drivers/pwm/sunxi_pwm.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (c) 2017-2018 Vasily Khoruzhick <anarsoul@gmail.com>
   4  */
   5
   6 #include <common.h>
   7 #include <div64.h>
   8 #include <dm.h>
   9 #include <log.h>
  10 #include <pwm.h>
  11 #include <regmap.h>
  12 #include <syscon.h>
  13 #include <asm/global_data.h>
  14 #include <asm/io.h>
  15 #include <asm/arch/pwm.h>
  16 #include <asm/arch/gpio.h>
  17 #include <power/regulator.h>
  18
  19 DECLARE_GLOBAL_DATA_PTR;
  20
  21 #define OSC_24MHZ 24000000
  22
  23 struct sunxi_pwm_priv {
  24         struct sunxi_pwm *regs;
  25         bool invert;
  26         u32 prescaler;
  27 };
  28
  29 static const u32 prescaler_table[] = {
  30         120,    /* 0000 */
  31         180,    /* 0001 */
  32         240,    /* 0010 */
  33         360,    /* 0011 */
  34         480,    /* 0100 */
  35         0,      /* 0101 */
  36         0,      /* 0110 */
  37         0,      /* 0111 */
  38         12000,  /* 1000 */
  39         24000,  /* 1001 */
  40         36000,  /* 1010 */
  41         48000,  /* 1011 */
  42         72000,  /* 1100 */
  43         0,      /* 1101 */
  44         0,      /* 1110 */
  45         1,      /* 1111 */
  46 };
  47
  48 static int sunxi_pwm_config_pinmux(void)
  49 {
  50 #ifdef CONFIG_MACH_SUN50I
  51         sunxi_gpio_set_cfgpin(SUNXI_GPD(22), SUNXI_GPD_PWM);
  52 #endif
  53         return 0;
  54 }
  55
  56 static int sunxi_pwm_set_invert(struct udevice *dev, uint channel,
  57                                 bool polarity)
  58 {
  59         struct sunxi_pwm_priv *priv = dev_get_priv(dev);
  60
  61         debug("%s: polarity=%u\n", __func__, polarity);
  62         priv->invert = polarity;
  63
  64         return 0;
  65 }
  66
  67 static int sunxi_pwm_set_config(struct udevice *dev, uint channel,
  68                                 uint period_ns, uint duty_ns)
  69 {
  70         struct sunxi_pwm_priv *priv = dev_get_priv(dev);
  71         struct sunxi_pwm *regs = priv->regs;
  72         int best_prescaler = 0;
  73         u32 v, best_period = 0, duty;
  74         u64 best_scaled_freq = 0;
  75         const u32 nsecs_per_sec = 1000000000U;
  76
  77         debug("%s: period_ns=%u, duty_ns=%u\n", __func__, period_ns, duty_ns);
  78
  79         for (int prescaler = 0; prescaler <= SUNXI_PWM_CTRL_PRESCALE0_MASK;
  80              prescaler++) {
  81                 u32 period = 0;
  82                 u64 scaled_freq = 0;
  83                 if (!prescaler_table[prescaler])
  84                         continue;
  85                 scaled_freq = lldiv(OSC_24MHZ, prescaler_table[prescaler]);
  86                 period = lldiv(scaled_freq * period_ns, nsecs_per_sec);
  87                 if ((period - 1 <= SUNXI_PWM_CH0_PERIOD_MAX) &&
  88                     best_period < period) {
  89                         best_period = period;
  90                         best_scaled_freq = scaled_freq;
  91                         best_prescaler = prescaler;
  92                 }
  93         }
  94
  95         if (best_period - 1 > SUNXI_PWM_CH0_PERIOD_MAX) {
  96                 debug("%s: failed to find prescaler value\n", __func__);
  97                 return -EINVAL;
  98         }
  99
 100         duty = lldiv(best_scaled_freq * duty_ns, nsecs_per_sec);
 101
 102         if (priv->prescaler != best_prescaler) {
 103                 /* Mask clock to update prescaler */
 104                 v = readl(&regs->ctrl);
 105                 v &= ~SUNXI_PWM_CTRL_CLK_GATE;
 106                 writel(v, &regs->ctrl);
 107                 v &= ~SUNXI_PWM_CTRL_PRESCALE0_MASK;
 108                 v |= (best_prescaler & SUNXI_PWM_CTRL_PRESCALE0_MASK);
 109                 writel(v, &regs->ctrl);
 110                 v |= SUNXI_PWM_CTRL_CLK_GATE;
 111                 writel(v, &regs->ctrl);
 112                 priv->prescaler = best_prescaler;
 113         }
 114
 115         writel(SUNXI_PWM_CH0_PERIOD_PRD(best_period) |
 116                SUNXI_PWM_CH0_PERIOD_DUTY(duty), &regs->ch0_period);
 117
 118         debug("%s: prescaler: %d, period: %d, duty: %d\n",
 119               __func__, priv->prescaler,
 120               best_period, duty);
 121
 122         return 0;
 123 }
 124
 125 static int sunxi_pwm_set_enable(struct udevice *dev, uint channel, bool enable)
 126 {
 127         struct sunxi_pwm_priv *priv = dev_get_priv(dev);
 128         struct sunxi_pwm *regs = priv->regs;
 129         u32 v;
 130
 131         debug("%s: Enable '%s'\n", __func__, dev->name);
 132
 133         v = readl(&regs->ctrl);
 134         if (!enable) {
 135                 v &= ~SUNXI_PWM_CTRL_ENABLE0;
 136                 writel(v, &regs->ctrl);
 137                 return 0;
 138         }
 139
 140         sunxi_pwm_config_pinmux();
 141
 142         if (priv->invert)
 143                 v &= ~SUNXI_PWM_CTRL_CH0_ACT_STA;
 144         else
 145                 v |= SUNXI_PWM_CTRL_CH0_ACT_STA;
 146         v |= SUNXI_PWM_CTRL_ENABLE0;
 147         writel(v, &regs->ctrl);
 148
 149         return 0;
 150 }
 151
 152 static int sunxi_pwm_of_to_plat(struct udevice *dev)
 153 {
 154         struct sunxi_pwm_priv *priv = dev_get_priv(dev);
 155
 156         priv->regs = dev_read_addr_ptr(dev);
 157
 158         return 0;
 159 }
 160
 161 static int sunxi_pwm_probe(struct udevice *dev)
 162 {
 163         return 0;
 164 }
 165
 166 static const struct pwm_ops sunxi_pwm_ops = {
 167         .set_invert     = sunxi_pwm_set_invert,
 168         .set_config     = sunxi_pwm_set_config,
 169         .set_enable     = sunxi_pwm_set_enable,
 170 };
 171
 172 static const struct udevice_id sunxi_pwm_ids[] = {
 173         { .compatible = "allwinner,sun5i-a13-pwm" },
 174         { .compatible = "allwinner,sun50i-a64-pwm" },
 175         { }
 176 };
 177
 178 U_BOOT_DRIVER(sunxi_pwm) = {
 179         .name   = "sunxi_pwm",
 180         .id     = UCLASS_PWM,
 181         .of_match = sunxi_pwm_ids,
 182         .ops    = &sunxi_pwm_ops,
 183         .of_to_plat     = sunxi_pwm_of_to_plat,
 184         .probe          = sunxi_pwm_probe,
 185         .priv_auto      = sizeof(struct sunxi_pwm_priv),
 186 };