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gerrit.devboardsforandroid.linaro.org / platform / external / u-boot / 105da6251a16cfc5db1ef374b5a18ea8df6e8a4c / . / drivers / pwm / exynos_pwm.c
blob: fed1583796af59fde7a07c4d24a3c17f15aba2f1 [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>
Simon Glassf7ae49f2020-05-10 11:40:05 -0600[diff] [blame]8#include <log.h>
Simon Glass5c2dd4c2016-02-21 21:08:49 -0700[diff] [blame]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
Simon Glass5c2dd4c2016-02-21 21:08:49 -0700[diff] [blame]15struct exynos_pwm_priv {
16 struct s5p_timer *regs;
17};
18
19static int exynos_pwm_set_config(struct udevice *dev, uint channel,
20 uint period_ns, uint duty_ns)
21{
22 struct exynos_pwm_priv *priv = dev_get_priv(dev);
23 struct s5p_timer *regs = priv->regs;
24 unsigned int offset, prescaler;
25 uint div = 4, rate, rate_ns;
26 u32 val;
27 u32 tcnt, tcmp, tcon;
28
29 if (channel >= 5)
30 return -EINVAL;
31 debug("%s: Configure '%s' channel %u, period_ns %u, duty_ns %u\n",
32 __func__, dev->name, channel, period_ns, duty_ns);
33
34 val = readl(&regs->tcfg0);
35 prescaler = (channel < 2 ? val : (val >> 8)) & 0xff;
36 div = (readl(&regs->tcfg1) >> MUX_DIV_SHIFT(channel)) & 0xf;
37
38 rate = get_pwm_clk() / ((prescaler + 1) * (1 << div));
39 debug("%s: pwm_clk %lu, rate %u\n", __func__, get_pwm_clk(), rate);
40
41 if (channel < 4) {
42 rate_ns = 1000000000 / rate;
43 tcnt = period_ns / rate_ns;
44 tcmp = duty_ns / rate_ns;
45 debug("%s: tcnt %u, tcmp %u\n", __func__, tcnt, tcmp);
46 offset = channel * 3;
47 writel(tcnt, &regs->tcntb0 + offset);
48 writel(tcmp, &regs->tcmpb0 + offset);
49 }
50
51 tcon = readl(&regs->tcon);
52 tcon |= TCON_UPDATE(channel);
53 if (channel < 4)
54 tcon |= TCON_AUTO_RELOAD(channel);
55 else
56 tcon |= TCON4_AUTO_RELOAD;
57 writel(tcon, &regs->tcon);
58
59 tcon &= ~TCON_UPDATE(channel);
60 writel(tcon, &regs->tcon);
61
62 return 0;
63}
64
65static int exynos_pwm_set_enable(struct udevice *dev, uint channel,
66 bool enable)
67{
68 struct exynos_pwm_priv *priv = dev_get_priv(dev);
69 struct s5p_timer *regs = priv->regs;
70 u32 mask;
71
72 if (channel >= 4)
73 return -EINVAL;
74 debug("%s: Enable '%s' channel %u\n", __func__, dev->name, channel);
75 mask = TCON_START(channel);
76 clrsetbits_le32(&regs->tcon, mask, enable ? mask : 0);
77
78 return 0;
79}
80
81static int exynos_pwm_probe(struct udevice *dev)
82{
83 struct exynos_pwm_priv *priv = dev_get_priv(dev);
84 struct s5p_timer *regs = priv->regs;
85
86 writel(PRESCALER_0 | PRESCALER_1 << 8, &regs->tcfg0);
87
88 return 0;
89}
90
91static int exynos_pwm_ofdata_to_platdata(struct udevice *dev)
92{
93 struct exynos_pwm_priv *priv = dev_get_priv(dev);
94
Simon Glassa821c4a2017-05-17 17:18:05 -0600[diff] [blame]95 priv->regs = (struct s5p_timer *)devfdt_get_addr(dev);
Simon Glass5c2dd4c2016-02-21 21:08:49 -0700[diff] [blame]96
97 return 0;
98}
99
100static const struct pwm_ops exynos_pwm_ops = {
101 .set_config = exynos_pwm_set_config,
102 .set_enable = exynos_pwm_set_enable,
103};
104
105static const struct udevice_id exynos_channels[] = {
106 { .compatible = "samsung,exynos4210-pwm" },
107 { }
108};
109
110U_BOOT_DRIVER(exynos_pwm) = {
111 .name = "exynos_pwm",
112 .id = UCLASS_PWM,
113 .of_match = exynos_channels,
114 .ops = &exynos_pwm_ops,
115 .probe = exynos_pwm_probe,
116 .ofdata_to_platdata = exynos_pwm_ofdata_to_platdata,
117 .priv_auto_alloc_size = sizeof(struct exynos_pwm_priv),
118};