1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * PWM driver for Rockchip SoCs 4 * 5 * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com> 6 * Copyright (C) 2014 ROCKCHIP, Inc. 7 */ 8 9 #include <linux/clk.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/time.h> 17 18 #define PWM_CTRL_TIMER_EN (1 << 0) 19 #define PWM_CTRL_OUTPUT_EN (1 << 3) 20 21 #define PWM_ENABLE (1 << 0) 22 #define PWM_CONTINUOUS (1 << 1) 23 #define PWM_DUTY_POSITIVE (1 << 3) 24 #define PWM_DUTY_NEGATIVE (0 << 3) 25 #define PWM_INACTIVE_NEGATIVE (0 << 4) 26 #define PWM_INACTIVE_POSITIVE (1 << 4) 27 #define PWM_POLARITY_MASK (PWM_DUTY_POSITIVE | PWM_INACTIVE_POSITIVE) 28 #define PWM_OUTPUT_LEFT (0 << 5) 29 #define PWM_LOCK_EN (1 << 6) 30 #define PWM_LP_DISABLE (0 << 8) 31 32 struct rockchip_pwm_chip { 33 struct pwm_chip chip; 34 struct clk *clk; 35 struct clk *pclk; 36 const struct rockchip_pwm_data *data; 37 void __iomem *base; 38 }; 39 40 struct rockchip_pwm_regs { 41 unsigned long duty; 42 unsigned long period; 43 unsigned long cntr; 44 unsigned long ctrl; 45 }; 46 47 struct rockchip_pwm_data { 48 struct rockchip_pwm_regs regs; 49 unsigned int prescaler; 50 bool supports_polarity; 51 bool supports_lock; 52 u32 enable_conf; 53 }; 54 55 static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *c) 56 { 57 return container_of(c, struct rockchip_pwm_chip, chip); 58 } 59 60 static int rockchip_pwm_get_state(struct pwm_chip *chip, 61 struct pwm_device *pwm, 62 struct pwm_state *state) 63 { 64 struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip); 65 u32 enable_conf = pc->data->enable_conf; 66 unsigned long clk_rate; 67 u64 tmp; 68 u32 val; 69 int ret; 70 71 ret = clk_enable(pc->pclk); 72 if (ret) 73 return ret; 74 75 ret = clk_enable(pc->clk); 76 if (ret) 77 return ret; 78 79 clk_rate = clk_get_rate(pc->clk); 80 81 tmp = readl_relaxed(pc->base + pc->data->regs.period); 82 tmp *= pc->data->prescaler * NSEC_PER_SEC; 83 state->period = DIV_ROUND_CLOSEST_ULL(tmp, clk_rate); 84 85 tmp = readl_relaxed(pc->base + pc->data->regs.duty); 86 tmp *= pc->data->prescaler * NSEC_PER_SEC; 87 state->duty_cycle = DIV_ROUND_CLOSEST_ULL(tmp, clk_rate); 88 89 val = readl_relaxed(pc->base + pc->data->regs.ctrl); 90 state->enabled = (val & enable_conf) == enable_conf; 91 92 if (pc->data->supports_polarity && !(val & PWM_DUTY_POSITIVE)) 93 state->polarity = PWM_POLARITY_INVERSED; 94 else 95 state->polarity = PWM_POLARITY_NORMAL; 96 97 clk_disable(pc->clk); 98 clk_disable(pc->pclk); 99 100 return 0; 101 } 102 103 static void rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, 104 const struct pwm_state *state) 105 { 106 struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip); 107 unsigned long period, duty; 108 u64 clk_rate, div; 109 u32 ctrl; 110 111 clk_rate = clk_get_rate(pc->clk); 112 113 /* 114 * Since period and duty cycle registers have a width of 32 115 * bits, every possible input period can be obtained using the 116 * default prescaler value for all practical clock rate values. 117 */ 118 div = clk_rate * state->period; 119 period = DIV_ROUND_CLOSEST_ULL(div, 120 pc->data->prescaler * NSEC_PER_SEC); 121 122 div = clk_rate * state->duty_cycle; 123 duty = DIV_ROUND_CLOSEST_ULL(div, pc->data->prescaler * NSEC_PER_SEC); 124 125 /* 126 * Lock the period and duty of previous configuration, then 127 * change the duty and period, that would not be effective. 128 */ 129 ctrl = readl_relaxed(pc->base + pc->data->regs.ctrl); 130 if (pc->data->supports_lock) { 131 ctrl |= PWM_LOCK_EN; 132 writel_relaxed(ctrl, pc->base + pc->data->regs.ctrl); 133 } 134 135 writel(period, pc->base + pc->data->regs.period); 136 writel(duty, pc->base + pc->data->regs.duty); 137 138 if (pc->data->supports_polarity) { 139 ctrl &= ~PWM_POLARITY_MASK; 140 if (state->polarity == PWM_POLARITY_INVERSED) 141 ctrl |= PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSITIVE; 142 else 143 ctrl |= PWM_DUTY_POSITIVE | PWM_INACTIVE_NEGATIVE; 144 } 145 146 /* 147 * Unlock and set polarity at the same time, 148 * the configuration of duty, period and polarity 149 * would be effective together at next period. 150 */ 151 if (pc->data->supports_lock) 152 ctrl &= ~PWM_LOCK_EN; 153 154 writel(ctrl, pc->base + pc->data->regs.ctrl); 155 } 156 157 static int rockchip_pwm_enable(struct pwm_chip *chip, 158 struct pwm_device *pwm, 159 bool enable) 160 { 161 struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip); 162 u32 enable_conf = pc->data->enable_conf; 163 int ret; 164 u32 val; 165 166 if (enable) { 167 ret = clk_enable(pc->clk); 168 if (ret) 169 return ret; 170 } 171 172 val = readl_relaxed(pc->base + pc->data->regs.ctrl); 173 174 if (enable) 175 val |= enable_conf; 176 else 177 val &= ~enable_conf; 178 179 writel_relaxed(val, pc->base + pc->data->regs.ctrl); 180 181 if (!enable) 182 clk_disable(pc->clk); 183 184 return 0; 185 } 186 187 static int rockchip_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, 188 const struct pwm_state *state) 189 { 190 struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip); 191 struct pwm_state curstate; 192 bool enabled; 193 int ret = 0; 194 195 ret = clk_enable(pc->pclk); 196 if (ret) 197 return ret; 198 199 ret = clk_enable(pc->clk); 200 if (ret) 201 return ret; 202 203 pwm_get_state(pwm, &curstate); 204 enabled = curstate.enabled; 205 206 if (state->polarity != curstate.polarity && enabled && 207 !pc->data->supports_lock) { 208 ret = rockchip_pwm_enable(chip, pwm, false); 209 if (ret) 210 goto out; 211 enabled = false; 212 } 213 214 rockchip_pwm_config(chip, pwm, state); 215 if (state->enabled != enabled) { 216 ret = rockchip_pwm_enable(chip, pwm, state->enabled); 217 if (ret) 218 goto out; 219 } 220 221 out: 222 clk_disable(pc->clk); 223 clk_disable(pc->pclk); 224 225 return ret; 226 } 227 228 static const struct pwm_ops rockchip_pwm_ops = { 229 .get_state = rockchip_pwm_get_state, 230 .apply = rockchip_pwm_apply, 231 .owner = THIS_MODULE, 232 }; 233 234 static const struct rockchip_pwm_data pwm_data_v1 = { 235 .regs = { 236 .duty = 0x04, 237 .period = 0x08, 238 .cntr = 0x00, 239 .ctrl = 0x0c, 240 }, 241 .prescaler = 2, 242 .supports_polarity = false, 243 .supports_lock = false, 244 .enable_conf = PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN, 245 }; 246 247 static const struct rockchip_pwm_data pwm_data_v2 = { 248 .regs = { 249 .duty = 0x08, 250 .period = 0x04, 251 .cntr = 0x00, 252 .ctrl = 0x0c, 253 }, 254 .prescaler = 1, 255 .supports_polarity = true, 256 .supports_lock = false, 257 .enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE | 258 PWM_CONTINUOUS, 259 }; 260 261 static const struct rockchip_pwm_data pwm_data_vop = { 262 .regs = { 263 .duty = 0x08, 264 .period = 0x04, 265 .cntr = 0x0c, 266 .ctrl = 0x00, 267 }, 268 .prescaler = 1, 269 .supports_polarity = true, 270 .supports_lock = false, 271 .enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE | 272 PWM_CONTINUOUS, 273 }; 274 275 static const struct rockchip_pwm_data pwm_data_v3 = { 276 .regs = { 277 .duty = 0x08, 278 .period = 0x04, 279 .cntr = 0x00, 280 .ctrl = 0x0c, 281 }, 282 .prescaler = 1, 283 .supports_polarity = true, 284 .supports_lock = true, 285 .enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE | 286 PWM_CONTINUOUS, 287 }; 288 289 static const struct of_device_id rockchip_pwm_dt_ids[] = { 290 { .compatible = "rockchip,rk2928-pwm", .data = &pwm_data_v1}, 291 { .compatible = "rockchip,rk3288-pwm", .data = &pwm_data_v2}, 292 { .compatible = "rockchip,vop-pwm", .data = &pwm_data_vop}, 293 { .compatible = "rockchip,rk3328-pwm", .data = &pwm_data_v3}, 294 { /* sentinel */ } 295 }; 296 MODULE_DEVICE_TABLE(of, rockchip_pwm_dt_ids); 297 298 static int rockchip_pwm_probe(struct platform_device *pdev) 299 { 300 const struct of_device_id *id; 301 struct rockchip_pwm_chip *pc; 302 u32 enable_conf, ctrl; 303 bool enabled; 304 int ret, count; 305 306 id = of_match_device(rockchip_pwm_dt_ids, &pdev->dev); 307 if (!id) 308 return -EINVAL; 309 310 pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); 311 if (!pc) 312 return -ENOMEM; 313 314 pc->base = devm_platform_ioremap_resource(pdev, 0); 315 if (IS_ERR(pc->base)) 316 return PTR_ERR(pc->base); 317 318 pc->clk = devm_clk_get(&pdev->dev, "pwm"); 319 if (IS_ERR(pc->clk)) { 320 pc->clk = devm_clk_get(&pdev->dev, NULL); 321 if (IS_ERR(pc->clk)) 322 return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk), 323 "Can't get PWM clk\n"); 324 } 325 326 count = of_count_phandle_with_args(pdev->dev.of_node, 327 "clocks", "#clock-cells"); 328 if (count == 2) 329 pc->pclk = devm_clk_get(&pdev->dev, "pclk"); 330 else 331 pc->pclk = pc->clk; 332 333 if (IS_ERR(pc->pclk)) 334 return dev_err_probe(&pdev->dev, PTR_ERR(pc->pclk), "Can't get APB clk\n"); 335 336 ret = clk_prepare_enable(pc->clk); 337 if (ret) 338 return dev_err_probe(&pdev->dev, ret, "Can't prepare enable PWM clk\n"); 339 340 ret = clk_prepare_enable(pc->pclk); 341 if (ret) { 342 dev_err_probe(&pdev->dev, ret, "Can't prepare enable APB clk\n"); 343 goto err_clk; 344 } 345 346 platform_set_drvdata(pdev, pc); 347 348 pc->data = id->data; 349 pc->chip.dev = &pdev->dev; 350 pc->chip.ops = &rockchip_pwm_ops; 351 pc->chip.npwm = 1; 352 353 enable_conf = pc->data->enable_conf; 354 ctrl = readl_relaxed(pc->base + pc->data->regs.ctrl); 355 enabled = (ctrl & enable_conf) == enable_conf; 356 357 ret = pwmchip_add(&pc->chip); 358 if (ret < 0) { 359 dev_err_probe(&pdev->dev, ret, "pwmchip_add() failed\n"); 360 goto err_pclk; 361 } 362 363 /* Keep the PWM clk enabled if the PWM appears to be up and running. */ 364 if (!enabled) 365 clk_disable(pc->clk); 366 367 clk_disable(pc->pclk); 368 369 return 0; 370 371 err_pclk: 372 clk_disable_unprepare(pc->pclk); 373 err_clk: 374 clk_disable_unprepare(pc->clk); 375 376 return ret; 377 } 378 379 static void rockchip_pwm_remove(struct platform_device *pdev) 380 { 381 struct rockchip_pwm_chip *pc = platform_get_drvdata(pdev); 382 383 pwmchip_remove(&pc->chip); 384 385 clk_unprepare(pc->pclk); 386 clk_unprepare(pc->clk); 387 } 388 389 static struct platform_driver rockchip_pwm_driver = { 390 .driver = { 391 .name = "rockchip-pwm", 392 .of_match_table = rockchip_pwm_dt_ids, 393 }, 394 .probe = rockchip_pwm_probe, 395 .remove_new = rockchip_pwm_remove, 396 }; 397 module_platform_driver(rockchip_pwm_driver); 398 399 MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>"); 400 MODULE_DESCRIPTION("Rockchip SoC PWM driver"); 401 MODULE_LICENSE("GPL v2"); 402