drivers/pwm/sandbox_pwm.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (c) 2015 Google, Inc
   4  * Written by Simon Glass <sjg@chromium.org>
   5  */
   6
   7 #include <common.h>
   8 #include <dm.h>
   9 #include <errno.h>
  10 #include <pwm.h>
  11 #include <asm/test.h>
  12
  13 enum {
  14         NUM_CHANNELS    = 3,
  15 };
  16
  17 /**
  18  * struct sandbox_pwm_chan - a sandbox PWM channel
  19  *
  20  * @period_ns: Period of the PWM in nanoseconds
  21  * @duty_ns: Current duty cycle of the PWM in nanoseconds
  22  * @enable: true if the PWM is enabled
  23  * @polarity: true if the PWM polarity is active high
  24  */
  25 struct sandbox_pwm_chan {
  26         uint period_ns;
  27         uint duty_ns;
  28         bool enable;
  29         bool polarity;
  30 };
  31
  32 struct sandbox_pwm_priv {
  33         struct sandbox_pwm_chan chan[NUM_CHANNELS];
  34 };
  35
  36 int sandbox_pwm_get_config(struct udevice *dev, uint channel, uint *period_nsp,
  37                            uint *duty_nsp, bool *enablep, bool *polarityp)
  38 {
  39         struct sandbox_pwm_priv *priv = dev_get_priv(dev);
  40         struct sandbox_pwm_chan *chan;
  41
  42         if (channel >= NUM_CHANNELS)
  43                 return -ENOSPC;
  44         chan = &priv->chan[channel];
  45         *period_nsp = chan->period_ns;
  46         *duty_nsp = chan->duty_ns;
  47         *enablep = chan->enable;
  48         *polarityp = chan->polarity;
  49
  50         return 0;
  51 }
  52
  53 static int sandbox_pwm_set_config(struct udevice *dev, uint channel,
  54                                   uint period_ns, uint duty_ns)
  55 {
  56         struct sandbox_pwm_priv *priv = dev_get_priv(dev);
  57         struct sandbox_pwm_chan *chan;
  58
  59         if (channel >= NUM_CHANNELS)
  60                 return -ENOSPC;
  61         chan = &priv->chan[channel];
  62
  63         if (channel == 2) {
  64                 /* Pretend to have some fixed period */
  65                 chan->period_ns = 4096;
  66                 chan->duty_ns =  duty_ns * 4096 / period_ns;
  67         } else {
  68                 chan->period_ns = period_ns;
  69                 chan->duty_ns = duty_ns;
  70         }
  71
  72         return 0;
  73 }
  74
  75 static int sandbox_pwm_set_enable(struct udevice *dev, uint channel,
  76                                   bool enable)
  77 {
  78         struct sandbox_pwm_priv *priv = dev_get_priv(dev);
  79         struct sandbox_pwm_chan *chan;
  80
  81         if (channel >= NUM_CHANNELS)
  82                 return -ENOSPC;
  83         chan = &priv->chan[channel];
  84         chan->enable = enable;
  85
  86         return 0;
  87 }
  88
  89 static int sandbox_pwm_set_invert(struct udevice *dev, uint channel,
  90                                   bool polarity)
  91 {
  92         struct sandbox_pwm_priv *priv = dev_get_priv(dev);
  93         struct sandbox_pwm_chan *chan;
  94
  95         if (channel >= NUM_CHANNELS)
  96                 return -ENOSPC;
  97         chan = &priv->chan[channel];
  98         chan->polarity = polarity;
  99
 100         return 0;
 101 }
 102
 103 static const struct pwm_ops sandbox_pwm_ops = {
 104         .set_config     = sandbox_pwm_set_config,
 105         .set_enable     = sandbox_pwm_set_enable,
 106         .set_invert     = sandbox_pwm_set_invert,
 107 };
 108
 109 static const struct udevice_id sandbox_pwm_ids[] = {
 110         { .compatible = "sandbox,pwm" },
 111         { }
 112 };
 113
 114 U_BOOT_DRIVER(warm_pwm_sandbox) = {
 115         .name           = "pwm_sandbox",
 116         .id             = UCLASS_PWM,
 117         .of_match       = sandbox_pwm_ids,
 118         .ops            = &sandbox_pwm_ops,
 119         .priv_auto      = sizeof(struct sandbox_pwm_priv),
 120 };