On Tue, 19 Oct 2021, Luca Ceresoli wrote:
> Add a simple driver for the Maxim MAX77714 PMIC, supporting RTC and
> watchdog only.
>
> Signed-off-by: Luca Ceresoli <luca@xxxxxxxxxxxxxxxx>
>
> ---
>
> Changes in v2:
> - fix "watchdog" word in heading comment (Guenter Roeck)
> - move struct max77714 to .c file (Krzysztof Kozlowski)
> - change include guard format (Krzysztof Kozlowski)
> - allow building as a module (Krzysztof Kozlowski)
> - remove of_match_ptr usage (Krzysztof Kozlowski / lkp)
> (Reported-by: kernel test robot <lkp@xxxxxxxxx>)
> ---
> MAINTAINERS | 2 +
> drivers/mfd/Kconfig | 14 +++
> drivers/mfd/Makefile | 1 +
> drivers/mfd/max77714.c | 165 +++++++++++++++++++++++++++++++++++
> include/linux/mfd/max77714.h | 60 +++++++++++++
> 5 files changed, 242 insertions(+)
> create mode 100644 drivers/mfd/max77714.c
> create mode 100644 include/linux/mfd/max77714.h
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 514ff4a735e5..abd9de8a9d99 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -11390,6 +11390,8 @@ MAXIM MAX77714 PMIC MFD DRIVER
> M: Luca Ceresoli <luca@xxxxxxxxxxxxxxxx>
> S: Maintained
> F: Documentation/devicetree/bindings/mfd/maxim,max77714.yaml
> +F: drivers/mfd/max77714.c
> +F: include/linux/mfd/max77714.h
>
> MAXIM MAX77802 PMIC REGULATOR DEVICE DRIVER
> M: Javier Martinez Canillas <javier@xxxxxxxxxxxx>
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index ca0edab91aeb..295a04b479c6 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -853,6 +853,20 @@ config MFD_MAX77693
> additional drivers must be enabled in order to use the functionality
> of the device.
>
> +config MFD_MAX77714
> + tristate "Maxim Semiconductor MAX77714 PMIC Support"
> + depends on I2C
> + depends on OF || COMPILE_TEST
> + select MFD_CORE
> + select REGMAP_I2C
> + help
> + Say yes here to add support for Maxim Semiconductor MAX77714.
> + This is a Power Management IC with 4 buck regulators, 9
> + low-dropout regulators, 8 GPIOs, RTC, watchdog etc. This driver
> + provides common support for accessing the device; additional
> + drivers must be enabled in order to use each functionality of the
> + device.
> +
> config MFD_MAX77843
> bool "Maxim Semiconductor MAX77843 PMIC Support"
> depends on I2C=y
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 2ba6646e874c..fe43f2fdd5cb 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -163,6 +163,7 @@ obj-$(CONFIG_MFD_MAX77620) += max77620.o
> obj-$(CONFIG_MFD_MAX77650) += max77650.o
> obj-$(CONFIG_MFD_MAX77686) += max77686.o
> obj-$(CONFIG_MFD_MAX77693) += max77693.o
> +obj-$(CONFIG_MFD_MAX77714) += max77714.o
> obj-$(CONFIG_MFD_MAX77843) += max77843.o
> obj-$(CONFIG_MFD_MAX8907) += max8907.o
> max8925-objs := max8925-core.o max8925-i2c.o
> diff --git a/drivers/mfd/max77714.c b/drivers/mfd/max77714.c
> new file mode 100644
> index 000000000000..4b49d16fe199
> --- /dev/null
> +++ b/drivers/mfd/max77714.c
> @@ -0,0 +1,165 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Maxim MAX77714 MFD Driver
> + *
> + * Copyright (C) 2021 Luca Ceresoli
> + * Author: Luca Ceresoli <luca@xxxxxxxxxxxxxxxx>
> + */
> +
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/mfd/core.h>
> +#include <linux/mfd/max77714.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/regmap.h>
> +
> +struct max77714 {
> + struct device *dev;
> + struct regmap *regmap;
> + struct regmap_irq_chip_data *irq_data;
Is this used outside of .probe()?
> + int irq;
> +};
> +
> +static const struct regmap_range max77714_readable_ranges[] = {
> + regmap_reg_range(MAX77714_INT_TOP, MAX77714_INT_TOP),
> + regmap_reg_range(MAX77714_INT_TOPM, MAX77714_INT_TOPM),
> + regmap_reg_range(MAX77714_32K_STATUS, MAX77714_32K_CONFIG),
> + regmap_reg_range(MAX77714_CNFG_GLBL2, MAX77714_CNFG2_ONOFF),
> +};
> +
> +static const struct regmap_range max77714_writable_ranges[] = {
> + regmap_reg_range(MAX77714_INT_TOPM, MAX77714_INT_TOPM),
> + regmap_reg_range(MAX77714_32K_CONFIG, MAX77714_32K_CONFIG),
> + regmap_reg_range(MAX77714_CNFG_GLBL2, MAX77714_CNFG2_ONOFF),
> +};
> +
> +static const struct regmap_access_table max77714_readable_table = {
> + .yes_ranges = max77714_readable_ranges,
> + .n_yes_ranges = ARRAY_SIZE(max77714_readable_ranges),
> +};
> +
> +static const struct regmap_access_table max77714_writable_table = {
> + .yes_ranges = max77714_writable_ranges,
> + .n_yes_ranges = ARRAY_SIZE(max77714_writable_ranges),
> +};
> +
> +static const struct regmap_config max77714_regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> + .max_register = MAX77714_CNFG2_ONOFF,
> + .rd_table = &max77714_readable_table,
> + .wr_table = &max77714_writable_table,
> +};
> +
> +static const struct regmap_irq max77714_top_irqs[] = {
> + REGMAP_IRQ_REG(MAX77714_IRQ_TOP_ONOFF, 0, MAX77714_INT_TOP_ONOFF),
> + REGMAP_IRQ_REG(MAX77714_IRQ_TOP_RTC, 0, MAX77714_INT_TOP_RTC),
> + REGMAP_IRQ_REG(MAX77714_IRQ_TOP_GPIO, 0, MAX77714_INT_TOP_GPIO),
> + REGMAP_IRQ_REG(MAX77714_IRQ_TOP_LDO, 0, MAX77714_INT_TOP_LDO),
> + REGMAP_IRQ_REG(MAX77714_IRQ_TOP_SD, 0, MAX77714_INT_TOP_SD),
> + REGMAP_IRQ_REG(MAX77714_IRQ_TOP_GLBL, 0, MAX77714_INT_TOP_GLBL),
> +};
> +
> +static const struct regmap_irq_chip max77714_irq_chip = {
> + .name = "max77714-pmic",
> + .status_base = MAX77714_INT_TOP,
> + .mask_base = MAX77714_INT_TOPM,
> + .num_regs = 1,
> + .irqs = max77714_top_irqs,
> + .num_irqs = ARRAY_SIZE(max77714_top_irqs),
> +};
> +
> +static const struct mfd_cell max77714_cells[] = {
> + { .name = "max77714-watchdog" },
> + { .name = "max77714-rtc" },
> +};
Please place this at the top of the file.
> +/*
> + * MAX77714 initially uses the internal, low precision oscillator. Enable
> + * the external oscillator by setting the XOSC_RETRY bit. If the external
> + * oscillator is not OK (probably not installed) this has no effect.
> + */
> +static int max77714_setup_xosc(struct max77714 *chip)
May as well just pass 'dev' and 'regmap' to this function and do away
with the superfluous struct along with all of it's memory management
handling requirements.
> +{
> + /* Internal Crystal Load Capacitance, indexed by value of 32KLOAD bits */
> + static const unsigned int load_cap[4] = {0, 10, 12, 22};
Probably best to define these magic numbers.
> + unsigned int load_cap_idx;
> + unsigned int status;
> + int err;
> +
> + err = regmap_update_bits(chip->regmap, MAX77714_32K_CONFIG,
> + MAX77714_32K_CONFIG_XOSC_RETRY,
> + MAX77714_32K_CONFIG_XOSC_RETRY);
> + if (err)
> + return dev_err_probe(chip->dev, err, "cannot configure XOSC\n");
Error messages should be clear:
"Failed to configure the external oscillator"
Same for the messages below.
> + err = regmap_read(chip->regmap, MAX77714_32K_STATUS, &status);
> + if (err)
> + return dev_err_probe(chip->dev, err, "cannot read XOSC status\n");
> +
> + load_cap_idx = (status >> MAX77714_32K_STATUS_32KLOAD_SHF)
> + & MAX77714_32K_STATUS_32KLOAD_MSK;
> +
> + dev_info(chip->dev, "Using %s oscillator, %d pF load cap\n",
> + status & MAX77714_32K_STATUS_32KSOURCE ? "internal" : "external",
> + load_cap[load_cap_idx]);
> +
> + return 0;
> +}
> +
> +static int max77714_probe(struct i2c_client *client)
> +{
> + struct max77714 *chip;
> + int err;
> +
> + chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
> + if (!chip)
> + return -ENOMEM;
> +
> + i2c_set_clientdata(client, chip);
Where else is this used?
The definition appears to be local.
> + chip->dev = &client->dev;
> +
> + chip->regmap = devm_regmap_init_i2c(client, &max77714_regmap_config);
> + if (IS_ERR(chip->regmap))
> + return dev_err_probe(chip->dev, PTR_ERR(chip->regmap),
> + "failed to initialise regmap\n");
> +
> + err = max77714_setup_xosc(chip);
> + if (err)
> + return err;
> +
> + err = devm_regmap_add_irq_chip(chip->dev, chip->regmap, client->irq,
> + IRQF_ONESHOT | IRQF_SHARED, 0,
> + &max77714_irq_chip, &chip->irq_data);
> + if (err)
> + return dev_err_probe(chip->dev, err, "failed to add PMIC irq chip\n");
IRQ
> + err = devm_mfd_add_devices(chip->dev, PLATFORM_DEVID_NONE,
> + max77714_cells, ARRAY_SIZE(max77714_cells),
> + NULL, 0, NULL);
> + if (err)
> + return dev_err_probe(chip->dev, err, "failed adding MFD children\n");
"Failed to register child devices"
> + return 0;
> +}
> +
> +static const struct of_device_id max77714_dt_match[] = {
> + { .compatible = "maxim,max77714" },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, max77714_dt_match);
> +
> +static struct i2c_driver max77714_driver = {
> + .driver = {
> + .name = "max77714",
> + .of_match_table = max77714_dt_match,
> + },
> + .probe_new = max77714_probe,
> +};
> +module_i2c_driver(max77714_driver);
> +
> +MODULE_DESCRIPTION("Maxim MAX77714 MFD core driver");
> +MODULE_AUTHOR("Luca Ceresoli <luca@xxxxxxxxxxxxxxxx>");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/mfd/max77714.h b/include/linux/mfd/max77714.h
> new file mode 100644
> index 000000000000..4a274592d4f2
> --- /dev/null
> +++ b/include/linux/mfd/max77714.h
> @@ -0,0 +1,60 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Maxim MAX77714 Register and data structures definition.
> + *
> + * Copyright (C) 2021 Luca Ceresoli
> + * Author: Luca Ceresoli <luca@xxxxxxxxxxxxxxxx>
> + */
> +
> +#ifndef __LINUX_MFD_MAX77714_H_
> +#define __LINUX_MFD_MAX77714_H_
> +
> +#include <linux/bits.h>
> +
> +#define MAX77714_INT_TOP 0x00
> +#define MAX77714_INT_TOPM 0x07 /* Datasheet says "read only", but it is RW */
> +
> +#define MAX77714_INT_TOP_ONOFF BIT(1)
> +#define MAX77714_INT_TOP_RTC BIT(3)
> +#define MAX77714_INT_TOP_GPIO BIT(4)
> +#define MAX77714_INT_TOP_LDO BIT(5)
> +#define MAX77714_INT_TOP_SD BIT(6)
> +#define MAX77714_INT_TOP_GLBL BIT(7)
> +
> +#define MAX77714_32K_STATUS 0x30
> +#define MAX77714_32K_STATUS_SIOSCOK BIT(5)
> +#define MAX77714_32K_STATUS_XOSCOK BIT(4)
> +#define MAX77714_32K_STATUS_32KSOURCE BIT(3)
> +#define MAX77714_32K_STATUS_32KLOAD_MSK 0x3
> +#define MAX77714_32K_STATUS_32KLOAD_SHF 1
> +#define MAX77714_32K_STATUS_CRYSTAL_CFG BIT(0)
> +
> +#define MAX77714_32K_CONFIG 0x31
> +#define MAX77714_32K_CONFIG_XOSC_RETRY BIT(4)
> +
> +#define MAX77714_CNFG_GLBL2 0x91
> +#define MAX77714_WDTEN BIT(2)
> +#define MAX77714_WDTSLPC BIT(3)
> +#define MAX77714_TWD_MASK 0x3
> +#define MAX77714_TWD_2s 0x0
> +#define MAX77714_TWD_16s 0x1
> +#define MAX77714_TWD_64s 0x2
> +#define MAX77714_TWD_128s 0x3
> +
> +#define MAX77714_CNFG_GLBL3 0x92
> +#define MAX77714_WDTC BIT(0)
> +
> +#define MAX77714_CNFG2_ONOFF 0x94
> +#define MAX77714_WD_RST_WK BIT(5)
> +
> +/* Interrupts */
> +enum {
> + MAX77714_IRQ_TOP_ONOFF,
> + MAX77714_IRQ_TOP_RTC, /* Real-time clock */
> + MAX77714_IRQ_TOP_GPIO, /* GPIOs */
> + MAX77714_IRQ_TOP_LDO, /* Low-dropout regulators */
> + MAX77714_IRQ_TOP_SD, /* Step-down regulators */
> + MAX77714_IRQ_TOP_GLBL, /* "Global resources": Low-Battery, overtemp... */
> +};
> +
> +#endif /* __LINUX_MFD_MAX77714_H_ */
--
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