Re: [PATCH v4 2/2] pinctrl: qcom: Add sm8250 lpass lpi pinctrl driver

[Srinivas Kandagatla <srinivas.kandagatla@linaro.org>]

Many thanks for review Bjorn,


On 01/12/2020 00:47, Bjorn Andersson wrote:
> On Mon 16 Nov 08:34 CST 2020, Srinivas Kandagatla wrote:
> 
>> Add initial pinctrl driver to support pin configuration for
>> LPASS (Low Power Audio SubSystem) LPI (Low Power Island) pinctrl
>> on SM8250.
>>
>> This IP is an additional pin control block for Audio Pins on top the
>> existing SoC Top level pin-controller.
>> Hardware setup looks like:
>>
>> TLMM GPIO[146 - 159] --> LPASS LPI GPIO [0 - 13]
>>
> 
> Iiuc the LPI TLMM block is just "another pinmux/pinconf block" found in
> these SoCs, with the additional magic that the 14 pads are muxed with
> some of the TLMM pins - to allow the system integrator to choose how
> many pins the LPI should have access to.
> 
> I also believe this is what the "egpio" bit in the TLMM registers are
> used for (i.e. egpio = route to LPI, egpio = 1 route to TLMM), so we
> should need to add support for toggling this bit in the TLMM as well
> (which I think we should do as a pinconf in the pinctrl-msm).

Yes, we should add egpio function to these pins in main TLMM pinctrl!

> 
>> This pin controller has some similarities compared to Top level
>> msm SoC Pin controller like 'each pin belongs to a single group'
>> and so on. However this one is intended to control only audio
>> pins in particular, which can not be configured/touched by the
>> Top level SoC pin controller except setting them as gpios.
> 
> Seems like this is just a property of what functions they routed in this
> region of the TLMM - and when egpio = 1 it could have been anything
> else.
> 
>> Apart from this, slew rate is also available in this block for
>> certain pins which are connected to SLIMbus or SoundWire Bus.
>>
>> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
>> ---
>>   drivers/pinctrl/qcom/Kconfig             |   8 +
>>   drivers/pinctrl/qcom/Makefile            |   1 +
>>   drivers/pinctrl/qcom/pinctrl-lpass-lpi.c | 734 +++++++++++++++++++++++
>>   3 files changed, 743 insertions(+)
>>   create mode 100644 drivers/pinctrl/qcom/pinctrl-lpass-lpi.c
>>
>> diff --git a/drivers/pinctrl/qcom/Kconfig b/drivers/pinctrl/qcom/Kconfig
>> index 5fe7b8aaf69d..d3e4e89c2810 100644
>> --- a/drivers/pinctrl/qcom/Kconfig
>> +++ b/drivers/pinctrl/qcom/Kconfig
>> @@ -236,4 +236,12 @@ config PINCTRL_SM8250
>>   	  Qualcomm Technologies Inc TLMM block found on the Qualcomm
>>   	  Technologies Inc SM8250 platform.
>>   
>> +config PINCTRL_LPASS_LPI
>> +	tristate "Qualcomm Technologies Inc LPASS LPI pin controller driver"
>> +	depends on GPIOLIB
>> +	help
>> +	  This is the pinctrl, pinmux, pinconf and gpiolib driver for the
>> +	  Qualcomm Technologies Inc LPASS (Low Power Audio SubSystem) LPI
>> +	  (Low Power Island) found on the Qualcomm Technologies Inc SoCs.
>> +
>>   endif
>> diff --git a/drivers/pinctrl/qcom/Makefile b/drivers/pinctrl/qcom/Makefile
>> index 9e3d9c91a444..c8520155fb1b 100644
>> --- a/drivers/pinctrl/qcom/Makefile
>> +++ b/drivers/pinctrl/qcom/Makefile
>> @@ -28,3 +28,4 @@ obj-$(CONFIG_PINCTRL_SDM660)   += pinctrl-sdm660.o
>>   obj-$(CONFIG_PINCTRL_SDM845) += pinctrl-sdm845.o
>>   obj-$(CONFIG_PINCTRL_SM8150) += pinctrl-sm8150.o
>>   obj-$(CONFIG_PINCTRL_SM8250) += pinctrl-sm8250.o
>> +obj-$(CONFIG_PINCTRL_LPASS_LPI) += pinctrl-lpass-lpi.o
>> diff --git a/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c b/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c
>> new file mode 100644
>> index 000000000000..63cfbb2d032a
>> --- /dev/null
>> +++ b/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c
>> @@ -0,0 +1,734 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (c) 2016-2019, The Linux Foundation. All rights reserved.
>> + * Copyright (c) 2020 Linaro Ltd.
>> + */
>> +
>> +#include <linux/bitops.h>
>> +#include <linux/clk.h>
>> +#include <linux/gpio/driver.h>
>> +#include <linux/io.h>
>> +#include <linux/module.h>
>> +#include <linux/of_device.h>
>> +#include <linux/of.h>
>> +#include <linux/pinctrl/pinconf-generic.h>
>> +#include <linux/pinctrl/pinconf.h>
>> +#include <linux/pinctrl/pinmux.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/slab.h>
>> +#include <linux/types.h>
>> +#include "../core.h"
>> +#include "../pinctrl-utils.h"
>> +
>> +#define LPI_GPIO_REG_VAL_CTL             0x00
> 
> I think LPI_GPIO_CFG_REG would be a better name for this.
> 
>> +#define LPI_GPIO_REG_DIR_CTL             0x04
> 
> Afaict, BIT(9) of LPI_GPIO_CFG_REG controls of the if the pin should be
> output or not. This register provides the read value as BIT(0) and the
> output value in BIT(1).
> 
> So this would rather be the LPI_GPIO_VALUE_REG.

Yes, that is true, will change it accordingly!

> 
>> +#define LPI_SLEW_REG_VAL_CTL             0x00
>> +#define LPI_SLEW_RATE_MAX                0x03
>> +#define LPI_SLEW_BITS_SIZE               0x02
>> +#define LPI_GPIO_REG_PULL_SHIFT		0x0
>> +#define LPI_GPIO_REG_PULL_MASK		GENMASK(1, 0)
>> +#define LPI_GPIO_REG_FUNCTION_SHIFT	0x2
>> +#define LPI_GPIO_REG_FUNCTION_MASK	GENMASK(5, 2)
>> +#define LPI_GPIO_REG_OUT_STRENGTH_SHIFT	0x6
>> +#define LPI_GPIO_REG_OUT_STRENGTH_MASK	GENMASK(8, 6)
>> +#define LPI_GPIO_REG_OE_SHIFT		0x9
>> +#define LPI_GPIO_REG_OE_MASK		BIT(9)
>> +#define LPI_GPIO_REG_DIR_SHIFT		0x1
>> +#define LPI_GPIO_REG_DIR_MASK		0x2
>> +#define LPI_GPIO_BIAS_DISABLE		0x0
>> +#define LPI_GPIO_PULL_DOWN		0x1
>> +#define LPI_GPIO_KEEPER			0x2
>> +#define LPI_GPIO_PULL_UP		0x3
>> +#define LPI_GPIO_DS_TO_VAL(v) ((v / 2 - 1) << LPI_GPIO_REG_OUT_STRENGTH_SHIFT)
>> +#define NO_SLEW				-1
>> +
>> +#define LPI_FUNCTION(fname)			                \
>> +	[LPI_MUX_##fname] = {		                \
>> +		.name = #fname,				\
>> +		.groups = fname##_groups,               \
>> +		.ngroups = ARRAY_SIZE(fname##_groups),	\
>> +	}
>> +
>> +#define LPI_PINGROUP(id, soff, f1, f2, f3, f4)		\
>> +	{						\
>> +		.name = "gpio" #id,			\
>> +		.pins = gpio##id##_pins,		\
>> +		.pin = id,				\
>> +		.slew_offset = soff,			\
>> +		.npins = ARRAY_SIZE(gpio##id##_pins),	\
>> +		.funcs = (int[]){			\
>> +			LPI_MUX_gpio,			\
>> +			LPI_MUX_##f1,			\
>> +			LPI_MUX_##f2,			\
>> +			LPI_MUX_##f3,			\
>> +			LPI_MUX_##f4,			\
>> +		},					\
>> +		.nfuncs = 5,				\
>> +	}
>> +
>> +struct lpi_pingroup {
>> +	const char *name;
>> +	const unsigned int *pins;
>> +	unsigned int npins;
>> +	unsigned int pin;
>> +	/* Bit offset in slew register for SoundWire pins only */
>> +	unsigned int slew_offset;
>> +	unsigned int *funcs;
>> +	unsigned int nfuncs;
>> +};
>> +
>> +struct lpi_function {
>> +	const char *name;
>> +	const char * const *groups;
>> +	unsigned int ngroups;
>> +};
>> +
>> +struct lpi_pinctrl_variant_data {
>> +	int tlmm_reg_offset;
>> +	const struct pinctrl_pin_desc *pins;
>> +	int npins;
>> +	const struct lpi_pingroup *groups;
>> +	int ngroups;
>> +	const struct lpi_function *functions;
>> +	int nfunctions;
>> +};
>> +
>> +#define MAX_LPI_NUM_CLKS	2
>> +
>> +struct lpi_pinctrl {
>> +	struct device *dev;
>> +	struct pinctrl_dev *ctrl;
>> +	struct gpio_chip chip;
>> +	struct pinctrl_desc desc;
>> +	char __iomem *tlmm_base;
>> +	char __iomem *slew_base;
>> +	struct clk_bulk_data clks[MAX_LPI_NUM_CLKS];
>> +	struct mutex slew_access_lock;
>> +	const struct lpi_pinctrl_variant_data *data;
>> +};
>> +
>> +/* sm8250 variant specific data */
>> +static const struct pinctrl_pin_desc sm8250_lpi_pins[] = {
>> +	PINCTRL_PIN(0, "gpio0"),
>> +	PINCTRL_PIN(1, "gpio1"),
>> +	PINCTRL_PIN(2, "gpio2"),
>> +	PINCTRL_PIN(3, "gpio3"),
>> +	PINCTRL_PIN(4, "gpio4"),
>> +	PINCTRL_PIN(5, "gpio5"),
>> +	PINCTRL_PIN(6, "gpio6"),
>> +	PINCTRL_PIN(7, "gpio7"),
>> +	PINCTRL_PIN(8, "gpio8"),
>> +	PINCTRL_PIN(9, "gpio9"),
>> +	PINCTRL_PIN(10, "gpio10"),
>> +	PINCTRL_PIN(11, "gpio11"),
>> +	PINCTRL_PIN(12, "gpio12"),
>> +	PINCTRL_PIN(13, "gpio13"),
>> +};
>> +
>> +enum sm8250_lpi_functions {
>> +	LPI_MUX_swr_tx_clk,
> 
> Please sort these.
> 
>> +	LPI_MUX_qua_mi2s_sclk,
>> +	LPI_MUX_swr_tx_data1,
> 
> As there's no single pin that can be both data1 and data2 I think you
> should have a single group for swr_tx_data and use this function for
> both swr_tx_data pins. Or perhaps even just have one for swr or swr_tx.
> 
> (This is nice when you're writing DT later on)

I did think about this, but we have a rx_data2 pin in different function 
compared to other rx data pins.

The reason to keep it as it is :
1> as this will bring in an additional complexity to the code
2> we have these represented exactly as what hw data sheet mentions it!

> 
>> +	LPI_MUX_qua_mi2s_ws,
>> +	LPI_MUX_swr_tx_data2,
>> +	LPI_MUX_qua_mi2s_data0,
>> +	LPI_MUX_swr_rx_clk,
>> +	LPI_MUX_qua_mi2s_data1,
>> +	LPI_MUX_swr_rx_data1,
>> +	LPI_MUX_qua_mi2s_data2,
>> +	LPI_MUX_swr_tx_data3,
>> +	LPI_MUX_swr_rx_data2,
>> +	LPI_MUX_dmic1_clk,
>> +	LPI_MUX_i2s1_clk,
>> +	LPI_MUX_dmic1_data,
>> +	LPI_MUX_i2s1_ws,
>> +	LPI_MUX_dmic2_clk,
>> +	LPI_MUX_i2s1_data0,
>> +	LPI_MUX_dmic2_data,
>> +	LPI_MUX_i2s1_data1,
>> +	LPI_MUX_i2s2_clk,
>> +	LPI_MUX_wsa_swr_clk,
>> +	LPI_MUX_i2s2_ws,
>> +	LPI_MUX_wsa_swr_data,
>> +	LPI_MUX_dmic3_clk,
>> +	LPI_MUX_i2s2_data0,
>> +	LPI_MUX_dmic3_data,
>> +	LPI_MUX_i2s2_data1,
>> +	LPI_MUX_gpio,
>> +	LPI_MUX_NA,
> 
> For me replacing "NA" with "_" makes the lpi_pingroup table below easier
> to read (i.e. this becomes LPI_MUX__).
> 
Okay sure, will do that!

>> +};
>> +
>> +static const unsigned int gpio0_pins[] = { 0 };
>> +static const unsigned int gpio1_pins[] = { 1 };
>> +static const unsigned int gpio2_pins[] = { 2 };
>> +static const unsigned int gpio3_pins[] = { 3 };
>> +static const unsigned int gpio4_pins[] = { 4 };
>> +static const unsigned int gpio5_pins[] = { 5 };
>> +static const unsigned int gpio6_pins[] = { 6 };
>> +static const unsigned int gpio7_pins[] = { 7 };
>> +static const unsigned int gpio8_pins[] = { 8 };
>> +static const unsigned int gpio9_pins[] = { 9 };
>> +static const unsigned int gpio10_pins[] = { 10 };
>> +static const unsigned int gpio11_pins[] = { 11 };
>> +static const unsigned int gpio12_pins[] = { 12 };
>> +static const unsigned int gpio13_pins[] = { 13 };
>> +static const char * const swr_tx_clk_groups[] = { "gpio0" };
>> +static const char * const swr_tx_data1_groups[] = { "gpio1" };
>> +static const char * const swr_tx_data2_groups[] = { "gpio2" };
>> +static const char * const swr_rx_clk_groups[] = { "gpio3" };
>> +static const char * const swr_rx_data1_groups[] = { "gpio4" };
>> +static const char * const swr_tx_data3_groups[] = { "gpio5" };
>> +static const char * const dmic1_clk_groups[] = { "gpio6" };
>> +static const char * const dmic1_data_groups[] = { "gpio7" };
>> +static const char * const dmic2_clk_groups[] = { "gpio8" };
>> +static const char * const dmic2_data_groups[] = { "gpio9" };
>> +static const char * const i2s2_clk_groups[] = { "gpio10" };
>> +static const char * const i2s2_ws_groups[] = { "gpio11" };
>> +static const char * const dmic3_clk_groups[] = { "gpio12" };
>> +static const char * const dmic3_data_groups[] = { "gpio13" };
>> +static const char * const qua_mi2s_sclk_groups[] = { "gpio0" };
>> +static const char * const qua_mi2s_ws_groups[] = { "gpio1" };
>> +static const char * const qua_mi2s_data0_groups[] = { "gpio2" };
>> +static const char * const qua_mi2s_data1_groups[] = { "gpio3" };
>> +static const char * const qua_mi2s_data2_groups[] = { "gpio4" };
>> +static const char * const swr_rx_data2_groups[] = { "gpio5" };
>> +static const char * const i2s1_clk_groups[] = { "gpio6" };
>> +static const char * const i2s1_ws_groups[] = { "gpio7" };
>> +static const char * const i2s1_data0_groups[] = { "gpio8" };
>> +static const char * const i2s1_data1_groups[] = { "gpio9" };
>> +static const char * const wsa_swr_clk_groups[] = { "gpio10" };
>> +static const char * const wsa_swr_data_groups[] = { "gpio11" };
>> +static const char * const i2s2_data0_groups[] = { "gpio12" };
>> +static const char * const i2s2_data1_groups[] = { "gpio13" };
>> +
>> +static const struct lpi_pingroup sm8250_groups[] = {
>> +	LPI_PINGROUP(0, 0, swr_tx_clk, qua_mi2s_sclk, NA, NA),
>> +	LPI_PINGROUP(1, 2, swr_tx_data1, qua_mi2s_ws, NA, NA),
>> +	LPI_PINGROUP(2, 4, swr_tx_data2, qua_mi2s_data0, NA, NA),
>> +	LPI_PINGROUP(3, 8, swr_rx_clk, qua_mi2s_data1, NA, NA),
>> +	LPI_PINGROUP(4, 10, swr_rx_data1, qua_mi2s_data2, NA, NA),
>> +	LPI_PINGROUP(5, 12, swr_tx_data3, swr_rx_data2, NA, NA),
>> +	LPI_PINGROUP(6, NO_SLEW, dmic1_clk, i2s1_clk, NA,  NA),
>> +	LPI_PINGROUP(7, NO_SLEW, dmic1_data, i2s1_ws, NA, NA),
>> +	LPI_PINGROUP(8, NO_SLEW, dmic2_clk, i2s1_data0, NA, NA),
>> +	LPI_PINGROUP(9, NO_SLEW, dmic2_data, i2s1_data1, NA, NA),
>> +	LPI_PINGROUP(10, 16, i2s2_clk, wsa_swr_clk, NA, NA),
>> +	LPI_PINGROUP(11, 18, i2s2_ws, wsa_swr_data, NA, NA),
>> +	LPI_PINGROUP(12, NO_SLEW, dmic3_clk, i2s2_data0, NA, NA),
>> +	LPI_PINGROUP(13, NO_SLEW, dmic3_data, i2s2_data1, NA, NA),
>> +};
>> +
>> +static const struct lpi_function sm8250_functions[] = {
>> +	LPI_FUNCTION(swr_tx_clk),
> 
> Please sort these.
> 
>> +	LPI_FUNCTION(qua_mi2s_sclk),
>> +	LPI_FUNCTION(swr_tx_data1),
>> +	LPI_FUNCTION(qua_mi2s_ws),
>> +	LPI_FUNCTION(swr_tx_data2),
>> +	LPI_FUNCTION(qua_mi2s_data0),
>> +	LPI_FUNCTION(swr_rx_clk),
>> +	LPI_FUNCTION(qua_mi2s_data1),
>> +	LPI_FUNCTION(swr_rx_data1),
>> +	LPI_FUNCTION(qua_mi2s_data2),
>> +	LPI_FUNCTION(swr_tx_data3),
>> +	LPI_FUNCTION(swr_rx_data2),
>> +	LPI_FUNCTION(dmic1_clk),
>> +	LPI_FUNCTION(i2s1_clk),
>> +	LPI_FUNCTION(dmic1_data),
>> +	LPI_FUNCTION(i2s1_ws),
>> +	LPI_FUNCTION(dmic2_clk),
>> +	LPI_FUNCTION(i2s1_data0),
>> +	LPI_FUNCTION(dmic2_data),
>> +	LPI_FUNCTION(i2s1_data1),
>> +	LPI_FUNCTION(i2s2_clk),
>> +	LPI_FUNCTION(wsa_swr_clk),
>> +	LPI_FUNCTION(i2s2_ws),
>> +	LPI_FUNCTION(wsa_swr_data),
>> +	LPI_FUNCTION(dmic3_clk),
>> +	LPI_FUNCTION(i2s2_data0),
>> +	LPI_FUNCTION(dmic3_data),
>> +	LPI_FUNCTION(i2s2_data1),
>> +};
>> +
>> +static struct lpi_pinctrl_variant_data sm8250_lpi_data = {
>> +	.tlmm_reg_offset = 0x1000,
> 
> Do we have any platform in sight where this is not 0x1000? Could we just
> make a define out of it?
Am not 100% sure ATM, But I wanted to keep this flexible as these 
offsets in downstream were part of device tree for some reason, so 
having offset here for particular compatible made more sense for me!

> 
>> +	.pins = sm8250_lpi_pins,
>> +	.npins = ARRAY_SIZE(sm8250_lpi_pins),
>> +	.groups = sm8250_groups,
>> +	.ngroups = ARRAY_SIZE(sm8250_groups),
>> +	.functions = sm8250_functions,
>> +	.nfunctions = ARRAY_SIZE(sm8250_functions),
>> +};
>> +
>> +static int lpi_gpio_read(struct lpi_pinctrl *state, unsigned int pin,
>> +			 unsigned int addr)
>> +{
>> +	return ioread32(state->tlmm_base +
>> +			state->data->tlmm_reg_offset * pin + addr);
>> +}
>> +
>> +static int lpi_gpio_write(struct lpi_pinctrl *state, unsigned int pin,
>> +			  unsigned int addr, unsigned int val)
>> +{
>> +	iowrite32(val, state->tlmm_base +
>> +		  state->data->tlmm_reg_offset * pin + addr);
>> +
>> +	return 0;
>> +}
>> +
>> +static int lpi_gpio_get_groups_count(struct pinctrl_dev *pctldev)
>> +{
>> +	struct lpi_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
>> +
>> +	return pctrl->data->ngroups;
>> +}
>> +
>> +static const char *lpi_gpio_get_group_name(struct pinctrl_dev *pctldev,
>> +					   unsigned int group)
>> +{
>> +	struct lpi_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
>> +
>> +	return pctrl->data->groups[group].name;
>> +}
>> +
>> +static int lpi_gpio_get_group_pins(struct pinctrl_dev *pctldev,
>> +				   unsigned int group,
>> +				   const unsigned int **pins,
>> +				   unsigned int *num_pins)
>> +{
>> +	struct lpi_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
>> +
>> +	*pins = pctrl->data->groups[group].pins;
>> +	*num_pins = pctrl->data->groups[group].npins;
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct pinctrl_ops lpi_gpio_pinctrl_ops = {
>> +	.get_groups_count	= lpi_gpio_get_groups_count,
>> +	.get_group_name		= lpi_gpio_get_group_name,
>> +	.get_group_pins		= lpi_gpio_get_group_pins,
>> +	.dt_node_to_map		= pinconf_generic_dt_node_to_map_group,
>> +	.dt_free_map		= pinctrl_utils_free_map,
>> +};
>> +
>> +static int lpi_gpio_get_functions_count(struct pinctrl_dev *pctldev)
>> +{
>> +	struct lpi_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
>> +
>> +	return pctrl->data->nfunctions;
>> +}
>> +
>> +static const char *lpi_gpio_get_function_name(struct pinctrl_dev *pctldev,
>> +					      unsigned int function)
>> +{
>> +	struct lpi_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
>> +
>> +	return pctrl->data->functions[function].name;
>> +}
>> +
>> +static int lpi_gpio_get_function_groups(struct pinctrl_dev *pctldev,
>> +					unsigned int function,
>> +					const char *const **groups,
>> +					unsigned *const num_qgroups)
>> +{
>> +	struct lpi_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
>> +
>> +	*groups = pctrl->data->functions[function].groups;
>> +	*num_qgroups = pctrl->data->functions[function].ngroups;
>> +
>> +	return 0;
>> +}
>> +
>> +static int lpi_gpio_set_mux(struct pinctrl_dev *pctldev, unsigned int function,
>> +			    unsigned int group_num)
>> +{
>> +	struct lpi_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
>> +	const struct lpi_pingroup *g = &pctrl->data->groups[group_num];
>> +	unsigned int val;
>> +	int i, pin = g->pin;
>> +
>> +	for (i = 0; i < g->nfuncs; i++) {
>> +		if (g->funcs[i] == function)
>> +			break;
>> +	}
>> +
>> +	if (WARN_ON(i == g->nfuncs))
>> +		return -EINVAL;
>> +
>> +	val = lpi_gpio_read(pctrl, pin, LPI_GPIO_REG_VAL_CTL);
>> +	val &= ~LPI_GPIO_REG_FUNCTION_MASK;
>> +	val |= i << LPI_GPIO_REG_FUNCTION_SHIFT;
> 
> I think this would benefit from FIELD_SET()
I can give that a go!

> 
>> +	lpi_gpio_write(pctrl, pin, LPI_GPIO_REG_VAL_CTL, val);
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct pinmux_ops lpi_gpio_pinmux_ops = {
>> +	.get_functions_count	= lpi_gpio_get_functions_count,
>> +	.get_function_name	= lpi_gpio_get_function_name,
>> +	.get_function_groups	= lpi_gpio_get_function_groups,
>> +	.set_mux		= lpi_gpio_set_mux,
>> +};
>> +
>> +static int lpi_config_get(struct pinctrl_dev *pctldev,
>> +			  unsigned int pin, unsigned long *config)
>> +{
>> +	unsigned int param = pinconf_to_config_param(*config);
>> +	struct lpi_pinctrl *state = dev_get_drvdata(pctldev->dev);
>> +	unsigned int arg = 0;
>> +	int is_out;
>> +	int pull;
>> +	u32 ctl_reg;
>> +
>> +	ctl_reg = lpi_gpio_read(state, pin, LPI_GPIO_REG_DIR_CTL);
>> +
>> +	is_out = (ctl_reg & LPI_GPIO_REG_DIR_MASK) >> LPI_GPIO_REG_DIR_SHIFT;
> 
> This is a single bit, which would be clarified if you replaced _MASK and
> _SHIFT with a single LPI_GPIO_OUT BIT(1)

yep!

> 
>> +
>> +	ctl_reg = lpi_gpio_read(state, pin, LPI_GPIO_REG_VAL_CTL);
>> +
>> +	pull = (ctl_reg & LPI_GPIO_REG_PULL_MASK) >> LPI_GPIO_REG_PULL_SHIFT;
>> +
>> +	switch (param) {
>> +	case PIN_CONFIG_BIAS_DISABLE:
>> +		if (pull == LPI_GPIO_BIAS_DISABLE)
>> +			arg = 1;
>> +		break;
>> +	case PIN_CONFIG_BIAS_PULL_DOWN:
>> +		if (pull == LPI_GPIO_PULL_DOWN)
>> +			arg = 1;
>> +		break;
>> +	case PIN_CONFIG_BIAS_BUS_HOLD:
>> +		if (pull == LPI_GPIO_KEEPER)
>> +			arg = 1;
>> +		break;
>> +	case PIN_CONFIG_BIAS_PULL_UP:
>> +		if (pull == LPI_GPIO_PULL_UP)
>> +			arg = 1;
>> +		break;
>> +	case PIN_CONFIG_INPUT_ENABLE:
>> +	case PIN_CONFIG_OUTPUT:
>> +		if (is_out)
>> +			arg = 1;
>> +		break;
>> +	default:
>> +		return -EINVAL;
>> +	}
>> +
>> +	*config = pinconf_to_config_packed(param, arg);
>> +	return 0;
>> +}
>> +
>> +static int lpi_config_set(struct pinctrl_dev *pctldev, unsigned int group,
>> +			  unsigned long *configs, unsigned int nconfs)
>> +{
>> +	struct lpi_pinctrl *pctrl = dev_get_drvdata(pctldev->dev);
>> +	unsigned int param, arg, pullup, strength;
>> +	const struct lpi_pingroup *g;
>> +	bool value, output_enabled = false;
>> +	unsigned long val;
>> +	int i, slew_offset, ret = 0;
>> +
>> +	g = &pctrl->data->groups[group];
>> +	for (i = 0; i < nconfs; i++) {
>> +		param = pinconf_to_config_param(configs[i]);
>> +		arg = pinconf_to_config_argument(configs[i]);
>> +
>> +		switch (param) {
>> +		case PIN_CONFIG_BIAS_DISABLE:
>> +			pullup = LPI_GPIO_BIAS_DISABLE;
>> +			break;
>> +		case PIN_CONFIG_BIAS_PULL_DOWN:
>> +			pullup = LPI_GPIO_PULL_DOWN;
>> +			break;
>> +		case PIN_CONFIG_BIAS_BUS_HOLD:
>> +			pullup = LPI_GPIO_KEEPER;
>> +			break;
>> +		case PIN_CONFIG_BIAS_PULL_UP:
>> +			pullup = LPI_GPIO_PULL_UP;
>> +			break;
>> +		case PIN_CONFIG_INPUT_ENABLE:
>> +			output_enabled = false;
>> +			break;
>> +		case PIN_CONFIG_OUTPUT:
>> +			output_enabled = true;
>> +			lpi_gpio_write(pctrl, group, LPI_GPIO_REG_DIR_CTL,
>> +			output_enabled << LPI_GPIO_REG_DIR_SHIFT);
> 
> Is there a reason why you write this both here and at the bottom of the
> function?
> 
>> +			value = arg;
>> +			break;
>> +		case PIN_CONFIG_DRIVE_STRENGTH:
>> +			strength = arg;
>> +			break;
>> +		case PIN_CONFIG_SLEW_RATE:
>> +			if (arg > LPI_SLEW_RATE_MAX) {
>> +				dev_err(pctldev->dev, "invalid slew rate %u for pin: %d\n",
>> +					arg, group);
>> +				goto set_gpio;
> 
> So if I set an invalid slew rate the remainder of the pinconf/mux
> properties will be ignored and the pin configured with whatever came
> before?
> 
> Wouldn't either return -EINVAL or perhaps just a break make more sense
> here?

May be EINVAL should be good error here! Will fix that!

> 
>> +			}
>> +
>> +			slew_offset = g->slew_offset;
>> +			if (slew_offset == NO_SLEW)
>> +				break;
>> +
>> +			mutex_lock(&pctrl->slew_access_lock);
>> +			val = ioread32(pctrl->slew_base + LPI_SLEW_REG_VAL_CTL);
>> +
>> +			for (i = 0; i < LPI_SLEW_BITS_SIZE; i++) {
>> +				assign_bit(slew_offset, &val, arg & 0x01);
>> +				slew_offset++;
>> +				arg = arg >> 1;
>> +			}
>> +
>> +			iowrite32(val, pctrl->slew_base + LPI_SLEW_REG_VAL_CTL);
>> +
>> +			mutex_unlock(&pctrl->slew_access_lock);
>> +			break;
>> +		default:
>> +			return -EINVAL;
>> +		}
>> +	}
>> +
>> +set_gpio:
>> +	val = lpi_gpio_read(pctrl, group, LPI_GPIO_REG_VAL_CTL);
>> +	val &= ~(LPI_GPIO_REG_PULL_MASK | LPI_GPIO_REG_OUT_STRENGTH_MASK |
>> +		 LPI_GPIO_REG_OE_MASK);
>> +	val |= pullup << LPI_GPIO_REG_PULL_SHIFT;
>> +	val |= LPI_GPIO_DS_TO_VAL(strength);
> 
> FIELD_SET() would make this prettier.

sure will give that a try!

> 
>> +	if (output_enabled)
>> +		val |= value << LPI_GPIO_REG_OE_SHIFT;
>> +
>> +	lpi_gpio_write(pctrl, group, LPI_GPIO_REG_VAL_CTL, val);
>> +	lpi_gpio_write(pctrl, group, LPI_GPIO_REG_DIR_CTL,
>> +		       output_enabled << LPI_GPIO_REG_DIR_SHIFT);
>> +
>> +	return ret;
> 
> ret is untouched since you set it to 0 at the beginning.
will clean this one as well
> 
> Regards,
> Bjorn
> 
>> +}
>> +