Milo Kim | af66b3c | 2013-12-06 11:18:43 +0900 | [diff] [blame] | 1 | /* |
| 2 | * TI/National Semiconductor LP3943 PWM driver |
| 3 | * |
| 4 | * Copyright 2013 Texas Instruments |
| 5 | * |
| 6 | * Author: Milo Kim <milo.kim@ti.com> |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License as published by |
| 10 | * the Free Software Foundation; version 2. |
| 11 | */ |
| 12 | |
| 13 | #include <linux/err.h> |
| 14 | #include <linux/i2c.h> |
| 15 | #include <linux/mfd/lp3943.h> |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/platform_device.h> |
| 18 | #include <linux/pwm.h> |
| 19 | #include <linux/slab.h> |
| 20 | |
| 21 | #define LP3943_MAX_DUTY 255 |
| 22 | #define LP3943_MIN_PERIOD 6250 |
| 23 | #define LP3943_MAX_PERIOD 1600000 |
| 24 | |
| 25 | struct lp3943_pwm { |
| 26 | struct pwm_chip chip; |
| 27 | struct lp3943 *lp3943; |
| 28 | struct lp3943_platform_data *pdata; |
| 29 | }; |
| 30 | |
| 31 | static inline struct lp3943_pwm *to_lp3943_pwm(struct pwm_chip *_chip) |
| 32 | { |
| 33 | return container_of(_chip, struct lp3943_pwm, chip); |
| 34 | } |
| 35 | |
| 36 | static struct lp3943_pwm_map * |
| 37 | lp3943_pwm_request_map(struct lp3943_pwm *lp3943_pwm, int hwpwm) |
| 38 | { |
| 39 | struct lp3943_platform_data *pdata = lp3943_pwm->pdata; |
| 40 | struct lp3943 *lp3943 = lp3943_pwm->lp3943; |
| 41 | struct lp3943_pwm_map *pwm_map; |
| 42 | int i, offset; |
| 43 | |
| 44 | pwm_map = kzalloc(sizeof(*pwm_map), GFP_KERNEL); |
| 45 | if (!pwm_map) |
| 46 | return ERR_PTR(-ENOMEM); |
| 47 | |
| 48 | pwm_map->output = pdata->pwms[hwpwm]->output; |
| 49 | pwm_map->num_outputs = pdata->pwms[hwpwm]->num_outputs; |
| 50 | |
| 51 | for (i = 0; i < pwm_map->num_outputs; i++) { |
| 52 | offset = pwm_map->output[i]; |
| 53 | |
| 54 | /* Return an error if the pin is already assigned */ |
Christian Engelmayer | 0b7d25c | 2014-01-23 22:32:20 +0100 | [diff] [blame] | 55 | if (test_and_set_bit(offset, &lp3943->pin_used)) { |
| 56 | kfree(pwm_map); |
Milo Kim | af66b3c | 2013-12-06 11:18:43 +0900 | [diff] [blame] | 57 | return ERR_PTR(-EBUSY); |
Christian Engelmayer | 0b7d25c | 2014-01-23 22:32:20 +0100 | [diff] [blame] | 58 | } |
Milo Kim | af66b3c | 2013-12-06 11:18:43 +0900 | [diff] [blame] | 59 | } |
| 60 | |
| 61 | return pwm_map; |
| 62 | } |
| 63 | |
| 64 | static int lp3943_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) |
| 65 | { |
| 66 | struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip); |
| 67 | struct lp3943_pwm_map *pwm_map; |
| 68 | |
| 69 | pwm_map = lp3943_pwm_request_map(lp3943_pwm, pwm->hwpwm); |
| 70 | if (IS_ERR(pwm_map)) |
| 71 | return PTR_ERR(pwm_map); |
| 72 | |
| 73 | return pwm_set_chip_data(pwm, pwm_map); |
| 74 | } |
| 75 | |
| 76 | static void lp3943_pwm_free_map(struct lp3943_pwm *lp3943_pwm, |
| 77 | struct lp3943_pwm_map *pwm_map) |
| 78 | { |
| 79 | struct lp3943 *lp3943 = lp3943_pwm->lp3943; |
| 80 | int i, offset; |
| 81 | |
| 82 | for (i = 0; i < pwm_map->num_outputs; i++) { |
| 83 | offset = pwm_map->output[i]; |
| 84 | clear_bit(offset, &lp3943->pin_used); |
| 85 | } |
| 86 | |
| 87 | kfree(pwm_map); |
| 88 | } |
| 89 | |
| 90 | static void lp3943_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) |
| 91 | { |
| 92 | struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip); |
| 93 | struct lp3943_pwm_map *pwm_map = pwm_get_chip_data(pwm); |
| 94 | |
| 95 | lp3943_pwm_free_map(lp3943_pwm, pwm_map); |
| 96 | } |
| 97 | |
| 98 | static int lp3943_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, |
| 99 | int duty_ns, int period_ns) |
| 100 | { |
| 101 | struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip); |
| 102 | struct lp3943 *lp3943 = lp3943_pwm->lp3943; |
| 103 | u8 val, reg_duty, reg_prescale; |
| 104 | int err; |
| 105 | |
| 106 | /* |
| 107 | * How to configure the LP3943 PWMs |
| 108 | * |
| 109 | * 1) Period = 6250 ~ 1600000 |
| 110 | * 2) Prescale = period / 6250 -1 |
| 111 | * 3) Duty = input duty |
| 112 | * |
| 113 | * Prescale and duty are register values |
| 114 | */ |
| 115 | |
| 116 | if (pwm->hwpwm == 0) { |
| 117 | reg_prescale = LP3943_REG_PRESCALE0; |
| 118 | reg_duty = LP3943_REG_PWM0; |
| 119 | } else { |
| 120 | reg_prescale = LP3943_REG_PRESCALE1; |
| 121 | reg_duty = LP3943_REG_PWM1; |
| 122 | } |
| 123 | |
| 124 | period_ns = clamp(period_ns, LP3943_MIN_PERIOD, LP3943_MAX_PERIOD); |
| 125 | val = (u8)(period_ns / LP3943_MIN_PERIOD - 1); |
| 126 | |
| 127 | err = lp3943_write_byte(lp3943, reg_prescale, val); |
| 128 | if (err) |
| 129 | return err; |
| 130 | |
| 131 | val = (u8)(duty_ns * LP3943_MAX_DUTY / period_ns); |
| 132 | |
| 133 | return lp3943_write_byte(lp3943, reg_duty, val); |
| 134 | } |
| 135 | |
| 136 | static int lp3943_pwm_set_mode(struct lp3943_pwm *lp3943_pwm, |
| 137 | struct lp3943_pwm_map *pwm_map, |
| 138 | u8 val) |
| 139 | { |
| 140 | struct lp3943 *lp3943 = lp3943_pwm->lp3943; |
| 141 | const struct lp3943_reg_cfg *mux = lp3943->mux_cfg; |
| 142 | int i, index, err; |
| 143 | |
| 144 | for (i = 0; i < pwm_map->num_outputs; i++) { |
| 145 | index = pwm_map->output[i]; |
| 146 | err = lp3943_update_bits(lp3943, mux[index].reg, |
| 147 | mux[index].mask, |
| 148 | val << mux[index].shift); |
| 149 | if (err) |
| 150 | return err; |
| 151 | } |
| 152 | |
| 153 | return 0; |
| 154 | } |
| 155 | |
| 156 | static int lp3943_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) |
| 157 | { |
| 158 | struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip); |
| 159 | struct lp3943_pwm_map *pwm_map = pwm_get_chip_data(pwm); |
| 160 | u8 val; |
| 161 | |
| 162 | if (pwm->hwpwm == 0) |
| 163 | val = LP3943_DIM_PWM0; |
| 164 | else |
| 165 | val = LP3943_DIM_PWM1; |
| 166 | |
| 167 | /* |
| 168 | * Each PWM generator is set to control any of outputs of LP3943. |
| 169 | * To enable/disable the PWM, these output pins should be configured. |
| 170 | */ |
| 171 | |
| 172 | return lp3943_pwm_set_mode(lp3943_pwm, pwm_map, val); |
| 173 | } |
| 174 | |
| 175 | static void lp3943_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) |
| 176 | { |
| 177 | struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip); |
| 178 | struct lp3943_pwm_map *pwm_map = pwm_get_chip_data(pwm); |
| 179 | |
| 180 | /* |
| 181 | * LP3943 outputs are open-drain, so the pin should be configured |
| 182 | * when the PWM is disabled. |
| 183 | */ |
| 184 | |
| 185 | lp3943_pwm_set_mode(lp3943_pwm, pwm_map, LP3943_GPIO_OUT_HIGH); |
| 186 | } |
| 187 | |
| 188 | static const struct pwm_ops lp3943_pwm_ops = { |
| 189 | .request = lp3943_pwm_request, |
| 190 | .free = lp3943_pwm_free, |
| 191 | .config = lp3943_pwm_config, |
| 192 | .enable = lp3943_pwm_enable, |
| 193 | .disable = lp3943_pwm_disable, |
| 194 | .owner = THIS_MODULE, |
| 195 | }; |
| 196 | |
| 197 | static int lp3943_pwm_parse_dt(struct device *dev, |
| 198 | struct lp3943_pwm *lp3943_pwm) |
| 199 | { |
| 200 | static const char * const name[] = { "ti,pwm0", "ti,pwm1", }; |
| 201 | struct device_node *node = dev->of_node; |
| 202 | struct lp3943_platform_data *pdata; |
| 203 | struct lp3943_pwm_map *pwm_map; |
| 204 | enum lp3943_pwm_output *output; |
| 205 | int i, err, proplen, count = 0; |
| 206 | u32 num_outputs; |
| 207 | |
| 208 | if (!node) |
| 209 | return -EINVAL; |
| 210 | |
| 211 | pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); |
| 212 | if (!pdata) |
| 213 | return -ENOMEM; |
| 214 | |
| 215 | /* |
| 216 | * Read the output map configuration from the device tree. |
| 217 | * Each of the two PWM generators can drive zero or more outputs. |
| 218 | */ |
| 219 | |
| 220 | for (i = 0; i < LP3943_NUM_PWMS; i++) { |
| 221 | if (!of_get_property(node, name[i], &proplen)) |
| 222 | continue; |
| 223 | |
| 224 | num_outputs = proplen / sizeof(u32); |
| 225 | if (num_outputs == 0) |
| 226 | continue; |
| 227 | |
Kees Cook | a86854d | 2018-06-12 14:07:58 -0700 | [diff] [blame] | 228 | output = devm_kcalloc(dev, num_outputs, sizeof(*output), |
Milo Kim | af66b3c | 2013-12-06 11:18:43 +0900 | [diff] [blame] | 229 | GFP_KERNEL); |
| 230 | if (!output) |
| 231 | return -ENOMEM; |
| 232 | |
| 233 | err = of_property_read_u32_array(node, name[i], output, |
| 234 | num_outputs); |
| 235 | if (err) |
| 236 | return err; |
| 237 | |
| 238 | pwm_map = devm_kzalloc(dev, sizeof(*pwm_map), GFP_KERNEL); |
| 239 | if (!pwm_map) |
| 240 | return -ENOMEM; |
| 241 | |
| 242 | pwm_map->output = output; |
| 243 | pwm_map->num_outputs = num_outputs; |
| 244 | pdata->pwms[i] = pwm_map; |
| 245 | |
| 246 | count++; |
| 247 | } |
| 248 | |
| 249 | if (count == 0) |
| 250 | return -ENODATA; |
| 251 | |
| 252 | lp3943_pwm->pdata = pdata; |
| 253 | return 0; |
| 254 | } |
| 255 | |
| 256 | static int lp3943_pwm_probe(struct platform_device *pdev) |
| 257 | { |
| 258 | struct lp3943 *lp3943 = dev_get_drvdata(pdev->dev.parent); |
| 259 | struct lp3943_pwm *lp3943_pwm; |
| 260 | int ret; |
| 261 | |
| 262 | lp3943_pwm = devm_kzalloc(&pdev->dev, sizeof(*lp3943_pwm), GFP_KERNEL); |
| 263 | if (!lp3943_pwm) |
| 264 | return -ENOMEM; |
| 265 | |
| 266 | lp3943_pwm->pdata = lp3943->pdata; |
| 267 | if (!lp3943_pwm->pdata) { |
| 268 | if (IS_ENABLED(CONFIG_OF)) |
| 269 | ret = lp3943_pwm_parse_dt(&pdev->dev, lp3943_pwm); |
| 270 | else |
| 271 | ret = -ENODEV; |
| 272 | |
| 273 | if (ret) |
| 274 | return ret; |
| 275 | } |
| 276 | |
| 277 | lp3943_pwm->lp3943 = lp3943; |
| 278 | lp3943_pwm->chip.dev = &pdev->dev; |
| 279 | lp3943_pwm->chip.ops = &lp3943_pwm_ops; |
| 280 | lp3943_pwm->chip.npwm = LP3943_NUM_PWMS; |
Milo Kim | af66b3c | 2013-12-06 11:18:43 +0900 | [diff] [blame] | 281 | |
| 282 | platform_set_drvdata(pdev, lp3943_pwm); |
| 283 | |
| 284 | return pwmchip_add(&lp3943_pwm->chip); |
| 285 | } |
| 286 | |
| 287 | static int lp3943_pwm_remove(struct platform_device *pdev) |
| 288 | { |
| 289 | struct lp3943_pwm *lp3943_pwm = platform_get_drvdata(pdev); |
| 290 | |
| 291 | return pwmchip_remove(&lp3943_pwm->chip); |
| 292 | } |
| 293 | |
| 294 | #ifdef CONFIG_OF |
| 295 | static const struct of_device_id lp3943_pwm_of_match[] = { |
| 296 | { .compatible = "ti,lp3943-pwm", }, |
| 297 | { } |
| 298 | }; |
| 299 | MODULE_DEVICE_TABLE(of, lp3943_pwm_of_match); |
| 300 | #endif |
| 301 | |
| 302 | static struct platform_driver lp3943_pwm_driver = { |
| 303 | .probe = lp3943_pwm_probe, |
| 304 | .remove = lp3943_pwm_remove, |
| 305 | .driver = { |
| 306 | .name = "lp3943-pwm", |
Milo Kim | af66b3c | 2013-12-06 11:18:43 +0900 | [diff] [blame] | 307 | .of_match_table = of_match_ptr(lp3943_pwm_of_match), |
| 308 | }, |
| 309 | }; |
| 310 | module_platform_driver(lp3943_pwm_driver); |
| 311 | |
| 312 | MODULE_DESCRIPTION("LP3943 PWM driver"); |
| 313 | MODULE_ALIAS("platform:lp3943-pwm"); |
| 314 | MODULE_AUTHOR("Milo Kim"); |
| 315 | MODULE_LICENSE("GPL"); |