[PATCH v2 2/3] pwm: jz4740: Obtain regmap from parent node

Paul Cercueil
2019-11-16T17:42:43Z

The TCU registers are shared between a handful of drivers, accessing
them through the same regmap.

While this driver is devicetree-compatible, it is never (as of now)
probed from devicetree, so this change does not introduce a ABI problem
with current devicetree files.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
---

Notes:
v2: This patch is now after the patch introducing TCU clocks, so the code
changed a bit.

drivers/pwm/Kconfig | 1 +
drivers/pwm/pwm-jz4740.c | 70 ++++++++++++++++++++++++++--------------
2 files changed, 46 insertions(+), 25 deletions(-)

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index e998e5cb01b0..b6cbfb97e85f 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -226,6 +226,7 @@ config PWM_JZ4740
tristate "Ingenic JZ47xx PWM support"
depends on MACH_INGENIC
depends on COMMON_CLK
+ select MFD_SYSCON
help
Generic PWM framework driver for Ingenic JZ47xx based
machines.
diff --git a/drivers/pwm/pwm-jz4740.c b/drivers/pwm/pwm-jz4740.c
index fd83644f9323..a5368b98652d 100644
--- a/drivers/pwm/pwm-jz4740.c
+++ b/drivers/pwm/pwm-jz4740.c
@@ -13,17 +13,19 @@
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/kernel.h>
+#include <linux/mfd/ingenic-tcu.h>
+#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
-
-#include <asm/mach-jz4740/timer.h>
+#include <linux/regmap.h>

#define NUM_PWM 8

struct jz4740_pwm_chip {
struct pwm_chip chip;
+ struct regmap *map;
};

static inline struct jz4740_pwm_chip *to_jz4740(struct pwm_chip *chip)
@@ -64,9 +66,10 @@ static int jz4740_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)

static void jz4740_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
{
+ struct jz4740_pwm_chip *jz = to_jz4740(chip);
struct clk *clk = pwm_get_chip_data(pwm);

- jz4740_timer_set_ctrl(pwm->hwpwm, 0);
+ regmap_write(jz->map, TCU_REG_TCSRc(pwm->hwpwm), 0);

clk_disable_unprepare(clk);
clk_put(clk);
@@ -74,36 +77,39 @@ static void jz4740_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)

static int jz4740_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
- uint32_t ctrl = jz4740_timer_get_ctrl(pwm->pwm);
+ struct jz4740_pwm_chip *jz = to_jz4740(chip);

- ctrl |= JZ_TIMER_CTRL_PWM_ENABLE;
- jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
- jz4740_timer_enable(pwm->hwpwm);
+ /* Enable PWM output */
+ regmap_update_bits(jz->map, TCU_REG_TCSRc(pwm->hwpwm),
+ TCU_TCSR_PWM_EN, TCU_TCSR_PWM_EN);
+
+ /* Start counter */
+ regmap_write(jz->map, TCU_REG_TESR, BIT(pwm->hwpwm));

return 0;
}

static void jz4740_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
- uint32_t ctrl = jz4740_timer_get_ctrl(pwm->hwpwm);
+ struct jz4740_pwm_chip *jz = to_jz4740(chip);

/*
* Set duty > period. This trick allows the TCU channels in TCU2 mode to
* properly return to their init level.
*/
- jz4740_timer_set_duty(pwm->hwpwm, 0xffff);
- jz4740_timer_set_period(pwm->hwpwm, 0x0);
+ regmap_write(jz->map, TCU_REG_TDHRc(pwm->hwpwm), 0xffff);
+ regmap_write(jz->map, TCU_REG_TDFRc(pwm->hwpwm), 0x0);

/*
* Disable PWM output.
* In TCU2 mode (channel 1/2 on JZ4750+), this must be done before the
* counter is stopped, while in TCU1 mode the order does not matter.
*/
- ctrl &= ~JZ_TIMER_CTRL_PWM_ENABLE;
- jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
+ regmap_update_bits(jz->map, TCU_REG_TCSRc(pwm->hwpwm),
+ TCU_TCSR_PWM_EN, 0);

/* Stop counter */
- jz4740_timer_disable(pwm->hwpwm);
+ regmap_write(jz->map, TCU_REG_TECR, BIT(pwm->hwpwm));
}

static int jz4740_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
@@ -115,7 +121,6 @@ static int jz4740_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
unsigned long rate, period, duty;
unsigned long long tmp;
unsigned int prescaler = 0;
- uint16_t ctrl;

rate = clk_get_rate(parent_clk);
tmp = (unsigned long long)rate * state->period;
@@ -142,24 +147,32 @@ static int jz4740_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,

clk_set_rate(clk, rate);

- jz4740_timer_set_count(pwm->hwpwm, 0);
- jz4740_timer_set_duty(pwm->hwpwm, duty);
- jz4740_timer_set_period(pwm->hwpwm, period);
+ /* Reset counter to 0 */
+ regmap_write(jz4740->map, TCU_REG_TCNTc(pwm->hwpwm), 0);
+
+ /* Set duty */
+ regmap_write(jz4740->map, TCU_REG_TDHRc(pwm->hwpwm), duty);

- ctrl = jz4740_timer_get_ctrl(pwm->hwpwm);
- ctrl |= JZ_TIMER_CTRL_PWM_ABBRUPT_SHUTDOWN;
+ /* Set period */
+ regmap_write(jz4740->map, TCU_REG_TDFRc(pwm->hwpwm), period);

+ /* Set abrupt shutdown */
+ regmap_update_bits(jz4740->map, TCU_REG_TCSRc(pwm->hwpwm),
+ TCU_TCSR_PWM_SD, TCU_TCSR_PWM_SD);
+
+ /* Set polarity */
switch (state->polarity) {
case PWM_POLARITY_NORMAL:
- ctrl &= ~JZ_TIMER_CTRL_PWM_ACTIVE_LOW;
+ regmap_update_bits(jz4740->map, TCU_REG_TCSRc(pwm->hwpwm),
+ TCU_TCSR_PWM_INITL_HIGH, 0);
break;
case PWM_POLARITY_INVERSED:
- ctrl |= JZ_TIMER_CTRL_PWM_ACTIVE_LOW;
+ regmap_update_bits(jz4740->map, TCU_REG_TCSRc(pwm->hwpwm),
+ TCU_TCSR_PWM_INITL_HIGH,
+ TCU_TCSR_PWM_INITL_HIGH);
break;
}

- jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
-
if (state->enabled)
jz4740_pwm_enable(chip, pwm);

@@ -176,12 +189,19 @@ static const struct pwm_ops jz4740_pwm_ops = {
static int jz4740_pwm_probe(struct platform_device *pdev)
{
struct jz4740_pwm_chip *jz4740;
+ struct device *dev = &pdev->dev;

- jz4740 = devm_kzalloc(&pdev->dev, sizeof(*jz4740), GFP_KERNEL);
+ jz4740 = devm_kzalloc(dev, sizeof(*jz4740), GFP_KERNEL);
if (!jz4740)
return -ENOMEM;

- jz4740->chip.dev = &pdev->dev;
+ jz4740->map = device_node_to_regmap(dev->parent->of_node);
+ if (!jz4740->map) {
+ dev_err(dev, "regmap not found\n");
+ return -EINVAL;
+ }
+
+ jz4740->chip.dev = dev;
jz4740->chip.ops = &jz4740_pwm_ops;
jz4740->chip.npwm = NUM_PWM;
jz4740->chip.base = -1;
--
2.24.0