target/linux/sunxi/patches-3.18/150-pwm-add-sunxi-driver.patch

   1 --- a/drivers/pwm/Kconfig
   2 +++ b/drivers/pwm/Kconfig
   3 @@ -263,6 +263,15 @@ config PWM_STI
   4           To compile this driver as a module, choose M here: the module
   5           will be called pwm-sti.
   6
   7 +config PWM_SUN4I
   8 +       tristate "Allwinner sun4i PWM support"
   9 +       depends on ARCH_SUNXI || COMPILE_TEST
  10 +       help
  11 +         Generic PWM framework driver for Allwinner sun4i and sun7i SoCs.
  12 +
  13 +         To compile this driver as a module, choose M here: the module
  14 +         will be called pwm-sun4i.
  15 +
  16  config PWM_TEGRA
  17         tristate "NVIDIA Tegra PWM support"
  18         depends on ARCH_TEGRA
  19 --- a/drivers/pwm/Makefile
  20 +++ b/drivers/pwm/Makefile
  21 @@ -24,6 +24,7 @@ obj-$(CONFIG_PWM_ROCKCHIP)    += pwm-rockch
  22  obj-$(CONFIG_PWM_SAMSUNG)      += pwm-samsung.o
  23  obj-$(CONFIG_PWM_SPEAR)                += pwm-spear.o
  24  obj-$(CONFIG_PWM_STI)          += pwm-sti.o
  25 +obj-$(CONFIG_PWM_SUN4I)                += pwm-sun4i.o
  26  obj-$(CONFIG_PWM_TEGRA)                += pwm-tegra.o
  27  obj-$(CONFIG_PWM_TIECAP)       += pwm-tiecap.o
  28  obj-$(CONFIG_PWM_TIEHRPWM)     += pwm-tiehrpwm.o
  29 --- /dev/null
  30 +++ b/drivers/pwm/pwm-sun4i.c
  31 @@ -0,0 +1,371 @@
  32 +/*
  33 + * Driver for Allwinner sun4i Pulse Width Modulation Controller
  34 + *
  35 + * Copyright (C) 2014 Alexandre Belloni <alexandre.belloni@free-electrons.com>
  36 + *
  37 + * Licensed under GPLv2.
  38 + */
  39 +
  40 +#include <linux/bitops.h>
  41 +#include <linux/clk.h>
  42 +#include <linux/err.h>
  43 +#include <linux/io.h>
  44 +#include <linux/module.h>
  45 +#include <linux/mutex.h>
  46 +#include <linux/of.h>
  47 +#include <linux/of_device.h>
  48 +#include <linux/platform_device.h>
  49 +#include <linux/pwm.h>
  50 +#include <linux/slab.h>
  51 +#include <linux/time.h>
  52 +
  53 +#define PWM_CTRL_REG           0x0
  54 +
  55 +#define PWM_CH_PRD_BASE                0x4
  56 +#define PWM_CH_PRD_OFFSET      0x4
  57 +#define PWM_CH_PRD(ch)         (PWM_CH_PRD_BASE + PWM_CH_PRD_OFFSET * (ch))
  58 +
  59 +#define PWMCH_OFFSET           15
  60 +#define PWM_PRESCAL_MASK       GENMASK(3, 0)
  61 +#define PWM_PRESCAL_OFF                0
  62 +#define PWM_EN                 BIT(4)
  63 +#define PWM_ACT_STATE          BIT(5)
  64 +#define PWM_CLK_GATING         BIT(6)
  65 +#define PWM_MODE               BIT(7)
  66 +#define PWM_PULSE              BIT(8)
  67 +#define PWM_BYPASS             BIT(9)
  68 +
  69 +#define PWM_RDY_BASE           28
  70 +#define PWM_RDY_OFFSET         1
  71 +#define PWM_RDY(ch)            BIT(PWM_RDY_BASE + PWM_RDY_OFFSET * (ch))
  72 +
  73 +#define PWM_PRD(prd)           (((prd) - 1) << 16)
  74 +#define PWM_PRD_MASK           GENMASK(15, 0)
  75 +
  76 +#define PWM_DTY_MASK           GENMASK(15, 0)
  77 +
  78 +#define BIT_CH(bit, chan)      ((bit) << ((chan) * PWMCH_OFFSET))
  79 +
  80 +static const u32 prescaler_table[] = {
  81 +       120,
  82 +       180,
  83 +       240,
  84 +       360,
  85 +       480,
  86 +       0,
  87 +       0,
  88 +       0,
  89 +       12000,
  90 +       24000,
  91 +       36000,
  92 +       48000,
  93 +       72000,
  94 +       0,
  95 +       0,
  96 +       0, /* Actually 1 but tested separately */
  97 +};
  98 +
  99 +struct sun4i_pwm_data {
 100 +       bool has_prescaler_bypass;
 101 +       bool has_rdy;
 102 +};
 103 +
 104 +struct sun4i_pwm_chip {
 105 +       struct pwm_chip chip;
 106 +       struct clk *clk;
 107 +       void __iomem *base;
 108 +       struct mutex ctrl_lock;
 109 +       const struct sun4i_pwm_data *data;
 110 +};
 111 +
 112 +static inline struct sun4i_pwm_chip *to_sun4i_pwm_chip(struct pwm_chip *chip)
 113 +{
 114 +       return container_of(chip, struct sun4i_pwm_chip, chip);
 115 +}
 116 +
 117 +static inline u32 sun4i_pwm_readl(struct sun4i_pwm_chip *chip,
 118 +                                 unsigned long offset)
 119 +{
 120 +       return readl(chip->base + offset);
 121 +}
 122 +
 123 +static inline void sun4i_pwm_writel(struct sun4i_pwm_chip *chip,
 124 +                                   u32 val, unsigned long offset)
 125 +{
 126 +       writel(val, chip->base + offset);
 127 +}
 128 +
 129 +static int sun4i_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 130 +                           int duty_ns, int period_ns)
 131 +{
 132 +       struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip);
 133 +       u32 clk_rate, prd, dty, val, clk_gate;
 134 +       u64 div = 0;
 135 +       unsigned int prescaler = 0;
 136 +       int err;
 137 +
 138 +       clk_rate = clk_get_rate(sun4i_pwm->clk);
 139 +
 140 +       if (sun4i_pwm->data->has_prescaler_bypass) {
 141 +               /* First, test without any prescaler when available */
 142 +               prescaler = PWM_PRESCAL_MASK;
 143 +               /*
 144 +                * When not using any prescaler, the clock period in nanoseconds
 145 +                * is not an integer so round it half up instead of
 146 +                * truncating to get less surprising values.
 147 +                */
 148 +               div = clk_rate * (u64)period_ns + NSEC_PER_SEC/2;
 149 +               do_div(div, NSEC_PER_SEC);
 150 +               if (div - 1 > PWM_PRD_MASK)
 151 +                       prescaler = 0;
 152 +       }
 153 +
 154 +       if (prescaler == 0) {
 155 +               /* Go up from the first divider */
 156 +               for (prescaler = 0; prescaler < PWM_PRESCAL_MASK; prescaler++) {
 157 +                       if (!prescaler_table[prescaler])
 158 +                               continue;
 159 +                       div = clk_rate / prescaler_table[prescaler];
 160 +                       div = div * (u64)period_ns;
 161 +                       do_div(div, NSEC_PER_SEC);
 162 +                       if (div - 1 <= PWM_PRD_MASK)
 163 +                               break;
 164 +               }
 165 +
 166 +               if (div - 1 > PWM_PRD_MASK) {
 167 +                       dev_err(chip->dev, "period exceeds the maximum value\n");
 168 +                       return -EINVAL;
 169 +               }
 170 +       }
 171 +
 172 +       prd = div;
 173 +       div *= duty_ns;
 174 +       do_div(div, period_ns);
 175 +       dty = div;
 176 +
 177 +       err = clk_prepare_enable(sun4i_pwm->clk);
 178 +       if (err) {
 179 +               dev_err(chip->dev, "failed to enable PWM clock\n");
 180 +               return err;
 181 +       }
 182 +
 183 +       mutex_lock(&sun4i_pwm->ctrl_lock);
 184 +       val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
 185 +
 186 +       if (sun4i_pwm->data->has_rdy && (val & PWM_RDY(pwm->hwpwm))) {
 187 +               mutex_unlock(&sun4i_pwm->ctrl_lock);
 188 +               clk_disable_unprepare(sun4i_pwm->clk);
 189 +               return -EBUSY;
 190 +       }
 191 +
 192 +       clk_gate = val & BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
 193 +       if (clk_gate) {
 194 +               val &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
 195 +               sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
 196 +       }
 197 +
 198 +       val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
 199 +       val &= ~BIT_CH(PWM_PRESCAL_MASK, pwm->hwpwm);
 200 +       val |= BIT_CH(prescaler, pwm->hwpwm);
 201 +       sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
 202 +
 203 +       val = (dty & PWM_DTY_MASK) | PWM_PRD(prd);
 204 +       sun4i_pwm_writel(sun4i_pwm, val, PWM_CH_PRD(pwm->hwpwm));
 205 +
 206 +       if (clk_gate) {
 207 +               val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
 208 +               val |= clk_gate;
 209 +               sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
 210 +       }
 211 +
 212 +       mutex_unlock(&sun4i_pwm->ctrl_lock);
 213 +       clk_disable_unprepare(sun4i_pwm->clk);
 214 +
 215 +       return 0;
 216 +}
 217 +
 218 +static int sun4i_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
 219 +                                 enum pwm_polarity polarity)
 220 +{
 221 +       struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip);
 222 +       u32 val;
 223 +       int ret;
 224 +
 225 +       ret = clk_prepare_enable(sun4i_pwm->clk);
 226 +       if (ret) {
 227 +               dev_err(chip->dev, "failed to enable PWM clock\n");
 228 +               return ret;
 229 +       }
 230 +
 231 +       mutex_lock(&sun4i_pwm->ctrl_lock);
 232 +       val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
 233 +
 234 +       if (polarity != PWM_POLARITY_NORMAL)
 235 +               val &= ~BIT_CH(PWM_ACT_STATE, pwm->hwpwm);
 236 +       else
 237 +               val |= BIT_CH(PWM_ACT_STATE, pwm->hwpwm);
 238 +
 239 +       sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
 240 +
 241 +       mutex_unlock(&sun4i_pwm->ctrl_lock);
 242 +       clk_disable_unprepare(sun4i_pwm->clk);
 243 +
 244 +       return 0;
 245 +}
 246 +
 247 +static int sun4i_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 248 +{
 249 +       struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip);
 250 +       u32 val;
 251 +       int ret;
 252 +
 253 +       ret = clk_prepare_enable(sun4i_pwm->clk);
 254 +       if (ret) {
 255 +               dev_err(chip->dev, "failed to enable PWM clock\n");
 256 +               return ret;
 257 +       }
 258 +
 259 +       mutex_lock(&sun4i_pwm->ctrl_lock);
 260 +       val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
 261 +       val |= BIT_CH(PWM_EN, pwm->hwpwm);
 262 +       val |= BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
 263 +       sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
 264 +       mutex_unlock(&sun4i_pwm->ctrl_lock);
 265 +
 266 +       return 0;
 267 +}
 268 +
 269 +static void sun4i_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 270 +{
 271 +       struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip);
 272 +       u32 val;
 273 +
 274 +       mutex_lock(&sun4i_pwm->ctrl_lock);
 275 +       val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
 276 +       val &= ~BIT_CH(PWM_EN, pwm->hwpwm);
 277 +       val &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
 278 +       sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
 279 +       mutex_unlock(&sun4i_pwm->ctrl_lock);
 280 +
 281 +       clk_disable_unprepare(sun4i_pwm->clk);
 282 +}
 283 +
 284 +static const struct pwm_ops sun4i_pwm_ops = {
 285 +       .config = sun4i_pwm_config,
 286 +       .set_polarity = sun4i_pwm_set_polarity,
 287 +       .enable = sun4i_pwm_enable,
 288 +       .disable = sun4i_pwm_disable,
 289 +       .owner = THIS_MODULE,
 290 +};
 291 +
 292 +static const struct sun4i_pwm_data sun4i_pwm_data_a10 = {
 293 +       .has_prescaler_bypass = false,
 294 +       .has_rdy = false,
 295 +};
 296 +
 297 +static const struct sun4i_pwm_data sun4i_pwm_data_a20 = {
 298 +       .has_prescaler_bypass = true,
 299 +       .has_rdy = true,
 300 +};
 301 +
 302 +static const struct of_device_id sun4i_pwm_dt_ids[] = {
 303 +       {
 304 +               .compatible = "allwinner,sun4i-a10-pwm",
 305 +               .data = &sun4i_pwm_data_a10,
 306 +       }, {
 307 +               .compatible = "allwinner,sun7i-a20-pwm",
 308 +               .data = &sun4i_pwm_data_a20,
 309 +       }, {
 310 +               /* sentinel */
 311 +       },
 312 +};
 313 +MODULE_DEVICE_TABLE(of, sun4i_pwm_dt_ids);
 314 +
 315 +static int sun4i_pwm_probe(struct platform_device *pdev)
 316 +{
 317 +       struct sun4i_pwm_chip *pwm;
 318 +       struct resource *res;
 319 +       u32 val;
 320 +       int i, ret;
 321 +       const struct of_device_id *match;
 322 +
 323 +       match = of_match_device(sun4i_pwm_dt_ids, &pdev->dev);
 324 +
 325 +       pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
 326 +       if (!pwm)
 327 +               return -ENOMEM;
 328 +
 329 +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 330 +       pwm->base = devm_ioremap_resource(&pdev->dev, res);
 331 +       if (IS_ERR(pwm->base))
 332 +               return PTR_ERR(pwm->base);
 333 +
 334 +       pwm->clk = devm_clk_get(&pdev->dev, NULL);
 335 +       if (IS_ERR(pwm->clk))
 336 +               return PTR_ERR(pwm->clk);
 337 +
 338 +       pwm->chip.dev = &pdev->dev;
 339 +       pwm->chip.ops = &sun4i_pwm_ops;
 340 +       pwm->chip.base = -1;
 341 +       pwm->chip.npwm = 2;
 342 +       pwm->chip.can_sleep = true;
 343 +       pwm->chip.of_xlate = of_pwm_xlate_with_flags;
 344 +       pwm->chip.of_pwm_n_cells = 3;
 345 +       pwm->data = match->data;
 346 +
 347 +       mutex_init(&pwm->ctrl_lock);
 348 +
 349 +       ret = pwmchip_add(&pwm->chip);
 350 +       if (ret < 0) {
 351 +               dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
 352 +               goto error;
 353 +       }
 354 +
 355 +       platform_set_drvdata(pdev, pwm);
 356 +
 357 +       ret = clk_prepare_enable(pwm->clk);
 358 +       if (ret) {
 359 +               dev_err(&pdev->dev, "failed to enable PWM clock\n");
 360 +               goto clk_error;
 361 +       }
 362 +
 363 +       val = sun4i_pwm_readl(pwm, PWM_CTRL_REG);
 364 +       for (i = 0; i < pwm->chip.npwm; i++) {
 365 +               if (!(val & BIT_CH(PWM_ACT_STATE, i)))
 366 +                       pwm->chip.pwms[i].polarity = PWM_POLARITY_INVERSED;
 367 +       }
 368 +       clk_disable_unprepare(pwm->clk);
 369 +
 370 +       return 0;
 371 +
 372 +clk_error:
 373 +       pwmchip_remove(&pwm->chip);
 374 +
 375 +error:
 376 +       mutex_destroy(&pwm->ctrl_lock);
 377 +       return ret;
 378 +}
 379 +
 380 +static int sun4i_pwm_remove(struct platform_device *pdev)
 381 +{
 382 +       struct sun4i_pwm_chip *pwm = platform_get_drvdata(pdev);
 383 +
 384 +       mutex_destroy(&pwm->ctrl_lock);
 385 +
 386 +       return pwmchip_remove(&pwm->chip);
 387 +}
 388 +
 389 +static struct platform_driver sun4i_pwm_driver = {
 390 +       .driver = {
 391 +               .name = "sun4i-pwm",
 392 +               .of_match_table = sun4i_pwm_dt_ids,
 393 +       },
 394 +       .probe = sun4i_pwm_probe,
 395 +       .remove = sun4i_pwm_remove,
 396 +};
 397 +module_platform_driver(sun4i_pwm_driver);
 398 +
 399 +MODULE_ALIAS("platform:sun4i-pwm");
 400 +MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
 401 +MODULE_DESCRIPTION("Allwinner sun4i PWM driver");
 402 +MODULE_LICENSE("GPL v2");