAX) { |
| 148 | pwm_mediatek_clk_disable(chip, pwm); |
| 149 | dev_err(chip->dev, "period of %d ns not supported\n", period_ns); |
| 150 | return -EINVAL; |
| 151 | } |
| 152 | |
| 153 | if (pc->soc->pwm45_fixup && pwm->hwpwm > 2) { |
| 154 | /* |
| 155 | * PWM[4,5] has distinct offset for PWMDWIDTH and PWMTHRES |
| 156 | * from the other PWMs on MT7623. |
| 157 | */ |
| 158 | reg_width = PWM45DWIDTH_FIXUP; |
| 159 | reg_thres = PWM45THRES_FIXUP; |
| 160 | } |
| 161 | |
| 162 | cnt_duty = DIV_ROUND_CLOSEST_ULL((u64)duty_ns * 1000, resolution); |
| 163 | pwm_mediatek_writel(pc, pwm->hwpwm, PWMCON, BIT(15) | clkdiv); |
| 164 | pwm_mediatek_writel(pc, pwm->hwpwm, reg_width, cnt_period); |
| 165 | pwm_mediatek_writel(pc, pwm->hwpwm, reg_thres, cnt_duty); |
| 166 | |
| 167 | pwm_mediatek_clk_disable(chip, pwm); |
| 168 | |
| 169 | return 0; |
| 170 | } |
| 171 | |
| 172 | static int pwm_mediatek_enable(struct pwm_chip *chip, struct pwm_device *pwm) |
| 173 | { |
| 174 | struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip); |
| 175 | u32 value; |
| 176 | int ret; |
| 177 | |
| 178 | ret = pwm_mediatek_clk_enable(chip, pwm); |
| 179 | if (ret < 0) |
| 180 | return ret; |
| 181 | |
| 182 | value = readl(pc->regs); |
| 183 | value |= BIT(pwm->hwpwm); |
| 184 | writel(value, pc->regs); |
| 185 | |
| 186 | return 0; |
| 187 | } |
| 188 | |
| 189 | static void pwm_mediatek_disable(struct pwm_chip *chip, struct pwm_device *pwm) |
| 190 | { |
| 191 | struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip); |
| 192 | u32 value; |
| 193 | |
| 194 | value = readl(pc->regs); |
| 195 | value &= ~BIT(pwm->hwpwm); |
| 196 | writel(value, pc->regs); |
| 197 | |
| 198 | pwm_mediatek_clk_disable(chip, pwm); |
| 199 | } |
| 200 | |
| 201 | static int pwm_mediatek_apply(struct pwm_chip *chip, struct pwm_device *pwm, |
| 202 | const struct pwm_state *state) |
| 203 | { |
| 204 | int err; |
| 205 | |
| 206 | if (state->polarity != PWM_POLARITY_NORMAL) |
| 207 | return -EINVAL; |
| 208 | |
| 209 | if (!state->enabled) { |
| 210 | if (pwm->state.enabled) |
| 211 | pwm_mediatek_disable(chip, pwm); |
| 212 | |
| 213 | return 0; |
| 214 | } |
| 215 | |
| 216 | err = pwm_mediatek_config(pwm->chip, pwm, state->duty_cycle, state->period); |
| 217 | if (err) |
| 218 | return err; |
| 219 | |
| 220 | if (!pwm->state.enabled) |
| 221 | err = pwm_mediatek_enable(chip, pwm); |
| 222 | |
| 223 | return err; |
| 224 | } |
| 225 | |
| 226 | static const struct pwm_ops pwm_mediatek_ops = { |
| 227 | .apply = pwm_mediatek_apply, |
| 228 | .owner = THIS_MODULE, |
| 229 | }; |
| 230 | |
| 231 | static int pwm_mediatek_probe(struct platform_device *pdev) |
| 232 | { |
| 233 | struct pwm_mediatek_chip *pc; |
| 234 | unsigned int i; |
| 235 | int ret; |
| 236 | |
| 237 | pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); |
| 238 | if (!pc) |
| 239 | return -ENOMEM; |
| 240 | |
| 241 | pc->soc = of_device_get_match_data(&pdev->dev); |
| 242 | |
| 243 | pc->regs = devm_platform_ioremap_resource(pdev, 0); |
| 244 | if (IS_ERR(pc->regs)) |
| 245 | return PTR_ERR(pc->regs); |
| 246 | |
| 247 | pc->clk_pwms = devm_kmalloc_array(&pdev->dev, pc->soc->num_pwms, |
| 248 | sizeof(*pc->clk_pwms), GFP_KERNEL); |
| 249 | if (!pc->clk_pwms) |
| 250 | return -ENOMEM; |
| 251 | |
| 252 | pc->clk_top = devm_clk_get(&pdev->dev, "top"); |
| 253 | if (IS_ERR(pc->clk_top)) |
| 254 | return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk_top), |
| 255 | "Failed to get top clock\n"); |
| 256 | |
| 257 | pc->clk_main = devm_clk_get(&pdev->dev, "main"); |
| 258 | if (IS_ERR(pc->clk_main)) |
| 259 | return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk_main), |
| 260 | "Failed to get main clock\n"); |
| 261 | |
| 262 | for (i = 0; i < pc->soc->num_pwms; i++) { |
| 263 | char name[8]; |
| 264 | |
| 265 | snprintf(name, sizeof(name), "pwm%d", i + 1); |
| 266 | |
| 267 | pc->clk_pwms[i] = devm_clk_get(&pdev->dev, name); |
| 268 | if (IS_ERR(pc->clk_pwms[i])) |
| 269 | return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk_pwms[i]), |
| 270 | "Failed to get %s clock\n", name); |
| 271 | } |
| 272 | |
| 273 | pc->chip.dev = &pdev->dev; |
| 274 | pc->chip.ops = &pwm_mediatek_ops; |
| 275 | pc->chip.npwm = pc->soc->num_pwms; |
| 276 | |
| 277 | ret = devm_pwmchip_add(&pdev->dev, &pc->chip); |
| 278 | if (ret < 0) |
| 279 | return dev_err_probe(&pdev->dev, ret, "pwmchip_add() failed\n"); |
| 280 | |
| 281 | return 0; |
| 282 | } |
| 283 | |
| 284 | static const struct pwm_mediatek_of_data mt2712_pwm_data = { |
| 285 | .num_pwms = 8, |
| 286 | .pwm45_fixup = false, |
| 287 | .has_ck_26m_sel = false, |
| 288 | }; |
| 289 | |
| 290 | static const struct pwm_mediatek_of_data mt6795_pwm_data = { |
| 291 | .num_pwms = 7, |
| 292 | .pwm45_fixup = false, |
| 293 | .has_ck_26m_sel = false, |
| 294 | }; |
| 295 | |
| 296 | static const struct pwm_mediatek_of_data mt7622_pwm_data = { |
| 297 | .num_pwms = 6, |
| 298 | .pwm45_fixup = false, |
| 299 | .has_ck_26m_sel = true, |
| 300 | }; |
| 301 | |
| 302 | static const struct pwm_mediatek_of_data mt7623_pwm_data = { |
| 303 | .num_pwms = 5, |
| 304 | .pwm45_fixup = true, |
| 305 | .has_ck_26m_sel = false, |
| 306 | }; |
| 307 | |
| 308 | static const struct pwm_mediatek_of_data mt7628_pwm_data = { |
| 309 | .num_pwms = 4, |
| 310 | .pwm45_fixup = true, |
| 311 | .has_ck_26m_sel = false, |
| 312 | }; |
| 313 | |
| 314 | static const struct pwm_mediatek_of_data mt7629_pwm_data = { |
| 315 | .num_pwms = 1, |
| 316 | .pwm45_fixup = false, |
| 317 | .has_ck_26m_sel = false, |
| 318 | }; |
| 319 | |
| 320 | static const struct pwm_mediatek_of_data mt8183_pwm_data = { |
| 321 | .num_pwms = 4, |
| 322 | .pwm45_fixup = false, |
| 323 | .has_ck_26m_sel = true, |
| 324 | }; |
| 325 | |
| 326 | static const struct pwm_mediatek_of_data mt8365_pwm_data = { |
| 327 | .num_pwms = 3, |
| 328 | .pwm45_fixup = false, |
| 329 | .has_ck_26m_sel = true, |
| 330 | }; |
| 331 | |
| 332 | static const struct pwm_mediatek_of_data mt7986_pwm_data = { |
| 333 | .num_pwms = 2, |
| 334 | .pwm45_fixup = false, |
| 335 | .has_ck_26m_sel = true, |
| 336 | }; |
| 337 | |
| 338 | static const struct pwm_mediatek_of_data mt8516_pwm_data = { |
| 339 | .num_pwms = 5, |
| 340 | .pwm45_fixup = false, |
| 341 | .has_ck_26m_sel = true, |
| 342 | }; |
| 343 | |
| 344 | static const struct of_device_id pwm_mediatek_of_match[] = { |
| 345 | { .compatible = "mediatek,mt2712-pwm", .data = &mt2712_pwm_data }, |
| 346 | { .compatible = "mediatek,mt6795-pwm", .data = &mt6795_pwm_data }, |
| 347 | { .compatible = "mediatek,mt7622-pwm", .data = &mt7622_pwm_data }, |
| 348 | { .compatible = "mediatek,mt7623-pwm", .data = &mt7623_pwm_data }, |
| 349 | { .compatible = "mediatek,mt7628-pwm", .data = &mt7628_pwm_data }, |
| 350 | { .compatible = "mediatek,mt7629-pwm", .data = &mt7629_pwm_data }, |
| 351 | { .compatible = "mediatek,mt7986-pwm", .data = &mt7986_pwm_data }, |
| 352 | { .compatible = "mediatek,mt8183-pwm", .data = &mt8183_pwm_data }, |
| 353 | { .compatible = "mediatek,mt8365-pwm", .data = &mt8365_pwm_data }, |
| 354 | { .compatible = "mediatek,mt8516-pwm", .data = &mt8516_pwm_data }, |
| 355 | { }, |
| 356 | }; |
| 357 | MODULE_DEVICE_TABLE(of, pwm_mediatek_of_match); |
| 358 | |
| 359 | static struct platform_driver pwm_mediatek_driver = { |
| 360 | .driver = { |
| 361 | .name = "pwm-mediatek", |
| 362 | .of_match_table = pwm_mediatek_of_match, |
| 363 | }, |
| 364 | .probe = pwm_mediatek_probe, |
| 365 | }; |
| 366 | module_platform_driver(pwm_mediatek_driver); |
| 367 | |
| 368 | MODULE_AUTHOR("John Crispin <blogic@openwrt.org>"); |
| 369 | MODULE_LICENSE("GPL v2"); |