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gerrit.devboardsforandroid.linaro.org / platform / external / u-boot / e38cef9f6ef6937934cb5070ad33063ecbf81efa / . / drivers / pwm / exynos_pwm.c
blob: 1c829d286bdd25ac98c0b7f42c99fbdfb1c70cc3 [file] [log] [blame]
Tom Rini83d290c2018-05-06 17:58:06 -0400[diff] [blame]1// SPDX-License-Identifier: GPL-2.0+
Simon Glass5c2dd4c2016-02-21 21:08:49 -0700[diff] [blame]2/*
3 * Copyright 2016 Google Inc.
Simon Glass5c2dd4c2016-02-21 21:08:49 -0700[diff] [blame]4 */
5
6#include <common.h>
7#include <dm.h>
8#include <pwm.h>
9#include <asm/io.h>
10#include <asm/arch/clk.h>
11#include <asm/arch/clock.h>
12#include <asm/arch/pwm.h>
13
Simon Glass5c2dd4c2016-02-21 21:08:49 -0700[diff] [blame]14struct exynos_pwm_priv {
15 struct s5p_timer *regs;
16};
17
18static int exynos_pwm_set_config(struct udevice *dev, uint channel,
19 uint period_ns, uint duty_ns)
20{
21 struct exynos_pwm_priv *priv = dev_get_priv(dev);
22 struct s5p_timer *regs = priv->regs;
23 unsigned int offset, prescaler;
24 uint div = 4, rate, rate_ns;
25 u32 val;
26 u32 tcnt, tcmp, tcon;
27
28 if (channel >= 5)
29 return -EINVAL;
30 debug("%s: Configure '%s' channel %u, period_ns %u, duty_ns %u\n",
31 __func__, dev->name, channel, period_ns, duty_ns);
32
33 val = readl(&regs->tcfg0);
34 prescaler = (channel < 2 ? val : (val >> 8)) & 0xff;
35 div = (readl(&regs->tcfg1) >> MUX_DIV_SHIFT(channel)) & 0xf;
36
37 rate = get_pwm_clk() / ((prescaler + 1) * (1 << div));
38 debug("%s: pwm_clk %lu, rate %u\n", __func__, get_pwm_clk(), rate);
39
40 if (channel < 4) {
41 rate_ns = 1000000000 / rate;
42 tcnt = period_ns / rate_ns;
43 tcmp = duty_ns / rate_ns;
44 debug("%s: tcnt %u, tcmp %u\n", __func__, tcnt, tcmp);
45 offset = channel * 3;
46 writel(tcnt, &regs->tcntb0 + offset);
47 writel(tcmp, &regs->tcmpb0 + offset);
48 }
49
50 tcon = readl(&regs->tcon);
51 tcon |= TCON_UPDATE(channel);
52 if (channel < 4)
53 tcon |= TCON_AUTO_RELOAD(channel);
54 else
55 tcon |= TCON4_AUTO_RELOAD;
56 writel(tcon, &regs->tcon);
57
58 tcon &= ~TCON_UPDATE(channel);
59 writel(tcon, &regs->tcon);
60
61 return 0;
62}
63
64static int exynos_pwm_set_enable(struct udevice *dev, uint channel,
65 bool enable)
66{
67 struct exynos_pwm_priv *priv = dev_get_priv(dev);
68 struct s5p_timer *regs = priv->regs;
69 u32 mask;
70
71 if (channel >= 4)
72 return -EINVAL;
73 debug("%s: Enable '%s' channel %u\n", __func__, dev->name, channel);
74 mask = TCON_START(channel);
75 clrsetbits_le32(&regs->tcon, mask, enable ? mask : 0);
76
77 return 0;
78}
79
80static int exynos_pwm_probe(struct udevice *dev)
81{
82 struct exynos_pwm_priv *priv = dev_get_priv(dev);
83 struct s5p_timer *regs = priv->regs;
84
85 writel(PRESCALER_0 | PRESCALER_1 << 8, &regs->tcfg0);
86
87 return 0;
88}
89
90static int exynos_pwm_ofdata_to_platdata(struct udevice *dev)
91{
92 struct exynos_pwm_priv *priv = dev_get_priv(dev);
93
Simon Glassa821c4a2017-05-17 17:18:05 -0600[diff] [blame]94 priv->regs = (struct s5p_timer *)devfdt_get_addr(dev);
Simon Glass5c2dd4c2016-02-21 21:08:49 -0700[diff] [blame]95
96 return 0;
97}
98
99static const struct pwm_ops exynos_pwm_ops = {
100 .set_config = exynos_pwm_set_config,
101 .set_enable = exynos_pwm_set_enable,
102};
103
104static const struct udevice_id exynos_channels[] = {
105 { .compatible = "samsung,exynos4210-pwm" },
106 { }
107};
108
109U_BOOT_DRIVER(exynos_pwm) = {
110 .name = "exynos_pwm",
111 .id = UCLASS_PWM,
112 .of_match = exynos_channels,
113 .ops = &exynos_pwm_ops,
114 .probe = exynos_pwm_probe,
115 .ofdata_to_platdata = exynos_pwm_ofdata_to_platdata,
116 .priv_auto_alloc_size = sizeof(struct exynos_pwm_priv),
117};