Re: [PATCH 05/18] mfd: Add support for Kontron sl28cpld management controller

[Michael Walle <michael@walle.cc>]

Am 2020-03-18 04:28, schrieb Guenter Roeck:
> On 3/17/20 1:50 PM, Michael Walle wrote:
>> This patch adds core support for the board management controller found
>> on the SMARC-sAL28 board. It consists of the following functions:
>>  - watchdog
>>  - GPIO controller
>>  - PWM controller
>>  - fan sensor
>>  - interrupt controller
>> 
>> At the moment, this controller is used on the Kontron SMARC-sAL28 
>> board.
>> 
>> Signed-off-by: Michael Walle <michael@walle.cc>
>> ---
>>  drivers/mfd/Kconfig    |  21 ++++++
>>  drivers/mfd/Makefile   |   2 +
>>  drivers/mfd/sl28cpld.c | 155 
>> +++++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 178 insertions(+)
>>  create mode 100644 drivers/mfd/sl28cpld.c
>> 
>> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
>> index 3c547ed575e6..01588c366476 100644
>> --- a/drivers/mfd/Kconfig
>> +++ b/drivers/mfd/Kconfig
>> @@ -2059,5 +2059,26 @@ config SGI_MFD_IOC3
>>  	  If you have an SGI Origin, Octane, or a PCI IOC3 card,
>>  	  then say Y. Otherwise say N.
>> 
>> +config MFD_SL28CPLD
>> +	tristate "Kontron sl28 core driver"
>> +	depends on I2C=y
> 
> Why I2C=y and not just I2C ?

Oh this should be changed in the next patch which adds
interrupt controller support, where I2C=y is needed, correct?

-michael

> 
>> +	depends on OF
>> +	select REGMAP_I2C
>> +	select REGMAP_IRQ
>> +	select SL28CPLD_IRQ
>> +	select MFD_CORE
>> +	help
>> +	  This option enables support for the board management controller
>> +	  found on the Kontron sl28 CPLD. You have to select individual
>> +	  functions, such as watchdog, GPIO, etc, under the corresponding 
>> menus
>> +	  in order to enable them.
>> +
>> +	  Currently supported boards are:
>> +
>> +		Kontron SMARC-sAL28
>> +
>> +	  To compile this driver as a module, choose M here: the module will 
>> be
>> +	  called sl28cpld.
>> +
>>  endmenu
>>  endif
>> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
>> index f935d10cbf0f..9bc38863b9c7 100644
>> --- a/drivers/mfd/Makefile
>> +++ b/drivers/mfd/Makefile
>> @@ -259,3 +259,5 @@ obj-$(CONFIG_MFD_ROHM_BD718XX)	+= rohm-bd718x7.o
>>  obj-$(CONFIG_MFD_STMFX) 	+= stmfx.o
>> 
>>  obj-$(CONFIG_SGI_MFD_IOC3)	+= ioc3.o
>> +
>> +obj-$(CONFIG_MFD_SL28CPLD)	+= sl28cpld.o
>> diff --git a/drivers/mfd/sl28cpld.c b/drivers/mfd/sl28cpld.c
>> new file mode 100644
>> index 000000000000..789f21f90752
>> --- /dev/null
>> +++ b/drivers/mfd/sl28cpld.c
>> @@ -0,0 +1,155 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * MFD core for the CPLD on a SMARC-sAL28 board.
>> + *
>> + * Copyright 2019 Kontron Europe GmbH
>> + */
>> +
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/of_address.h>
>> +#include <linux/of_platform.h>
>> +#include <linux/i2c.h>
>> +#include <linux/regmap.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/mfd/core.h>
>> +
>> +#define SL28CPLD_VERSION 0x03
>> +#define SL28CPLD_WATCHDOG_BASE 0x4
>> +#define SL28CPLD_HWMON_FAN_BASE 0xb
>> +#define SL28CPLD_PWM0_BASE 0xc
>> +#define SL28CPLD_PWM1_BASE 0xe
>> +#define SL28CPLD_GPIO0_BASE 0x10
>> +#define SL28CPLD_GPIO1_BASE 0x15
>> +#define SL28CPLD_GPO_BASE 0x1a
>> +#define SL28CPLD_GPI_BASE 0x1b
>> +#define SL28CPLD_INTC_BASE 0x1c
>> +
>> +/* all subdevices share the same IRQ */
>> +#define SL28CPLD_IRQ 0
>> +
>> +#define SL28CPLD_MIN_REQ_VERSION 14
>> +
>> +struct sl28cpld {
>> +	struct device *dev;
>> +	struct regmap *regmap;
>> +};
>> +
>> +static const struct regmap_config sl28cpld_regmap_config = {
>> +	.reg_bits = 8,
>> +	.val_bits = 8,
>> +	.reg_stride = 1,
>> +};
>> +
>> +static struct resource sl28cpld_watchdog_resources[] = {
>> +	DEFINE_RES_REG(SL28CPLD_WATCHDOG_BASE, 1),
>> +};
>> +
>> +static struct resource sl28cpld_hwmon_fan_resources[] = {
>> +	DEFINE_RES_REG(SL28CPLD_HWMON_FAN_BASE, 1),
>> +};
>> +
>> +static struct resource sl28cpld_pwm0_resources[] = {
>> +	DEFINE_RES_REG(SL28CPLD_PWM0_BASE, 1),
>> +};
>> +
>> +static struct resource sl28cpld_pwm1_resources[] = {
>> +	DEFINE_RES_REG(SL28CPLD_PWM1_BASE, 1),
>> +};
>> +
>> +static struct resource sl28cpld_gpio0_resources[] = {
>> +	DEFINE_RES_REG(SL28CPLD_GPIO0_BASE, 1),
>> +	DEFINE_RES_IRQ(SL28CPLD_IRQ),
>> +};
>> +
>> +static struct resource sl28cpld_gpio1_resources[] = {
>> +	DEFINE_RES_REG(SL28CPLD_GPIO1_BASE, 1),
>> +	DEFINE_RES_IRQ(SL28CPLD_IRQ),
>> +};
>> +
>> +static struct resource sl28cpld_gpo_resources[] = {
>> +	DEFINE_RES_REG(SL28CPLD_GPO_BASE, 1),
>> +};
>> +
>> +static struct resource sl28cpld_gpi_resources[] = {
>> +	DEFINE_RES_REG(SL28CPLD_GPI_BASE, 1),
>> +};
>> +
>> +static struct resource sl28cpld_intc_resources[] = {
>> +	DEFINE_RES_REG(SL28CPLD_INTC_BASE, 1),
>> +	DEFINE_RES_IRQ(SL28CPLD_IRQ),
>> +};
>> +
>> +static const struct mfd_cell sl28cpld_devs[] = {
>> +	OF_MFD_CELL("sl28cpld-wdt", sl28cpld_watchdog_resources, NULL, 0, 0,
>> +		    "kontron,sl28cpld-wdt"),
>> +	OF_MFD_CELL("sl28cpld-fan", sl28cpld_hwmon_fan_resources, NULL, 0, 
>> 0,
>> +		    "kontron,sl28cpld-fan"),
>> +	OF_MFD_CELL("sl28cpld-pwm", sl28cpld_pwm0_resources, NULL, 0, 0,
>> +		    "kontron,sl28cpld-pwm"),
>> +	OF_MFD_CELL("sl28cpld-pwm", sl28cpld_pwm1_resources, NULL, 0, 1,
>> +		    "kontron,sl28cpld-pwm"),
>> +	OF_MFD_CELL("sl28cpld-gpio", sl28cpld_gpio0_resources, NULL, 0, 0,
>> +		    "kontron,sl28cpld-gpio"),
>> +	OF_MFD_CELL("sl28cpld-gpio", sl28cpld_gpio1_resources, NULL, 0, 1,
>> +		    "kontron,sl28cpld-gpio"),
>> +	OF_MFD_CELL("sl28cpld-gpo", sl28cpld_gpo_resources, NULL, 0, 0,
>> +		    "kontron,sl28cpld-gpo"),
>> +	OF_MFD_CELL("sl28cpld-gpi", sl28cpld_gpi_resources, NULL, 0, 0,
>> +		    "kontron,sl28cpld-gpi"),
>> +	OF_MFD_CELL("sl28cpld-intc", sl28cpld_intc_resources, NULL, 0, 0,
>> +		    "kontron,sl28cpld-intc"),
>> +};
>> +
>> +static int sl28cpld_probe(struct i2c_client *i2c)
>> +{
>> +	struct sl28cpld *sl28cpld;
>> +	struct device *dev = &i2c->dev;
>> +	unsigned int cpld_version;
>> +	int ret;
>> +
>> +	sl28cpld = devm_kzalloc(dev, sizeof(*sl28cpld), GFP_KERNEL);
>> +	if (!sl28cpld)
>> +		return -ENOMEM;
>> +
>> +	sl28cpld->regmap = devm_regmap_init_i2c(i2c, 
>> &sl28cpld_regmap_config);
>> +	if (IS_ERR(sl28cpld->regmap))
>> +		return PTR_ERR(sl28cpld->regmap);
>> +
>> +	ret = regmap_read(sl28cpld->regmap, SL28CPLD_VERSION, 
>> &cpld_version);
>> +	if (ret)
>> +		return ret;
>> +
>> +	if (cpld_version < SL28CPLD_MIN_REQ_VERSION) {
>> +		dev_err(dev, "unsupported CPLD version %d\n", cpld_version);
>> +		return -ENODEV;
>> +	}
>> +
>> +	sl28cpld->dev = dev;
>> +	i2c_set_clientdata(i2c, sl28cpld);
>> +
>> +	dev_info(dev, "successfully probed. CPLD version %d\n", 
>> cpld_version);
>> +
>> +	return devm_mfd_add_devices(dev, -1, sl28cpld_devs,
>> +				    ARRAY_SIZE(sl28cpld_devs), NULL,
>> +				    i2c->irq, NULL);
>> +}
>> +
>> +static const struct of_device_id sl28cpld_of_match[] = {
>> +	{ .compatible = "kontron,sl28cpld", },
>> +	{}
>> +};
>> +MODULE_DEVICE_TABLE(of, sl28cpld_of_match);
>> +
>> +static struct i2c_driver sl28cpld_driver = {
>> +	.probe_new = sl28cpld_probe,
>> +	.driver = {
>> +		.name = "sl28cpld",
>> +		.of_match_table = of_match_ptr(sl28cpld_of_match),
>> +	},
>> +};
>> +module_i2c_driver(sl28cpld_driver);
>> +
>> +MODULE_DESCRIPTION("sl28cpld MFD Core Driver");
>> +MODULE_LICENSE("GPL");
>>