blob: 86642004309265a044ff012c15da168e2559d887 [file] [log] [blame]
Simon Glass1564f342012-10-17 13:24:49 +00001/*
Simon Glass142af8c2015-04-14 21:03:22 -06002 * Tegra pulse width frequency modulator definitions
Simon Glass1564f342012-10-17 13:24:49 +00003 *
4 * Copyright (c) 2011 The Chromium OS Authors.
Simon Glass1564f342012-10-17 13:24:49 +00005 *
Wolfgang Denkd79de1d2013-07-08 09:37:19 +02006 * SPDX-License-Identifier: GPL-2.0+
Simon Glass1564f342012-10-17 13:24:49 +00007 */
8
9#include <common.h>
10#include <fdtdec.h>
11#include <asm/io.h>
12#include <asm/arch/clock.h>
13#include <asm/arch/pwm.h>
14
15struct pwm_info {
16 struct pwm_ctlr *pwm; /* Registers for our pwm controller */
17 int pwm_node; /* PWM device tree node */
18} local;
19
20void pwm_enable(unsigned channel, int rate, int pulse_width, int freq_divider)
21{
22 u32 reg;
23
24 assert(channel < PWM_NUM_CHANNELS);
25
26 /* TODO: Can we use clock_adjust_periph_pll_div() here? */
27 clock_start_periph_pll(PERIPH_ID_PWM, CLOCK_ID_SFROM32KHZ, rate);
28
29 reg = PWM_ENABLE_MASK;
30 reg |= pulse_width << PWM_WIDTH_SHIFT;
31 reg |= freq_divider << PWM_DIVIDER_SHIFT;
32 writel(reg, &local.pwm[channel].control);
33 debug("%s: channel=%d, rate=%d\n", __func__, channel, rate);
34}
35
36int pwm_request(const void *blob, int node, const char *prop_name)
37{
38 int pwm_node;
39 u32 data[3];
40
41 if (fdtdec_get_int_array(blob, node, prop_name, data,
42 ARRAY_SIZE(data))) {
43 debug("%s: Cannot decode PWM property '%s'\n", __func__,
44 prop_name);
45 return -1;
46 }
47
48 pwm_node = fdt_node_offset_by_phandle(blob, data[0]);
49 if (pwm_node != local.pwm_node) {
50 debug("%s: PWM property '%s' phandle %d not recognised"
51 "- expecting %d\n", __func__, prop_name, data[0],
52 local.pwm_node);
53 return -1;
54 }
55 if (data[1] >= PWM_NUM_CHANNELS) {
56 debug("%s: PWM property '%s': invalid channel %u\n", __func__,
57 prop_name, data[1]);
58 return -1;
59 }
60
61 /*
62 * TODO: We could maintain a list of requests, but it might not be
63 * worth it for U-Boot.
64 */
65 return data[1];
66}
67
68int pwm_init(const void *blob)
69{
70 local.pwm_node = fdtdec_next_compatible(blob, 0,
71 COMPAT_NVIDIA_TEGRA20_PWM);
72 if (local.pwm_node < 0) {
73 debug("%s: Cannot find device tree node\n", __func__);
74 return -1;
75 }
76
77 local.pwm = (struct pwm_ctlr *)fdtdec_get_addr(blob, local.pwm_node,
78 "reg");
79 if (local.pwm == (struct pwm_ctlr *)FDT_ADDR_T_NONE) {
80 debug("%s: Cannot find pwm reg address\n", __func__);
81 return -1;
82 }
83 debug("Tegra PWM at %p, node %d\n", local.pwm, local.pwm_node);
84
85 return 0;
86}