diff options
Diffstat (limited to 'drivers/pwm/pwm-imx-util.c')
| -rw-r--r-- | drivers/pwm/pwm-imx-util.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-imx-util.c b/drivers/pwm/pwm-imx-util.c new file mode 100644 index 0000000..f1d0b35 --- /dev/null +++ b/drivers/pwm/pwm-imx-util.c @@ -0,0 +1,73 @@ +/* + * (C) Copyright 2014 + * Heiko Schocher, DENX Software Engineering, hs@denx.de. + * + * Basic support for the pwm modul on imx6. + * + * Based on linux:drivers/pwm/pwm-imx.c + * from + * Sascha Hauer <s.hauer@pengutronix.de> + * + * SPDX-License-Identifier: GPL-2.0 + */ + +#include <common.h> +#include <div64.h> +#include <asm/arch/imx-regs.h> + +/* pwm_id from 0..3 */ +struct pwm_regs *pwm_id_to_reg(int pwm_id) +{ + switch (pwm_id) { + case 0: + return (struct pwm_regs *)PWM1_BASE_ADDR; + break; + case 1: + return (struct pwm_regs *)PWM2_BASE_ADDR; + break; + case 2: + return (struct pwm_regs *)PWM3_BASE_ADDR; + break; + case 3: + return (struct pwm_regs *)PWM4_BASE_ADDR; + break; + default: + printf("unknown pwm_id: %d\n", pwm_id); + break; + } + return NULL; +} + +int pwm_imx_get_parms(int period_ns, int duty_ns, unsigned long *period_c, + unsigned long *duty_c, unsigned long *prescale) +{ + unsigned long long c; + + /* + * we have not yet a clock framework for imx6, so add the clock + * value here as a define. Replace it when we have the clock + * framework. + */ + c = CONFIG_IMX6_PWM_PER_CLK; + c = c * period_ns; + do_div(c, 1000000000); + *period_c = c; + + *prescale = *period_c / 0x10000 + 1; + + *period_c /= *prescale; + c = (unsigned long long)(*period_c * duty_ns); + do_div(c, period_ns); + *duty_c = c; + + /* + * according to imx pwm RM, the real period value should be + * PERIOD value in PWMPR plus 2. + */ + if (*period_c > 2) + *period_c -= 2; + else + *period_c = 0; + + return 0; +} |