blob: f1d0b35d277eb2616ada02de08e0da774ed9fec2 [file] [log] [blame]
Heiko Schocherb2f97cf2014-07-18 06:07:19 +02001/*
2 * (C) Copyright 2014
3 * Heiko Schocher, DENX Software Engineering, hs@denx.de.
4 *
5 * Basic support for the pwm modul on imx6.
6 *
7 * Based on linux:drivers/pwm/pwm-imx.c
8 * from
9 * Sascha Hauer <s.hauer@pengutronix.de>
10 *
11 * SPDX-License-Identifier: GPL-2.0
12 */
13
14#include <common.h>
15#include <div64.h>
16#include <asm/arch/imx-regs.h>
17
18/* pwm_id from 0..3 */
19struct pwm_regs *pwm_id_to_reg(int pwm_id)
20{
21 switch (pwm_id) {
22 case 0:
23 return (struct pwm_regs *)PWM1_BASE_ADDR;
24 break;
25 case 1:
26 return (struct pwm_regs *)PWM2_BASE_ADDR;
27 break;
28 case 2:
29 return (struct pwm_regs *)PWM3_BASE_ADDR;
30 break;
31 case 3:
32 return (struct pwm_regs *)PWM4_BASE_ADDR;
33 break;
34 default:
35 printf("unknown pwm_id: %d\n", pwm_id);
36 break;
37 }
38 return NULL;
39}
40
41int pwm_imx_get_parms(int period_ns, int duty_ns, unsigned long *period_c,
42 unsigned long *duty_c, unsigned long *prescale)
43{
44 unsigned long long c;
45
46 /*
47 * we have not yet a clock framework for imx6, so add the clock
48 * value here as a define. Replace it when we have the clock
49 * framework.
50 */
51 c = CONFIG_IMX6_PWM_PER_CLK;
52 c = c * period_ns;
53 do_div(c, 1000000000);
54 *period_c = c;
55
56 *prescale = *period_c / 0x10000 + 1;
57
58 *period_c /= *prescale;
59 c = (unsigned long long)(*period_c * duty_ns);
60 do_div(c, period_ns);
61 *duty_c = c;
62
63 /*
64 * according to imx pwm RM, the real period value should be
65 * PERIOD value in PWMPR plus 2.
66 */
67 if (*period_c > 2)
68 *period_c -= 2;
69 else
70 *period_c = 0;
71
72 return 0;
73}