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pwm: qpnp: provide both nsec/usec-supported pwm config() functions 

Kernel 3.10 introduces pwm framework, and the standard pwm_config()
API uses nanosecond-level parameters, so we should implement it.

But Qualcomm platform should support 384 seconds pwm-period at most,
the above standard API couldn't satisfy the requirement of the bigger
period, so we also provide pwm_config_us() this such platform related
API.

CRs-Fixed: 587715
Change-Id: Ia3ea9904141f69c1f40a8619ba8d9fe891e3460a
Signed-off-by: Xu Kai <kaixu@codeaurora.org>
This commit is contained in:
Xu Kai 2013-12-04 18:25:30 +08:00
parent 2c8ba2e740
commit 82d4c56831
2 changed files with 107 additions and 41 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

136
drivers/pwm/pwm-qpnp.c
View File

@ -197,6 +197,12 @@ do { \
#define QPNP_PWM_SIZE_7_8_BIT 0x6
#define QPNP_PWM_SIZE_6_7_9_BIT 0xB
/* Supported time levels */
enum time_level {
LVL_NSEC,
LVL_USEC,
};
/* LPG revisions */
enum qpnp_lpg_revision {
QPNP_LPG_REVISION_0 = 0x0,
@ -290,7 +296,8 @@ struct qpnp_lpg_config {
struct _qpnp_pwm_config {
int pwm_value;
int pwm_duty;
int pwm_period; /* in microseconds */
int pwm_duty; /* in microseconds */
struct pwm_period_config period;
int supported_sizes;
int force_pwm_size;
@ -420,7 +427,8 @@ static int qpnp_lpg_save_and_write(u8 value, u8 mask, u8 *reg, u16 addr,
* This is the formula to figure out m for the best pre-divide and clock:
* (PWM Period / N) = (Pre-divide * Clock Period) * 2^m
*/
static void qpnp_lpg_calc_period(unsigned int period_us,
static void qpnp_lpg_calc_period(enum time_level tm_lvl,
unsigned int period_value,
struct qpnp_pwm_chip *chip)
{
int n, m, clk, div;
@ -437,14 +445,18 @@ static void qpnp_lpg_calc_period(unsigned int period_us,
else
n = 6;
if (period_us < ((unsigned)(-1) / NSEC_PER_USEC)) {
period_n = (period_us * NSEC_PER_USEC) >> n;
if (tm_lvl == LVL_USEC) {
if (period_value < ((unsigned)(-1) / NSEC_PER_USEC)) {
period_n = (period_value * NSEC_PER_USEC) >> n;
} else {
if (supported_sizes == QPNP_PWM_SIZE_7_8_BIT)
n = 8;
else
n = 9;
period_n = (period_value >> n) * NSEC_PER_USEC;
}
} else {
if (supported_sizes == QPNP_PWM_SIZE_7_8_BIT)
n = 8;
else
n = 9;
period_n = (period_us >> n) * NSEC_PER_USEC;
period_n = period_value >> n;
}
if (force_pwm_size != 0) {
@ -515,19 +527,19 @@ static void qpnp_lpg_calc_period(unsigned int period_us,
}
static void qpnp_lpg_calc_pwm_value(struct _qpnp_pwm_config *pwm_config,
unsigned int period_us,
unsigned int duty_us)
unsigned int period_value,
unsigned int duty_value)
{
unsigned int max_pwm_value, tmp;
/* Figure out pwm_value with overflow handling */
tmp = 1 << (sizeof(tmp) * 8 - pwm_config->period.pwm_size);
if (duty_us < tmp) {
tmp = duty_us << pwm_config->period.pwm_size;
pwm_config->pwm_value = tmp / period_us;
if (duty_value < tmp) {
tmp = duty_value << pwm_config->period.pwm_size;
pwm_config->pwm_value = tmp / period_value;
} else {
tmp = period_us >> pwm_config->period.pwm_size;
pwm_config->pwm_value = duty_us / tmp;
tmp = period_value >> pwm_config->period.pwm_size;
pwm_config->pwm_value = duty_value / tmp;
}
max_pwm_value = (1 << pwm_config->period.pwm_size) - 1;
if (pwm_config->pwm_value > max_pwm_value)
@ -1068,14 +1080,16 @@ out:
}
static int _pwm_config(struct qpnp_pwm_chip *chip,
int duty_us, int period_us)
enum time_level tm_lvl,
int duty_value, int period_value)
{
int rc;
struct _qpnp_pwm_config *pwm_config = &chip->pwm_config;
struct pwm_period_config *period = &pwm_config->period;
pwm_config->pwm_duty = duty_us;
qpnp_lpg_calc_pwm_value(pwm_config, period_us, duty_us);
pwm_config->pwm_duty = (tm_lvl == LVL_USEC) ? duty_value :
duty_value / NSEC_PER_USEC;
qpnp_lpg_calc_pwm_value(pwm_config, period_value, duty_value);
rc = qpnp_lpg_save_pwm_value(chip);
if (rc)
goto out;
@ -1086,8 +1100,9 @@ static int _pwm_config(struct qpnp_pwm_chip *chip,
if (rc)
goto out;
pr_debug("duty/period=%u/%u usec: pwm_value=%d (of %d)\n",
(unsigned)duty_us, (unsigned)period_us,
pr_debug("duty/period=%u/%u %s: pwm_value=%d (of %d)\n",
(unsigned)duty_value, (unsigned)period_value,
(tm_lvl == LVL_USEC) ? "usec" : "nsec",
pwm_config->pwm_value, 1 << period->pwm_size);
out:
@ -1185,7 +1200,7 @@ static int _pwm_enable(struct qpnp_pwm_chip *chip)
* @pwm_chip: the PWM chip
* @pwm: the PWM device
*/
void qpnp_pwm_free(struct pwm_chip *pwm_chip,
static void qpnp_pwm_free(struct pwm_chip *pwm_chip,
struct pwm_device *pwm)
{
struct qpnp_pwm_chip *chip = qpnp_pwm_from_pwm_chip(pwm_chip);
@ -1203,31 +1218,31 @@ void qpnp_pwm_free(struct pwm_chip *pwm_chip,
/**
* qpnp_pwm_config - change a PWM device configuration
* @pwm: the PWM device
* @period_us: period in microseconds
* @duty_us: duty cycle in microseconds
* @period_ns: period in nanoseconds
* @duty_ns: duty cycle in nanoseconds
*/
int qpnp_pwm_config(struct pwm_chip *pwm_chip,
struct pwm_device *pwm, int duty_us, int period_us)
static int qpnp_pwm_config(struct pwm_chip *pwm_chip,
struct pwm_device *pwm, int duty_ns, int period_ns)
{
int rc;
unsigned long flags;
struct qpnp_pwm_chip *chip = qpnp_pwm_from_pwm_chip(pwm_chip);
if ((unsigned)period_us > PM_PWM_PERIOD_MAX ||
(unsigned)period_us < PM_PWM_PERIOD_MIN) {
if ((unsigned)period_ns < PM_PWM_PERIOD_MIN * NSEC_PER_USEC) {
pr_err("Invalid pwm handle or parameters\n");
return -EINVAL;
}
spin_lock_irqsave(&chip->lpg_lock, flags);
if (pwm->period != period_us) {
qpnp_lpg_calc_period(period_us, chip);
if (pwm->period != period_ns) {
qpnp_lpg_calc_period(LVL_NSEC, period_ns, chip);
qpnp_lpg_save_period(chip);
pwm->period = period_us;
pwm->period = period_ns;
chip->pwm_config.pwm_period = period_ns / NSEC_PER_USEC;
}
rc = _pwm_config(chip, duty_us, period_us);
rc = _pwm_config(chip, LVL_NSEC, duty_ns, period_ns);
spin_unlock_irqrestore(&chip->lpg_lock, flags);
@ -1242,7 +1257,7 @@ int qpnp_pwm_config(struct pwm_chip *pwm_chip,
* @pwm_chip: the PWM chip
* @pwm: the PWM device
*/
int qpnp_pwm_enable(struct pwm_chip *pwm_chip,
static int qpnp_pwm_enable(struct pwm_chip *pwm_chip,
struct pwm_device *pwm)
{
int rc;
@ -1259,7 +1274,7 @@ int qpnp_pwm_enable(struct pwm_chip *pwm_chip,
* @pwm_chip: the PWM chip
* @pwm: the PWM device
*/
void qpnp_pwm_disable(struct pwm_chip *pwm_chip,
static void qpnp_pwm_disable(struct pwm_chip *pwm_chip,
struct pwm_device *pwm)
{
@ -1435,6 +1450,51 @@ out_unlock:
}
EXPORT_SYMBOL_GPL(pwm_config_pwm_value);
/**
* pwm_config_us - change a PWM device configuration
* @pwm: the PWM device
* @period_us: period in microseconds
* @duty_us: duty cycle in microseconds
*/
int pwm_config_us(struct pwm_device *pwm, int duty_us, int period_us)
{
int rc;
unsigned long flags;
struct qpnp_pwm_chip *chip;
if (pwm == NULL || IS_ERR(pwm) ||
duty_us > period_us ||
(unsigned)period_us > PM_PWM_PERIOD_MAX ||
(unsigned)period_us < PM_PWM_PERIOD_MIN) {
pr_err("Invalid pwm handle or parameters\n");
return -EINVAL;
}
chip = qpnp_pwm_from_pwm_dev(pwm);
spin_lock_irqsave(&chip->lpg_lock, flags);
if (chip->pwm_config.pwm_period != period_us) {
qpnp_lpg_calc_period(LVL_USEC, period_us, chip);
qpnp_lpg_save_period(chip);
chip->pwm_config.pwm_period = period_us;
if ((unsigned)period_us > (unsigned)(-1) / NSEC_PER_USEC)
pwm->period = 0;
else
pwm->period = (unsigned)period_us * NSEC_PER_USEC;
}
rc = _pwm_config(chip, LVL_USEC, duty_us, period_us);
spin_unlock_irqrestore(&chip->lpg_lock, flags);
if (rc)
pr_err("Failed to configure PWM mode\n");
return rc;
}
EXPORT_SYMBOL(pwm_config_us);
/**
* pwm_lut_config - change LPG LUT device configuration
* @pwm: the PWM device
@ -1483,10 +1543,10 @@ int pwm_lut_config(struct pwm_device *pwm, int period_us,
spin_lock_irqsave(&chip->lpg_lock, flags);
if (pwm->period != period_us) {
qpnp_lpg_calc_period(period_us, chip);
if (chip->pwm_config.pwm_period != period_us) {
qpnp_lpg_calc_period(LVL_USEC, period_us, chip);
qpnp_lpg_save_period(chip);
pwm->period = period_us;
chip->pwm_config.pwm_period = period_us;
}
rc = _pwm_lut_config(chip, period_us, duty_pct, lut_params);
@ -1518,7 +1578,7 @@ static int qpnp_parse_pwm_dt_config(struct device_node *of_pwm_node,
return rc;
}
rc = _pwm_config(chip, chip->pwm_config.pwm_duty, period);
rc = _pwm_config(chip, LVL_USEC, chip->pwm_config.pwm_duty, period);
return rc;
}

12
include/linux/qpnp/pwm.h
View File

@ -1,4 +1,4 @@
/* Copyright (c) 2012, The Linux Foundation. All rights reserved.
/* Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
@ -146,6 +146,12 @@ struct lut_params {
int pwm_lut_config(struct pwm_device *pwm, int period_us,
int duty_pct[], struct lut_params lut_params);
/*
* support microsecond level configuration
*/
int pwm_config_us(struct pwm_device *pwm,
int duty_us, int period_us);
/* Standard APIs supported */
/*
* pwm_request - request a PWM device
@ -161,8 +167,8 @@ int pwm_lut_config(struct pwm_device *pwm, int period_us,
/*
* pwm_config - change a PWM device configuration
* @pwm: the PWM device
* @period_us: period in microsecond
* @duty_us: duty cycle in microsecond
* @period_ns: period in nanosecond
* @duty_ns: duty cycle in nanosecond
*/
/*