Re: [PATCH 03/11] mfd: altr_a10sr: Add Altera Arria10 DevKit System Resource Chip

[Thor Thayer <tthayer@opensource.altera.com>]

On 05/09/2016 11:02 AM, Lee Jones wrote:
> On Fri, 22 Apr 2016, tthayer@opensource.altera.com wrote:
>
>> From: Thor Thayer <tthayer@opensource.altera.com>
>>
>> Add support for the Altera Arria10 Development Kit System Resource
>> chip which is implemented using a MAX5 as a external gpio extender,
>> and power supply alarm (hwmon) with the regmap framework over a SPI bus.
>>
>> Signed-off-by: Thor Thayer <tthayer@opensource.altera.com>
>> ---
>>   drivers/mfd/Kconfig              |   11 +++
>>   drivers/mfd/Makefile             |    2 +
>>   drivers/mfd/altera-a10sr.c       |  179 ++++++++++++++++++++++++++++++++++++++
>>   include/linux/mfd/altera-a10sr.h |   87 ++++++++++++++++++
>>   4 files changed, 279 insertions(+)
>>   create mode 100644 drivers/mfd/altera-a10sr.c
>>   create mode 100644 include/linux/mfd/altera-a10sr.h
>>
>> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
>> index eea61e3..4fc27c6 100644
>> --- a/drivers/mfd/Kconfig
>> +++ b/drivers/mfd/Kconfig
>> @@ -18,6 +18,17 @@ config MFD_CS5535
>>   	  This is the core driver for CS5535/CS5536 MFD functions.  This is
>>             necessary for using the board's GPIO and MFGPT functionality.
>>
>> +config MFD_ALTERA_A10SR
>> +       bool "Altera Arria10 DevKit System Resource chip"
>> +       depends on ARCH_SOCFPGA && SPI_MASTER=y && OF
>> +       select REGMAP_SPI
>> +       select MFD_CORE
>> +       help
>> +         Support for the Altera Arria10 DevKit MAX5 System Resource chip
>> +         using the SPI interface. This driver provides common support for
>> +         accessing the external gpio extender (LEDs & buttons) and
>> +         power supply alarms (hwmon).
>> +
>>   config MFD_ACT8945A
>>   	tristate "Active-semi ACT8945A"
>>   	select MFD_CORE
>> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
>> index 5eaa6465d..4f1ff91 100644
>> --- a/drivers/mfd/Makefile
>> +++ b/drivers/mfd/Makefile
>> @@ -203,3 +203,5 @@ intel-soc-pmic-objs		:= intel_soc_pmic_core.o intel_soc_pmic_crc.o
>>   intel-soc-pmic-$(CONFIG_INTEL_PMC_IPC)	+= intel_soc_pmic_bxtwc.o
>>   obj-$(CONFIG_INTEL_SOC_PMIC)	+= intel-soc-pmic.o
>>   obj-$(CONFIG_MFD_MT6397)	+= mt6397-core.o
>> +
>> +obj-$(CONFIG_MFD_ALTERA_A10SR)	+= altera-a10sr.o
>> diff --git a/drivers/mfd/altera-a10sr.c b/drivers/mfd/altera-a10sr.c
>> new file mode 100644
>> index 0000000..2ff08e3
>> --- /dev/null
>> +++ b/drivers/mfd/altera-a10sr.c
>> @@ -0,0 +1,179 @@
>> +/*
>> + * Copyright Altera Corporation (C) 2014-2016. All Rights Reserved
>> + *
>> + * This program is free software; you can redistribute it and/or modify it
>> + * under the terms and conditions of the GNU General Public License,
>> + * version 2, as published by the Free Software Foundation.
>> + *
>> + * This program is distributed in the hope it will be useful, but WITHOUT
>> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
>> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
>> + * more details.
>> + *
>> + * You should have received a copy of the GNU General Public License along with
>> + * this program.  If not, see <http://www.gnu.org/licenses/>.
>> + *
>> + * SPI access for Altera Arria10 MAX5 System Resource Chip
>> + *
>> + * Adapted from DA9052
>> + * Copyright(c) 2011 Dialog Semiconductor Ltd.
>> + * Author: David Dajun Chen <dchen@diasemi.com>
>
> You don't need to carry the copyright or authorship tags over.
>
OK. Thanks,

>> + */
>> +
>> +#include <linux/mfd/altera-a10sr.h>
>> +#include <linux/mfd/core.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/spi/spi.h>
>> +
>> +static const struct mfd_cell altr_a10sr_subdev_info[] = {
>> +	{
>> +		.name = "altr_a10sr_gpio",
>> +		.of_compatible = "altr,a10sr-gpio",
>> +	},
>> +};
>> +
>> +static bool altr_a10sr_reg_readable(struct device *dev, unsigned int reg)
>> +{
>> +	switch (reg) {
>> +	case ALTR_A10SR_VERSION_READ:
>> +	case ALTR_A10SR_LED_REG:
>> +	case ALTR_A10SR_PBDSW_REG:
>> +	case ALTR_A10SR_PBDSW_IRQ_REG:
>> +	case ALTR_A10SR_PWR_GOOD1_REG:
>> +	case ALTR_A10SR_PWR_GOOD2_REG:
>> +	case ALTR_A10SR_PWR_GOOD3_REG:
>> +	case ALTR_A10SR_FMCAB_REG:
>> +	case ALTR_A10SR_HPS_RST_REG:
>> +	case ALTR_A10SR_USB_QSPI_REG:
>> +	case ALTR_A10SR_SFPA_REG:
>> +	case ALTR_A10SR_SFPB_REG:
>> +	case ALTR_A10SR_I2C_M_REG:
>> +	case ALTR_A10SR_WARM_RST_REG:
>> +	case ALTR_A10SR_WR_KEY_REG:
>> +	case ALTR_A10SR_PMBUS_REG:
>> +		return true;
>> +	default:
>> +		return false;
>> +	}
>> +}
>> +
>> +static bool altr_a10sr_reg_writeable(struct device *dev, unsigned int reg)
>> +{
>> +	switch (reg) {
>> +	case ALTR_A10SR_LED_REG:
>> +	case ALTR_A10SR_PBDSW_IRQ_REG:
>> +	case ALTR_A10SR_FMCAB_REG:
>> +	case ALTR_A10SR_HPS_RST_REG:
>> +	case ALTR_A10SR_USB_QSPI_REG:
>> +	case ALTR_A10SR_SFPA_REG:
>> +	case ALTR_A10SR_SFPB_REG:
>> +	case ALTR_A10SR_WARM_RST_REG:
>> +	case ALTR_A10SR_WR_KEY_REG:
>> +	case ALTR_A10SR_PMBUS_REG:
>> +		return true;
>> +	default:
>> +		return false;
>> +	}
>> +}
>> +
>> +static bool altr_a10sr_reg_volatile(struct device *dev, unsigned int reg)
>> +{
>> +	switch (reg) {
>> +	case ALTR_A10SR_PBDSW_REG:
>> +	case ALTR_A10SR_PBDSW_IRQ_REG:
>> +	case ALTR_A10SR_PWR_GOOD1_REG:
>> +	case ALTR_A10SR_PWR_GOOD2_REG:
>> +	case ALTR_A10SR_PWR_GOOD3_REG:
>> +	case ALTR_A10SR_HPS_RST_REG:
>> +	case ALTR_A10SR_I2C_M_REG:
>> +	case ALTR_A10SR_WARM_RST_REG:
>> +	case ALTR_A10SR_WR_KEY_REG:
>> +	case ALTR_A10SR_PMBUS_REG:
>> +		return true;
>> +	default:
>> +		return false;
>> +	}
>> +}
>> +
>> +const struct regmap_config altr_a10sr_regmap_config = {
>> +	.reg_bits = 8,
>> +	.val_bits = 8,
>> +
>> +	.cache_type = REGCACHE_NONE,
>> +
>> +	.use_single_rw = true,
>> +	.read_flag_mask = 1,
>> +	.write_flag_mask = 0,
>> +
>> +	.max_register = ALTR_A10SR_WR_KEY_REG,
>> +	.readable_reg = altr_a10sr_reg_readable,
>> +	.writeable_reg = altr_a10sr_reg_writeable,
>> +	.volatile_reg = altr_a10sr_reg_volatile,
>> +
>> +};
>> +
>> +static int altr_a10sr_spi_probe(struct spi_device *spi)
>> +{
>> +	int ret;
>> +	struct altr_a10sr *a10sr;
>> +
>> +	a10sr = devm_kzalloc(&spi->dev, sizeof(*a10sr),
>> +			     GFP_KERNEL);
>> +	if (!a10sr)
>> +		return -ENOMEM;
>> +
>> +	spi->mode = SPI_MODE_3;
>> +	spi->bits_per_word = 8;
>> +	spi_setup(spi);
>> +
>> +	a10sr->dev = &spi->dev;
>> +
>> +	spi_set_drvdata(spi, a10sr);
>> +
>> +	a10sr->regmap = devm_regmap_init_spi(spi, &altr_a10sr_regmap_config);
>> +	if (IS_ERR(a10sr->regmap)) {
>> +		ret = PTR_ERR(a10sr->regmap);
>> +		dev_err(&spi->dev, "Failed to allocate register map: %d\n",
>> +			ret);
>> +		return ret;
>> +	}
>
> Is this regmap used it more than one driver?
>
Yes, Currently, both the subdevices (GPIO & HWMON) use this regmap to 
communicate to the SPI registers.

>> +	ret = mfd_add_devices(a10sr->dev, PLATFORM_DEVID_AUTO,
>> +			      altr_a10sr_subdev_info,
>> +			      ARRAY_SIZE(altr_a10sr_subdev_info),
>> +			      NULL, 0, NULL);
>> +	if (ret)
>> +		dev_err(a10sr->dev, "Failed to register sub-devices: %d\n",
>> +			ret);
>> +
>> +	return ret;
>> +}
>> +
>> +static int altr_a10sr_spi_remove(struct spi_device *spi)
>> +{
>> +	mfd_remove_devices(&spi->dev);
>> +
>> +	return 0;
>> +}
>
> Use devm_mfd_add_devices() and remove this function.
>
OK.

>> +static const struct of_device_id altr_a10sr_spi_of_match[] = {
>> +	{ .compatible = "altr,a10sr" },
>> +	{ },
>> +};
>> +MODULE_DEVICE_TABLE(of, altr_a10sr_spi_of_match);
>> +
>> +static struct spi_driver altr_a10sr_spi_driver = {
>> +	.probe = altr_a10sr_spi_probe,
>> +	.remove = altr_a10sr_spi_remove,
>
> Remove .remove.
>
>> +	.driver = {
>> +		.name = "altr_a10sr",
>> +		.of_match_table = of_match_ptr(altr_a10sr_spi_of_match),
>> +	},
>> +};
>> +
>> +module_spi_driver(altr_a10sr_spi_driver);
>> +
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_AUTHOR("Thor Thayer <tthayer@opensource.altera.com>");
>> +MODULE_DESCRIPTION("Altera Arria10 DevKit System Resource MFD Driver");
>> diff --git a/include/linux/mfd/altera-a10sr.h b/include/linux/mfd/altera-a10sr.h
>> new file mode 100644
>> index 0000000..c869fe7
>> --- /dev/null
>> +++ b/include/linux/mfd/altera-a10sr.h
>> @@ -0,0 +1,87 @@
>> +/*
>> + * Copyright Altera Corporation (C) 2014-2016. All Rights Reserved
>> + *
>> + * This program is free software; you can redistribute it and/or modify it
>> + * under the terms and conditions of the GNU General Public License,
>> + * version 2, as published by the Free Software Foundation.
>> + *
>> + * This program is distributed in the hope it will be useful, but WITHOUT
>> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
>> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
>> + * more details.
>> + *
>> + * You should have received a copy of the GNU General Public License along with
>> + * this program.  If not, see <http://www.gnu.org/licenses/>.
>> + *
>> + * Declarations for Altera Arria10 MAX5 System Resource Chip
>> + *
>> + * Adapted from DA9052
>> + * Copyright(c) 2011 Dialog Semiconductor Ltd.
>> + * Author: David Dajun Chen <dchen@diasemi.com>
>
> Remove these two lines.
>
Will do. Thanks for reviewing!

>> + */
>> +
>> +#ifndef __MFD_ALTERA_A10SR_H
>> +#define __MFD_ALTERA_A10SR_H
>> +
>> +#include <linux/completion.h>
>> +#include <linux/list.h>
>> +#include <linux/mfd/core.h>
>> +#include <linux/regmap.h>
>> +#include <linux/slab.h>
>> +
>> +/* Write registers are always on even addresses */
>> +#define  WRITE_REG_MASK              0xFE
>> +/* Odd registers are always on odd addresses */
>> +#define  READ_REG_MASK               0x01
>> +
>> +#define ALTR_A10SR_BITS_PER_REGISTER  8
>> +/*
>> + * To find the correct register, we divide the input GPIO by
>> + * the number of GPIO in each register. We then need to multiply
>> + * by 2 because the reads are at odd addresses.
>> + */
>> +#define ALTR_A10SR_REG_OFFSET(X)     (((X) / ALTR_A10SR_BITS_PER_REGISTER) << 1)
>> +#define ALTR_A10SR_REG_BIT(X)        ((X) % ALTR_A10SR_BITS_PER_REGISTER)
>> +#define ALTR_A10SR_REG_BIT_CHG(X, Y) ((X) << ALTR_A10SR_REG_BIT(Y))
>> +#define ALTR_A10SR_REG_BIT_MASK(X)   (1 << ALTR_A10SR_REG_BIT(X))
>> +
>> +/* Arria10 System Controller Register Defines */
>> +#define ALTR_A10SR_NOP                0x00    /* No Change */
>> +#define ALTR_A10SR_VERSION_READ       0x00    /* MAX5 Version Read */
>> +
>> +#define ALTR_A10SR_LED_REG            0x02    /* LED - Upper 4 bits */
>> +/* LED register Bit Definitions */
>> +#define ALTR_A10SR_LED_VALID_SHIFT        4       /* LED - Upper 4 bits valid */
>> +#define ALTR_A10SR_OUT_VALID_RANGE_LO     ALTR_A10SR_LED_VALID_SHIFT
>> +#define ALTR_A10SR_OUT_VALID_RANGE_HI     7
>> +
>> +#define ALTR_A10SR_PBDSW_REG          0x04    /* PB & DIP SW - Input only */
>> +#define ALTR_A10SR_PBDSW_IRQ_REG      0x06    /* PB & DIP SW Flag Clear */
>> +/* Pushbutton & DIP Switch Bit Definitions */
>> +#define ALTR_A10SR_IN_VALID_RANGE_LO      8
>> +#define ALTR_A10SR_IN_VALID_RANGE_HI      15
>> +
>> +#define ALTR_A10SR_PWR_GOOD1_REG      0x08    /* Power Good1 Read */
>> +#define ALTR_A10SR_PWR_GOOD2_REG      0x0A    /* Power Good2 Read */
>> +#define ALTR_A10SR_PWR_GOOD3_REG      0x0C    /* Power Good3 Read */
>> +#define ALTR_A10SR_FMCAB_REG          0x0E    /* FMCA/B & PCIe Pwr Enable */
>> +#define ALTR_A10SR_HPS_RST_REG        0x10    /* HPS Reset */
>> +#define ALTR_A10SR_USB_QSPI_REG       0x12    /* USB, BQSPI, FILE Reset */
>> +#define ALTR_A10SR_SFPA_REG           0x14    /* SFPA Control Reg */
>> +#define ALTR_A10SR_SFPB_REG           0x16    /* SFPB Control Reg */
>> +#define ALTR_A10SR_I2C_M_REG          0x18    /* I2C Master Select */
>> +#define ALTR_A10SR_WARM_RST_REG       0x1A    /* HPS Warm Reset */
>> +#define ALTR_A10SR_WR_KEY_REG         0x1C    /* HPS Warm Reset Key */
>> +#define ALTR_A10SR_PMBUS_REG          0x1E    /* HPS PM Bus */
>> +
>> +/**
>> + * struct altr_a10sr - Altera Max5 MFD device private data structure
>> + * @dev:  : this device
>> + * @regmap: the regmap assigned to the parent device.
>> + */
>> +struct altr_a10sr {
>> +	struct device *dev;
>> +	struct regmap *regmap;
>> +};
>> +
>> +#endif /* __MFD_ALTERA_A10SR_H */
>