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97d0b42e39
Add PM support for FTM PWM driver using callback function suspend and resume in .driver.pm of platform_driver. Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
557 lines
12 KiB
C
557 lines
12 KiB
C
/*
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* Freescale FlexTimer Module (FTM) PWM Driver
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*
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* Copyright 2012-2013 Freescale Semiconductor, Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <linux/clk.h>
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#include <linux/err.h>
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/of_address.h>
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#include <linux/platform_device.h>
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#include <linux/pm.h>
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#include <linux/pwm.h>
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#include <linux/regmap.h>
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#include <linux/slab.h>
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#define FTM_SC 0x00
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#define FTM_SC_CLK_MASK_SHIFT 3
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#define FTM_SC_CLK_MASK (3 << FTM_SC_CLK_MASK_SHIFT)
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#define FTM_SC_CLK(c) (((c) + 1) << FTM_SC_CLK_MASK_SHIFT)
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#define FTM_SC_PS_MASK 0x7
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#define FTM_CNT 0x04
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#define FTM_MOD 0x08
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#define FTM_CSC_BASE 0x0C
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#define FTM_CSC_MSB BIT(5)
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#define FTM_CSC_MSA BIT(4)
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#define FTM_CSC_ELSB BIT(3)
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#define FTM_CSC_ELSA BIT(2)
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#define FTM_CSC(_channel) (FTM_CSC_BASE + ((_channel) * 8))
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#define FTM_CV_BASE 0x10
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#define FTM_CV(_channel) (FTM_CV_BASE + ((_channel) * 8))
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#define FTM_CNTIN 0x4C
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#define FTM_STATUS 0x50
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#define FTM_MODE 0x54
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#define FTM_MODE_FTMEN BIT(0)
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#define FTM_MODE_INIT BIT(2)
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#define FTM_MODE_PWMSYNC BIT(3)
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#define FTM_SYNC 0x58
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#define FTM_OUTINIT 0x5C
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#define FTM_OUTMASK 0x60
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#define FTM_COMBINE 0x64
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#define FTM_DEADTIME 0x68
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#define FTM_EXTTRIG 0x6C
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#define FTM_POL 0x70
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#define FTM_FMS 0x74
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#define FTM_FILTER 0x78
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#define FTM_FLTCTRL 0x7C
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#define FTM_QDCTRL 0x80
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#define FTM_CONF 0x84
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#define FTM_FLTPOL 0x88
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#define FTM_SYNCONF 0x8C
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#define FTM_INVCTRL 0x90
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#define FTM_SWOCTRL 0x94
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#define FTM_PWMLOAD 0x98
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enum fsl_pwm_clk {
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FSL_PWM_CLK_SYS,
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FSL_PWM_CLK_FIX,
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FSL_PWM_CLK_EXT,
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FSL_PWM_CLK_CNTEN,
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FSL_PWM_CLK_MAX
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};
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struct fsl_pwm_chip {
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struct pwm_chip chip;
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struct mutex lock;
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unsigned int use_count;
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unsigned int cnt_select;
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unsigned int clk_ps;
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struct regmap *regmap;
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int period_ns;
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struct clk *clk[FSL_PWM_CLK_MAX];
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};
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static inline struct fsl_pwm_chip *to_fsl_chip(struct pwm_chip *chip)
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{
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return container_of(chip, struct fsl_pwm_chip, chip);
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}
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static int fsl_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
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return clk_prepare_enable(fpc->clk[FSL_PWM_CLK_SYS]);
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}
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static void fsl_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
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clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_SYS]);
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}
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static int fsl_pwm_calculate_default_ps(struct fsl_pwm_chip *fpc,
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enum fsl_pwm_clk index)
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{
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unsigned long sys_rate, cnt_rate;
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unsigned long long ratio;
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sys_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_SYS]);
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if (!sys_rate)
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return -EINVAL;
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cnt_rate = clk_get_rate(fpc->clk[fpc->cnt_select]);
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if (!cnt_rate)
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return -EINVAL;
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switch (index) {
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case FSL_PWM_CLK_SYS:
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fpc->clk_ps = 1;
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break;
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case FSL_PWM_CLK_FIX:
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ratio = 2 * cnt_rate - 1;
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do_div(ratio, sys_rate);
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fpc->clk_ps = ratio;
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break;
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case FSL_PWM_CLK_EXT:
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ratio = 4 * cnt_rate - 1;
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do_div(ratio, sys_rate);
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fpc->clk_ps = ratio;
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break;
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default:
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return -EINVAL;
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}
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return 0;
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}
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static unsigned long fsl_pwm_calculate_cycles(struct fsl_pwm_chip *fpc,
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unsigned long period_ns)
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{
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unsigned long long c, c0;
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c = clk_get_rate(fpc->clk[fpc->cnt_select]);
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c = c * period_ns;
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do_div(c, 1000000000UL);
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do {
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c0 = c;
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do_div(c0, (1 << fpc->clk_ps));
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if (c0 <= 0xFFFF)
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return (unsigned long)c0;
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} while (++fpc->clk_ps < 8);
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return 0;
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}
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static unsigned long fsl_pwm_calculate_period_cycles(struct fsl_pwm_chip *fpc,
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unsigned long period_ns,
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enum fsl_pwm_clk index)
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{
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int ret;
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ret = fsl_pwm_calculate_default_ps(fpc, index);
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if (ret) {
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dev_err(fpc->chip.dev,
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"failed to calculate default prescaler: %d\n",
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ret);
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return 0;
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}
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return fsl_pwm_calculate_cycles(fpc, period_ns);
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}
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static unsigned long fsl_pwm_calculate_period(struct fsl_pwm_chip *fpc,
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unsigned long period_ns)
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{
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enum fsl_pwm_clk m0, m1;
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unsigned long fix_rate, ext_rate, cycles;
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cycles = fsl_pwm_calculate_period_cycles(fpc, period_ns,
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FSL_PWM_CLK_SYS);
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if (cycles) {
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fpc->cnt_select = FSL_PWM_CLK_SYS;
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return cycles;
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}
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fix_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_FIX]);
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ext_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_EXT]);
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if (fix_rate > ext_rate) {
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m0 = FSL_PWM_CLK_FIX;
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m1 = FSL_PWM_CLK_EXT;
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} else {
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m0 = FSL_PWM_CLK_EXT;
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m1 = FSL_PWM_CLK_FIX;
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}
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cycles = fsl_pwm_calculate_period_cycles(fpc, period_ns, m0);
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if (cycles) {
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fpc->cnt_select = m0;
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return cycles;
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}
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fpc->cnt_select = m1;
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return fsl_pwm_calculate_period_cycles(fpc, period_ns, m1);
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}
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static unsigned long fsl_pwm_calculate_duty(struct fsl_pwm_chip *fpc,
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unsigned long period_ns,
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unsigned long duty_ns)
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{
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unsigned long long duty;
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u32 val;
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regmap_read(fpc->regmap, FTM_MOD, &val);
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duty = (unsigned long long)duty_ns * (val + 1);
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do_div(duty, period_ns);
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return (unsigned long)duty;
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}
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static int fsl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
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int duty_ns, int period_ns)
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{
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struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
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u32 period, duty;
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mutex_lock(&fpc->lock);
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/*
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* The Freescale FTM controller supports only a single period for
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* all PWM channels, therefore incompatible changes need to be
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* refused.
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*/
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if (fpc->period_ns && fpc->period_ns != period_ns) {
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dev_err(fpc->chip.dev,
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"conflicting period requested for PWM %u\n",
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pwm->hwpwm);
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mutex_unlock(&fpc->lock);
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return -EBUSY;
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}
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if (!fpc->period_ns && duty_ns) {
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period = fsl_pwm_calculate_period(fpc, period_ns);
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if (!period) {
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dev_err(fpc->chip.dev, "failed to calculate period\n");
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mutex_unlock(&fpc->lock);
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return -EINVAL;
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}
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regmap_update_bits(fpc->regmap, FTM_SC, FTM_SC_PS_MASK,
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fpc->clk_ps);
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regmap_write(fpc->regmap, FTM_MOD, period - 1);
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fpc->period_ns = period_ns;
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}
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mutex_unlock(&fpc->lock);
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duty = fsl_pwm_calculate_duty(fpc, period_ns, duty_ns);
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regmap_write(fpc->regmap, FTM_CSC(pwm->hwpwm),
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FTM_CSC_MSB | FTM_CSC_ELSB);
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regmap_write(fpc->regmap, FTM_CV(pwm->hwpwm), duty);
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return 0;
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}
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static int fsl_pwm_set_polarity(struct pwm_chip *chip,
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struct pwm_device *pwm,
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enum pwm_polarity polarity)
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{
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struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
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u32 val;
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regmap_read(fpc->regmap, FTM_POL, &val);
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if (polarity == PWM_POLARITY_INVERSED)
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val |= BIT(pwm->hwpwm);
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else
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val &= ~BIT(pwm->hwpwm);
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regmap_write(fpc->regmap, FTM_POL, val);
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return 0;
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}
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static int fsl_counter_clock_enable(struct fsl_pwm_chip *fpc)
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{
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int ret;
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if (fpc->use_count++ != 0)
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return 0;
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/* select counter clock source */
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regmap_update_bits(fpc->regmap, FTM_SC, FTM_SC_CLK_MASK,
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FTM_SC_CLK(fpc->cnt_select));
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ret = clk_prepare_enable(fpc->clk[fpc->cnt_select]);
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if (ret)
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return ret;
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ret = clk_prepare_enable(fpc->clk[FSL_PWM_CLK_CNTEN]);
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if (ret) {
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clk_disable_unprepare(fpc->clk[fpc->cnt_select]);
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return ret;
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}
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return 0;
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}
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static int fsl_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
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int ret;
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mutex_lock(&fpc->lock);
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regmap_update_bits(fpc->regmap, FTM_OUTMASK, BIT(pwm->hwpwm), 0);
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ret = fsl_counter_clock_enable(fpc);
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mutex_unlock(&fpc->lock);
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return ret;
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}
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static void fsl_counter_clock_disable(struct fsl_pwm_chip *fpc)
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{
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/*
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* already disabled, do nothing
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*/
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if (fpc->use_count == 0)
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return;
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/* there are still users, so can't disable yet */
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if (--fpc->use_count > 0)
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return;
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/* no users left, disable PWM counter clock */
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regmap_update_bits(fpc->regmap, FTM_SC, FTM_SC_CLK_MASK, 0);
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clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_CNTEN]);
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clk_disable_unprepare(fpc->clk[fpc->cnt_select]);
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}
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static void fsl_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
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u32 val;
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mutex_lock(&fpc->lock);
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regmap_update_bits(fpc->regmap, FTM_OUTMASK, BIT(pwm->hwpwm),
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BIT(pwm->hwpwm));
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fsl_counter_clock_disable(fpc);
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regmap_read(fpc->regmap, FTM_OUTMASK, &val);
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if ((val & 0xFF) == 0xFF)
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fpc->period_ns = 0;
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mutex_unlock(&fpc->lock);
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}
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static const struct pwm_ops fsl_pwm_ops = {
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.request = fsl_pwm_request,
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.free = fsl_pwm_free,
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.config = fsl_pwm_config,
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.set_polarity = fsl_pwm_set_polarity,
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.enable = fsl_pwm_enable,
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.disable = fsl_pwm_disable,
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.owner = THIS_MODULE,
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};
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static int fsl_pwm_init(struct fsl_pwm_chip *fpc)
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{
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int ret;
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ret = clk_prepare_enable(fpc->clk[FSL_PWM_CLK_SYS]);
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if (ret)
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return ret;
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regmap_write(fpc->regmap, FTM_CNTIN, 0x00);
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regmap_write(fpc->regmap, FTM_OUTINIT, 0x00);
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regmap_write(fpc->regmap, FTM_OUTMASK, 0xFF);
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clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_SYS]);
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return 0;
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}
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static bool fsl_pwm_volatile_reg(struct device *dev, unsigned int reg)
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{
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switch (reg) {
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case FTM_CNT:
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return true;
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}
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return false;
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}
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static const struct regmap_config fsl_pwm_regmap_config = {
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.reg_bits = 32,
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.reg_stride = 4,
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.val_bits = 32,
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.max_register = FTM_PWMLOAD,
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.volatile_reg = fsl_pwm_volatile_reg,
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.cache_type = REGCACHE_RBTREE,
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};
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static int fsl_pwm_probe(struct platform_device *pdev)
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{
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struct fsl_pwm_chip *fpc;
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struct resource *res;
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void __iomem *base;
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int ret;
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fpc = devm_kzalloc(&pdev->dev, sizeof(*fpc), GFP_KERNEL);
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if (!fpc)
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return -ENOMEM;
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mutex_init(&fpc->lock);
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fpc->chip.dev = &pdev->dev;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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base = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(base))
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return PTR_ERR(base);
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fpc->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "ftm_sys", base,
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&fsl_pwm_regmap_config);
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if (IS_ERR(fpc->regmap)) {
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dev_err(&pdev->dev, "regmap init failed\n");
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return PTR_ERR(fpc->regmap);
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}
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fpc->clk[FSL_PWM_CLK_SYS] = devm_clk_get(&pdev->dev, "ftm_sys");
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if (IS_ERR(fpc->clk[FSL_PWM_CLK_SYS])) {
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dev_err(&pdev->dev, "failed to get \"ftm_sys\" clock\n");
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return PTR_ERR(fpc->clk[FSL_PWM_CLK_SYS]);
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}
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fpc->clk[FSL_PWM_CLK_FIX] = devm_clk_get(fpc->chip.dev, "ftm_fix");
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if (IS_ERR(fpc->clk[FSL_PWM_CLK_FIX]))
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return PTR_ERR(fpc->clk[FSL_PWM_CLK_FIX]);
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fpc->clk[FSL_PWM_CLK_EXT] = devm_clk_get(fpc->chip.dev, "ftm_ext");
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if (IS_ERR(fpc->clk[FSL_PWM_CLK_EXT]))
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return PTR_ERR(fpc->clk[FSL_PWM_CLK_EXT]);
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fpc->clk[FSL_PWM_CLK_CNTEN] =
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devm_clk_get(fpc->chip.dev, "ftm_cnt_clk_en");
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if (IS_ERR(fpc->clk[FSL_PWM_CLK_CNTEN]))
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return PTR_ERR(fpc->clk[FSL_PWM_CLK_CNTEN]);
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fpc->chip.ops = &fsl_pwm_ops;
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fpc->chip.of_xlate = of_pwm_xlate_with_flags;
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fpc->chip.of_pwm_n_cells = 3;
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fpc->chip.base = -1;
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fpc->chip.npwm = 8;
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fpc->chip.can_sleep = true;
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ret = pwmchip_add(&fpc->chip);
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if (ret < 0) {
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dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
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return ret;
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}
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platform_set_drvdata(pdev, fpc);
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return fsl_pwm_init(fpc);
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}
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static int fsl_pwm_remove(struct platform_device *pdev)
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{
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struct fsl_pwm_chip *fpc = platform_get_drvdata(pdev);
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return pwmchip_remove(&fpc->chip);
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}
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#ifdef CONFIG_PM_SLEEP
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static int fsl_pwm_suspend(struct device *dev)
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{
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struct fsl_pwm_chip *fpc = dev_get_drvdata(dev);
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u32 val;
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|
|
|
regcache_cache_only(fpc->regmap, true);
|
|
regcache_mark_dirty(fpc->regmap);
|
|
|
|
/* read from cache */
|
|
regmap_read(fpc->regmap, FTM_OUTMASK, &val);
|
|
if ((val & 0xFF) != 0xFF) {
|
|
clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_CNTEN]);
|
|
clk_disable_unprepare(fpc->clk[fpc->cnt_select]);
|
|
clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_SYS]);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int fsl_pwm_resume(struct device *dev)
|
|
{
|
|
struct fsl_pwm_chip *fpc = dev_get_drvdata(dev);
|
|
u32 val;
|
|
|
|
/* read from cache */
|
|
regmap_read(fpc->regmap, FTM_OUTMASK, &val);
|
|
if ((val & 0xFF) != 0xFF) {
|
|
clk_prepare_enable(fpc->clk[FSL_PWM_CLK_SYS]);
|
|
clk_prepare_enable(fpc->clk[fpc->cnt_select]);
|
|
clk_prepare_enable(fpc->clk[FSL_PWM_CLK_CNTEN]);
|
|
}
|
|
|
|
/* restore all registers from cache */
|
|
regcache_cache_only(fpc->regmap, false);
|
|
regcache_sync(fpc->regmap);
|
|
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static const struct dev_pm_ops fsl_pwm_pm_ops = {
|
|
SET_SYSTEM_SLEEP_PM_OPS(fsl_pwm_suspend, fsl_pwm_resume)
|
|
};
|
|
|
|
static const struct of_device_id fsl_pwm_dt_ids[] = {
|
|
{ .compatible = "fsl,vf610-ftm-pwm", },
|
|
{ /* sentinel */ }
|
|
};
|
|
MODULE_DEVICE_TABLE(of, fsl_pwm_dt_ids);
|
|
|
|
static struct platform_driver fsl_pwm_driver = {
|
|
.driver = {
|
|
.name = "fsl-ftm-pwm",
|
|
.of_match_table = fsl_pwm_dt_ids,
|
|
.pm = &fsl_pwm_pm_ops,
|
|
},
|
|
.probe = fsl_pwm_probe,
|
|
.remove = fsl_pwm_remove,
|
|
};
|
|
module_platform_driver(fsl_pwm_driver);
|
|
|
|
MODULE_DESCRIPTION("Freescale FlexTimer Module PWM Driver");
|
|
MODULE_AUTHOR("Xiubo Li <Li.Xiubo@freescale.com>");
|
|
MODULE_ALIAS("platform:fsl-ftm-pwm");
|
|
MODULE_LICENSE("GPL");
|