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 };
  53
  54 struct hibvt_pwm_soc {
  55         u32 num_pwms;
  56 };
  57
  58 static const struct hibvt_pwm_soc pwm_soc[2] = {
  59         { .num_pwms = 4 },
  60         { .num_pwms = 8 },
  61 };
  62
  63 static inline struct hibvt_pwm_chip *to_hibvt_pwm_chip(struct pwm_chip *chip)
  64 {
  65         return container_of(chip, struct hibvt_pwm_chip, chip);
  66 }
  67
  68 static void hibvt_pwm_set_bits(void __iomem *base, u32 offset,
  69                                         u32 mask, u32 data)
  70 {
  71         void __iomem *address = base + offset;
  72         u32 value;
  73
  74         value = readl(address);
  75         value &= ~mask;
  76         value |= (data & mask);
  77         writel(value, address);
  78 }
  79
  80 static void hibvt_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
  81 {
  82         struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
  83
  84         hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CTRL_ADDR(pwm->hwpwm),
  85                         PWM_ENABLE_MASK, 0x1);
  86 }
  87
  88 static void hibvt_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
  89 {
  90         struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
  91
  92         hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CTRL_ADDR(pwm->hwpwm),
  93                         PWM_ENABLE_MASK, 0x0);
  94 }
  95
  96 static void hibvt_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
  97                                         int duty_cycle_ns, int period_ns)
  98 {
  99         struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
 100         u32 freq, period, duty;
 101
 102         freq = div_u64(clk_get_rate(hi_pwm_chip->clk), 1000000);
 103
 104         period = div_u64(freq * period_ns, 1000);
 105         duty = div_u64(period * duty_cycle_ns, period_ns);
 106
 107         hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CFG0_ADDR(pwm->hwpwm),
 108                         PWM_PERIOD_MASK, period);
 109
 110         hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CFG1_ADDR(pwm->hwpwm),
 111                         PWM_DUTY_MASK, duty);
 112 }
 113
 114 static void hibvt_pwm_set_polarity(struct pwm_chip *chip,
 115                                         struct pwm_device *pwm,
 116                                         enum pwm_polarity polarity)
 117 {
 118         struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
 119
 120         if (polarity == PWM_POLARITY_INVERSED)
 121                 hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CTRL_ADDR(pwm->hwpwm),
 122                                 PWM_POLARITY_MASK, (0x1 << PWM_POLARITY_SHIFT));
 123         else
 124                 hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CTRL_ADDR(pwm->hwpwm),
 125                                 PWM_POLARITY_MASK, (0x0 << PWM_POLARITY_SHIFT));
 126 }
 127
 128 static void hibvt_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
 129                                 struct pwm_state *state)
 130 {
 131         struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
 132         void __iomem *base;
 133         u32 freq, value;
 134
 135         freq = div_u64(clk_get_rate(hi_pwm_chip->clk), 1000000);
 136         base = hi_pwm_chip->base;
 137
 138         value = readl(base + PWM_CFG0_ADDR(pwm->hwpwm));
 139         state->period = div_u64(value * 1000, freq);
 140
 141         value = readl(base + PWM_CFG1_ADDR(pwm->hwpwm));
 142         state->duty_cycle = div_u64(value * 1000, freq);
 143
 144         value = readl(base + PWM_CTRL_ADDR(pwm->hwpwm));
 145         state->enabled = (PWM_ENABLE_MASK & value);
 146 }
 147
 148 static int hibvt_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 149                                 struct pwm_state *state)
 150 {
 151         if (state->polarity != pwm->state.polarity)
 152                 hibvt_pwm_set_polarity(chip, pwm, state->polarity);
 153
 154         if (state->period != pwm->state.period ||
 155                 state->duty_cycle != pwm->state.duty_cycle)
 156                 hibvt_pwm_config(chip, pwm, state->duty_cycle, state->period);
 157
 158         if (state->enabled != pwm->state.enabled) {
 159                 if (state->enabled)
 160                         hibvt_pwm_enable(chip, pwm);
 161                 else
 162                         hibvt_pwm_disable(chip, pwm);
 163         }
 164
 165         return 0;
 166 }
 167
 168 static struct pwm_ops hibvt_pwm_ops = {
 169         .get_state = hibvt_pwm_get_state,
 170         .apply = hibvt_pwm_apply,
 171
 172         .owner = THIS_MODULE,
 173 };
 174
 175 static int hibvt_pwm_probe(struct platform_device *pdev)
 176 {
 177         const struct hibvt_pwm_soc *soc =
 178                                 of_device_get_match_data(&pdev->dev);
 179         struct hibvt_pwm_chip *pwm_chip;
 180         struct resource *res;
 181         int ret;
 182         int i;
 183
 184         pwm_chip = devm_kzalloc(&pdev->dev, sizeof(*pwm_chip), GFP_KERNEL);
 185         if (pwm_chip == NULL)
 186                 return -ENOMEM;
 187
 188         pwm_chip->clk = devm_clk_get(&pdev->dev, NULL);
 189         if (IS_ERR(pwm_chip->clk)) {
 190                 dev_err(&pdev->dev, "getting clock failed with %ld\n",
 191                                 PTR_ERR(pwm_chip->clk));
 192                 return PTR_ERR(pwm_chip->clk);
 193         }
 194
 195         pwm_chip->chip.ops = &hibvt_pwm_ops;
 196         pwm_chip->chip.dev = &pdev->dev;
 197         pwm_chip->chip.base = -1;
 198         pwm_chip->chip.npwm = soc->num_pwms;
 199         pwm_chip->chip.of_xlate = of_pwm_xlate_with_flags;
 200         pwm_chip->chip.of_pwm_n_cells = 3;
 201
 202         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 203         pwm_chip->base = devm_ioremap_resource(&pdev->dev, res);
 204         if (IS_ERR(pwm_chip->base))
 205                 return PTR_ERR(pwm_chip->base);
 206
 207         ret = clk_prepare_enable(pwm_chip->clk);
 208         if (ret < 0)
 209                 return ret;
 210
 211         pwm_chip->rstc = devm_reset_control_get(&pdev->dev, NULL);
 212         if (IS_ERR(pwm_chip->rstc)) {
 213                 clk_disable_unprepare(pwm_chip->clk);
 214                 return PTR_ERR(pwm_chip->rstc);
 215         }
 216
 217         reset_control_assert(pwm_chip->rstc);
 218         msleep(30);
 219         reset_control_deassert(pwm_chip->rstc);
 220
 221         ret = pwmchip_add(&pwm_chip->chip);
 222         if (ret < 0) {
 223                 clk_disable_unprepare(pwm_chip->clk);
 224                 return ret;
 225         }
 226
 227         for (i = 0; i < pwm_chip->chip.npwm; i++) {
 228                 hibvt_pwm_set_bits(pwm_chip->base, PWM_CTRL_ADDR(i),
 229                                 PWM_KEEP_MASK, (0x1 << PWM_KEEP_SHIFT));
 230         }
 231
 232         platform_set_drvdata(pdev, pwm_chip);
 233
 234         return 0;
 235 }
 236
 237 static int hibvt_pwm_remove(struct platform_device *pdev)
 238 {
 239         struct hibvt_pwm_chip *pwm_chip;
 240
 241         pwm_chip = platform_get_drvdata(pdev);
 242
 243         reset_control_assert(pwm_chip->rstc);
 244         msleep(30);
 245         reset_control_deassert(pwm_chip->rstc);
 246
 247         clk_disable_unprepare(pwm_chip->clk);
 248
 249         return pwmchip_remove(&pwm_chip->chip);
 250 }
 251
 252 static const struct of_device_id hibvt_pwm_of_match[] = {
 253         { .compatible = "hisilicon,hi3516cv300-pwm", .data = &pwm_soc[0] },
 254         { .compatible = "hisilicon,hi3519v100-pwm", .data = &pwm_soc[1] },
 255         {  }
 256 };
 257 MODULE_DEVICE_TABLE(of, hibvt_pwm_of_match);
 258
 259 static struct platform_driver hibvt_pwm_driver = {
 260         .driver = {
 261                 .name = "hibvt-pwm",
 262                 .of_match_table = hibvt_pwm_of_match,
 263         },
 264         .probe = hibvt_pwm_probe,
 265         .remove = hibvt_pwm_remove,
 266 };
 267 module_platform_driver(hibvt_pwm_driver);
 268
 269 MODULE_AUTHOR("Jian Yuan");
 270 MODULE_DESCRIPTION("HiSilicon BVT SoCs PWM driver");
 271 MODULE_LICENSE("GPL");