Gitiles
Code Review Sign In
gerrit.devboardsforandroid.linaro.org / platform / external / u-boot / fedb428c5beb8776451118f5adc976770a526a33 / . / drivers / pwm / exynos_pwm.c
blob: 9520a14387d9e97e33a10795b8eac424c317a522 [file] [log] [blame]
Simon Glass5c2dd4c2016-02-21 21:08:49 -0700[diff] [blame]1/*
2 * Copyright 2016 Google Inc.
3 *
4 * SPDX-License-Identifier: GPL-2.0+
5 */
6
7#include <common.h>
8#include <dm.h>
9#include <pwm.h>
10#include <asm/io.h>
11#include <asm/arch/clk.h>
12#include <asm/arch/clock.h>
13#include <asm/arch/pwm.h>
14
15DECLARE_GLOBAL_DATA_PTR;
16
17struct exynos_pwm_priv {
18 struct s5p_timer *regs;
19};
20
21static int exynos_pwm_set_config(struct udevice *dev, uint channel,
22 uint period_ns, uint duty_ns)
23{
24 struct exynos_pwm_priv *priv = dev_get_priv(dev);
25 struct s5p_timer *regs = priv->regs;
26 unsigned int offset, prescaler;
27 uint div = 4, rate, rate_ns;
28 u32 val;
29 u32 tcnt, tcmp, tcon;
30
31 if (channel >= 5)
32 return -EINVAL;
33 debug("%s: Configure '%s' channel %u, period_ns %u, duty_ns %u\n",
34 __func__, dev->name, channel, period_ns, duty_ns);
35
36 val = readl(&regs->tcfg0);
37 prescaler = (channel < 2 ? val : (val >> 8)) & 0xff;
38 div = (readl(&regs->tcfg1) >> MUX_DIV_SHIFT(channel)) & 0xf;
39
40 rate = get_pwm_clk() / ((prescaler + 1) * (1 << div));
41 debug("%s: pwm_clk %lu, rate %u\n", __func__, get_pwm_clk(), rate);
42
43 if (channel < 4) {
44 rate_ns = 1000000000 / rate;
45 tcnt = period_ns / rate_ns;
46 tcmp = duty_ns / rate_ns;
47 debug("%s: tcnt %u, tcmp %u\n", __func__, tcnt, tcmp);
48 offset = channel * 3;
49 writel(tcnt, &regs->tcntb0 + offset);
50 writel(tcmp, &regs->tcmpb0 + offset);
51 }
52
53 tcon = readl(&regs->tcon);
54 tcon |= TCON_UPDATE(channel);
55 if (channel < 4)
56 tcon |= TCON_AUTO_RELOAD(channel);
57 else
58 tcon |= TCON4_AUTO_RELOAD;
59 writel(tcon, &regs->tcon);
60
61 tcon &= ~TCON_UPDATE(channel);
62 writel(tcon, &regs->tcon);
63
64 return 0;
65}
66
67static int exynos_pwm_set_enable(struct udevice *dev, uint channel,
68 bool enable)
69{
70 struct exynos_pwm_priv *priv = dev_get_priv(dev);
71 struct s5p_timer *regs = priv->regs;
72 u32 mask;
73
74 if (channel >= 4)
75 return -EINVAL;
76 debug("%s: Enable '%s' channel %u\n", __func__, dev->name, channel);
77 mask = TCON_START(channel);
78 clrsetbits_le32(&regs->tcon, mask, enable ? mask : 0);
79
80 return 0;
81}
82
83static int exynos_pwm_probe(struct udevice *dev)
84{
85 struct exynos_pwm_priv *priv = dev_get_priv(dev);
86 struct s5p_timer *regs = priv->regs;
87
88 writel(PRESCALER_0 | PRESCALER_1 << 8, &regs->tcfg0);
89
90 return 0;
91}
92
93static int exynos_pwm_ofdata_to_platdata(struct udevice *dev)
94{
95 struct exynos_pwm_priv *priv = dev_get_priv(dev);
96
Simon Glassa821c4a2017-05-17 17:18:05 -0600[diff] [blame]97 priv->regs = (struct s5p_timer *)devfdt_get_addr(dev);
Simon Glass5c2dd4c2016-02-21 21:08:49 -0700[diff] [blame]98
99 return 0;
100}
101
102static const struct pwm_ops exynos_pwm_ops = {
103 .set_config = exynos_pwm_set_config,
104 .set_enable = exynos_pwm_set_enable,
105};
106
107static const struct udevice_id exynos_channels[] = {
108 { .compatible = "samsung,exynos4210-pwm" },
109 { }
110};
111
112U_BOOT_DRIVER(exynos_pwm) = {
113 .name = "exynos_pwm",
114 .id = UCLASS_PWM,
115 .of_match = exynos_channels,
116 .ops = &exynos_pwm_ops,
117 .probe = exynos_pwm_probe,
118 .ofdata_to_platdata = exynos_pwm_ofdata_to_platdata,
119 .priv_auto_alloc_size = sizeof(struct exynos_pwm_priv),
120};