drivers/pwm/pwm-hibvt.c

   1 /*
   2  * PWM Controller Driver for HiSilicon BVT SoCs
   3  *
   4  * Copyright (c) 2016 HiSilicon Technologies Co., Ltd.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <linux/bitops.h>
  21 #include <linux/clk.h>
  22 #include <linux/delay.h>
  23 #include <linux/io.h>
  24 #include <linux/module.h>
  25 #include <linux/of_device.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/pwm.h>
  28 #include <linux/reset.h>
  29
  30 #define PWM_CFG0_ADDR(x)    (((x) * 0x20) + 0x0)
  31 #define PWM_CFG1_ADDR(x)    (((x) * 0x20) + 0x4)
  32 #define PWM_CFG2_ADDR(x)    (((x) * 0x20) + 0x8)
  33 #define PWM_CTRL_ADDR(x)    (((x) * 0x20) + 0xC)
  34
  35 #define PWM_ENABLE_SHIFT    0
  36 #define PWM_ENABLE_MASK     BIT(0)
  37
  38 #define PWM_POLARITY_SHIFT  1
  39 #define PWM_POLARITY_MASK   BIT(1)
  40
  41 #define PWM_KEEP_SHIFT      2
  42 #define PWM_KEEP_MASK       BIT(2)
  43
  44 #define PWM_PERIOD_MASK     GENMASK(31, 0)
  45 #define PWM_DUTY_MASK       GENMASK(31, 0)
  46
  47 struct hibvt_pwm_chip {
  48         struct pwm_chip chip;
  49         struct clk *clk;
  50         void __iomem *base;
  51         struct reset_control *rstc;
  52         const struct hibvt_pwm_soc *soc;
  53 };
  54
  55 struct hibvt_pwm_soc {
  56         u32 num_pwms;
  57         bool quirk_force_enable;
  58 };
  59
  60 static const struct hibvt_pwm_soc hi3516cv300_soc_info = {
  61         .num_pwms = 4,
  62 };
  63
  64 static const struct hibvt_pwm_soc hi3519v100_soc_info = {
  65         .num_pwms = 8,
  66 };
  67
  68 static const struct hibvt_pwm_soc hi3559v100_shub_soc_info = {
  69         .num_pwms = 8,
  70         .quirk_force_enable = true,
  71 };
  72
  73 static const struct hibvt_pwm_soc hi3559v100_soc_info = {
  74         .num_pwms = 2,
  75         .quirk_force_enable = true,
  76 };
  77
  78 static inline struct hibvt_pwm_chip *to_hibvt_pwm_chip(struct pwm_chip *chip)
  79 {
  80         return container_of(chip, struct hibvt_pwm_chip, chip);
  81 }
  82
  83 static void hibvt_pwm_set_bits(void __iomem *base, u32 offset,
  84                                         u32 mask, u32 data)
  85 {
  86         void __iomem *address = base + offset;
  87         u32 value;
  88
  89         value = readl(address);
  90         value &= ~mask;
  91         value |= (data & mask);
  92         writel(value, address);
  93 }
  94
  95 static void hibvt_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
  96 {
  97         struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
  98
  99         hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CTRL_ADDR(pwm->hwpwm),
 100                         PWM_ENABLE_MASK, 0x1);
 101 }
 102
 103 static void hibvt_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 104 {
 105         struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
 106
 107         hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CTRL_ADDR(pwm->hwpwm),
 108                         PWM_ENABLE_MASK, 0x0);
 109 }
 110
 111 static void hibvt_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 112                                         int duty_cycle_ns, int period_ns)
 113 {
 114         struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
 115         u32 freq, period, duty;
 116
 117         freq = div_u64(clk_get_rate(hi_pwm_chip->clk), 1000000);
 118
 119         period = div_u64(freq * period_ns, 1000);
 120         duty = div_u64(period * duty_cycle_ns, period_ns);
 121
 122         hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CFG0_ADDR(pwm->hwpwm),
 123                         PWM_PERIOD_MASK, period);
 124
 125         hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CFG1_ADDR(pwm->hwpwm),
 126                         PWM_DUTY_MASK, duty);
 127 }
 128
 129 static void hibvt_pwm_set_polarity(struct pwm_chip *chip,
 130                                         struct pwm_device *pwm,
 131                                         enum pwm_polarity polarity)
 132 {
 133         struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
 134
 135         if (polarity == PWM_POLARITY_INVERSED)
 136                 hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CTRL_ADDR(pwm->hwpwm),
 137                                 PWM_POLARITY_MASK, (0x1 << PWM_POLARITY_SHIFT));
 138         else
 139                 hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CTRL_ADDR(pwm->hwpwm),
 140                                 PWM_POLARITY_MASK, (0x0 << PWM_POLARITY_SHIFT));
 141 }
 142
 143 static void hibvt_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
 144                                 struct pwm_state *state)
 145 {
 146         struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
 147         void __iomem *base;
 148         u32 freq, value;
 149
 150         freq = div_u64(clk_get_rate(hi_pwm_chip->clk), 1000000);
 151         base = hi_pwm_chip->base;
 152
 153         value = readl(base + PWM_CFG0_ADDR(pwm->hwpwm));
 154         state->period = div_u64(value * 1000, freq);
 155
 156         value = readl(base + PWM_CFG1_ADDR(pwm->hwpwm));
 157         state->duty_cycle = div_u64(value * 1000, freq);
 158
 159         value = readl(base + PWM_CTRL_ADDR(pwm->hwpwm));
 160         state->enabled = (PWM_ENABLE_MASK & value);
 161 }
 162
 163 static int hibvt_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 164                                 struct pwm_state *state)
 165 {
 166         struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
 167
 168         if (state->polarity != pwm->state.polarity)
 169                 hibvt_pwm_set_polarity(chip, pwm, state->polarity);
 170
 171         if (state->period != pwm->state.period ||
 172             state->duty_cycle != pwm->state.duty_cycle) {
 173                 hibvt_pwm_config(chip, pwm, state->duty_cycle, state->period);
 174
 175                 /*
 176                  * Some implementations require the PWM to be enabled twice
 177                  * each time the duty cycle is refreshed.
 178                  */
 179                 if (hi_pwm_chip->soc->quirk_force_enable && state->enabled)
 180                         hibvt_pwm_enable(chip, pwm);
 181         }
 182
 183         if (state->enabled != pwm->state.enabled) {
 184                 if (state->enabled)
 185                         hibvt_pwm_enable(chip, pwm);
 186                 else
 187                         hibvt_pwm_disable(chip, pwm);
 188         }
 189
 190         return 0;
 191 }
 192
 193 static const struct pwm_ops hibvt_pwm_ops = {
 194         .get_state = hibvt_pwm_get_state,
 195         .apply = hibvt_pwm_apply,
 196
 197         .owner = THIS_MODULE,
 198 };
 199
 200 static int hibvt_pwm_probe(struct platform_device *pdev)
 201 {
 202         const struct hibvt_pwm_soc *soc =
 203                                 of_device_get_match_data(&pdev->dev);
 204         struct hibvt_pwm_chip *pwm_chip;
 205         struct resource *res;
 206         int ret;
 207         int i;
 208
 209         pwm_chip = devm_kzalloc(&pdev->dev, sizeof(*pwm_chip), GFP_KERNEL);
 210         if (pwm_chip == NULL)
 211                 return -ENOMEM;
 212
 213         pwm_chip->clk = devm_clk_get(&pdev->dev, NULL);
 214         if (IS_ERR(pwm_chip->clk)) {
 215                 dev_err(&pdev->dev, "getting clock failed with %ld\n",
 216                                 PTR_ERR(pwm_chip->clk));
 217                 return PTR_ERR(pwm_chip->clk);
 218         }
 219
 220         pwm_chip->chip.ops = &hibvt_pwm_ops;
 221         pwm_chip->chip.dev = &pdev->dev;
 222         pwm_chip->chip.base = -1;
 223         pwm_chip->chip.npwm = soc->num_pwms;
 224         pwm_chip->chip.of_xlate = of_pwm_xlate_with_flags;
 225         pwm_chip->chip.of_pwm_n_cells = 3;
 226         pwm_chip->soc = soc;
 227
 228         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 229         pwm_chip->base = devm_ioremap_resource(&pdev->dev, res);
 230         if (IS_ERR(pwm_chip->base))
 231                 return PTR_ERR(pwm_chip->base);
 232
 233         ret = clk_prepare_enable(pwm_chip->clk);
 234         if (ret < 0)
 235                 return ret;
 236
 237         pwm_chip->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
 238         if (IS_ERR(pwm_chip->rstc)) {
 239                 clk_disable_unprepare(pwm_chip->clk);
 240                 return PTR_ERR(pwm_chip->rstc);
 241         }
 242
 243         reset_control_assert(pwm_chip->rstc);
 244         msleep(30);
 245         reset_control_deassert(pwm_chip->rstc);
 246
 247         ret = pwmchip_add(&pwm_chip->chip);
 248         if (ret < 0) {
 249                 clk_disable_unprepare(pwm_chip->clk);
 250                 return ret;
 251         }
 252
 253         for (i = 0; i < pwm_chip->chip.npwm; i++) {
 254                 hibvt_pwm_set_bits(pwm_chip->base, PWM_CTRL_ADDR(i),
 255                                 PWM_KEEP_MASK, (0x1 << PWM_KEEP_SHIFT));
 256         }
 257
 258         platform_set_drvdata(pdev, pwm_chip);
 259
 260         return 0;
 261 }
 262
 263 static int hibvt_pwm_remove(struct platform_device *pdev)
 264 {
 265         struct hibvt_pwm_chip *pwm_chip;
 266
 267         pwm_chip = platform_get_drvdata(pdev);
 268
 269         reset_control_assert(pwm_chip->rstc);
 270         msleep(30);
 271         reset_control_deassert(pwm_chip->rstc);
 272
 273         clk_disable_unprepare(pwm_chip->clk);
 274
 275         return pwmchip_remove(&pwm_chip->chip);
 276 }
 277
 278 static const struct of_device_id hibvt_pwm_of_match[] = {
 279         { .compatible = "hisilicon,hi3516cv300-pwm",
 280           .data = &hi3516cv300_soc_info },
 281         { .compatible = "hisilicon,hi3519v100-pwm",
 282           .data = &hi3519v100_soc_info },
 283         { .compatible = "hisilicon,hi3559v100-shub-pwm",
 284           .data = &hi3559v100_shub_soc_info },
 285         { .compatible = "hisilicon,hi3559v100-pwm",
 286           .data = &hi3559v100_soc_info },
 287         {  }
 288 };
 289 MODULE_DEVICE_TABLE(of, hibvt_pwm_of_match);
 290
 291 static struct platform_driver hibvt_pwm_driver = {
 292         .driver = {
 293                 .name = "hibvt-pwm",
 294                 .of_match_table = hibvt_pwm_of_match,
 295         },
 296         .probe = hibvt_pwm_probe,
 297         .remove = hibvt_pwm_remove,
 298 };
 299 module_platform_driver(hibvt_pwm_driver);
 300
 301 MODULE_AUTHOR("Jian Yuan");
 302 MODULE_DESCRIPTION("HiSilicon BVT SoCs PWM driver");
 303 MODULE_LICENSE("GPL");