Re: [PATCH v4 05/10] mfd: max77650: new core mfd driver

[Bartosz Golaszewski <brgl@bgdev.pl>]

wt., 12 lut 2019 o 09:36 Lee Jones <lee.jones@linaro.org> napisał(a):
>
> On Tue, 05 Feb 2019, Bartosz Golaszewski wrote:
>
> > From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> >
> > Add the core mfd driver for max77650 PMIC. We define five sub-devices
> > for which the drivers will be added in subsequent patches.
> >
> > Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> > ---
> >  drivers/mfd/Kconfig          |  11 ++
> >  drivers/mfd/Makefile         |   1 +
> >  drivers/mfd/max77650.c       | 342 +++++++++++++++++++++++++++++++++++
> >  include/linux/mfd/max77650.h |  59 ++++++
> >  4 files changed, 413 insertions(+)
> >  create mode 100644 drivers/mfd/max77650.c
> >  create mode 100644 include/linux/mfd/max77650.h
> >
> > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> > index 76f9909cf396..a80c3fe80fbe 100644
> > --- a/drivers/mfd/Kconfig
> > +++ b/drivers/mfd/Kconfig
> > @@ -734,6 +734,17 @@ config MFD_MAX77620
> >         provides common support for accessing the device; additional drivers
> >         must be enabled in order to use the functionality of the device.
> >
> > +config MFD_MAX77650
> > +     tristate "Maxim MAX77650/77651 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 MAX77650 and
> > +       MAX77651 Power Management ICs. This is the core multifunction
> > +       driver for interacting with the device.
> > +
> >  config MFD_MAX77686
> >       tristate "Maxim Semiconductor MAX77686/802 PMIC Support"
> >       depends on I2C
> > diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> > index 12980a4ad460..3b912a4015d1 100644
> > --- a/drivers/mfd/Makefile
> > +++ b/drivers/mfd/Makefile
> > @@ -151,6 +151,7 @@ obj-$(CONFIG_MFD_DA9150)  += da9150-core.o
> >
> >  obj-$(CONFIG_MFD_MAX14577)   += max14577.o
> >  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_MAX77843)   += max77843.o
> > diff --git a/drivers/mfd/max77650.c b/drivers/mfd/max77650.c
> > new file mode 100644
> > index 000000000000..7c6164f1fde4
> > --- /dev/null
> > +++ b/drivers/mfd/max77650.c
> > @@ -0,0 +1,342 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +//
> > +// Copyright (C) 2018 BayLibre SAS
> > +// Author: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> > +//
> > +// Core MFD driver for MAXIM 77650/77651 charger/power-supply.
> > +
> > +#include <linux/i2c.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/irq.h>
> > +#include <linux/mfd/core.h>
> > +#include <linux/mfd/max77650.h>
> > +#include <linux/module.h>
> > +#include <linux/of.h>
> > +#include <linux/regmap.h>
> > +#include <linux/slab.h>
> > +
> > +#define MAX77650_INT_GPI_F_MSK               BIT(0)
> > +#define MAX77650_INT_GPI_R_MSK               BIT(1)
> > +#define MAX77650_INT_GPI_MSK \
> > +                     (MAX77650_INT_GPI_F_MSK | MAX77650_INT_GPI_R_MSK)
> > +#define MAX77650_INT_nEN_F_MSK               BIT(2)
> > +#define MAX77650_INT_nEN_R_MSK               BIT(3)
> > +#define MAX77650_INT_TJAL1_R_MSK     BIT(4)
> > +#define MAX77650_INT_TJAL2_R_MSK     BIT(5)
> > +#define MAX77650_INT_DOD_R_MSK               BIT(6)
> > +
> > +#define MAX77650_INT_THM_MSK         BIT(0)
> > +#define MAX77650_INT_CHG_MSK         BIT(1)
> > +#define MAX77650_INT_CHGIN_MSK               BIT(2)
> > +#define MAX77650_INT_TJ_REG_MSK              BIT(3)
> > +#define MAX77650_INT_CHGIN_CTRL_MSK  BIT(4)
> > +#define MAX77650_INT_SYS_CTRL_MSK    BIT(5)
> > +#define MAX77650_INT_SYS_CNFG_MSK    BIT(6)
> > +
> > +#define MAX77650_INT_GLBL_OFFSET     0
> > +#define MAX77650_INT_CHG_OFFSET              1
> > +
> > +#define MAX77650_SBIA_LPM_MASK               BIT(5)
> > +#define MAX77650_SBIA_LPM_DISABLED   0x00
> > +
> > +enum {
> > +     MAX77650_INT_GPI = 0,
> > +     MAX77650_INT_nEN_F,
> > +     MAX77650_INT_nEN_R,
> > +     MAX77650_INT_TJAL1_R,
> > +     MAX77650_INT_TJAL2_R,
> > +     MAX77650_INT_DOD_R,
> > +     MAX77650_INT_THM,
> > +     MAX77650_INT_CHG,
> > +     MAX77650_INT_CHGIN,
> > +     MAX77650_INT_TJ_REG,
> > +     MAX77650_INT_CHGIN_CTRL,
> > +     MAX77650_INT_SYS_CTRL,
> > +     MAX77650_INT_SYS_CNFG,
> > +};
> > +
> > +enum {
> > +     MAX77650_CELL_REGULATOR = 0,
> > +     MAX77650_CELL_CHARGER,
> > +     MAX77650_CELL_GPIO,
> > +     MAX77650_CELL_LED,
> > +     MAX77650_CELL_ONKEY,
> > +     MAX77650_NUM_CELLS,
> > +};
> > +
> > +struct max77650_irq_mapping {
> > +     int cell_num;
> > +     const int *irqs;
> > +     const char *const *irq_names;
> > +     unsigned int num_irqs;
> > +};
> > +
> > +static const int max77650_charger_irqs[] = {
> > +     MAX77650_INT_CHG,
> > +     MAX77650_INT_CHGIN,
> > +};
> > +
> > +static const int max77650_gpio_irqs[] = {
> > +     MAX77650_INT_GPI,
> > +};
> > +
> > +static const int max77650_onkey_irqs[] = {
> > +     MAX77650_INT_nEN_F,
> > +     MAX77650_INT_nEN_R,
> > +};
> > +
> > +static const char *const max77650_charger_irq_names[] = {
> > +     "CHG",
> > +     "CHGIN",
> > +};
> > +
> > +static const char *const max77650_gpio_irq_names[] = {
> > +     "GPI",
> > +};
> > +
> > +static const char *const max77650_onkey_irq_names[] = {
> > +     "nEN_F",
> > +     "nEN_R",
> > +};
> > +
> > +static const struct max77650_irq_mapping max77650_irq_mapping_table[] = {
> > +     {
> > +             .cell_num       = MAX77650_CELL_CHARGER,
> > +             .irqs           = max77650_charger_irqs,
> > +             .irq_names      = max77650_charger_irq_names,
> > +             .num_irqs       = ARRAY_SIZE(max77650_charger_irqs),
> > +     },
> > +     {
> > +             .cell_num       = MAX77650_CELL_GPIO,
> > +             .irqs           = max77650_gpio_irqs,
> > +             .irq_names      = max77650_gpio_irq_names,
> > +             .num_irqs       = ARRAY_SIZE(max77650_gpio_irqs),
> > +     },
> > +     {
> > +             .cell_num       = MAX77650_CELL_ONKEY,
> > +             .irqs           = max77650_onkey_irqs,
> > +             .irq_names      = max77650_onkey_irq_names,
> > +             .num_irqs       = ARRAY_SIZE(max77650_onkey_irqs),
> > +     },
> > +};
>
> This is all a bit convoluted and nasty TBH.
>
> > +static const struct mfd_cell max77650_cells[] = {
> > +     [MAX77650_CELL_REGULATOR] = {
> > +             .name           = "max77650-regulator",
> > +             .of_compatible  = "maxim,max77650-regulator",
> > +     },
> > +     [MAX77650_CELL_CHARGER] = {
> > +             .name           = "max77650-charger",
> > +             .of_compatible  = "maxim,max77650-charger",
> > +     },
> > +     [MAX77650_CELL_GPIO] = {
> > +             .name           = "max77650-gpio",
> > +             .of_compatible  = "maxim,max77650-gpio",
> > +     },
> > +     [MAX77650_CELL_LED] = {
> > +             .name           = "max77650-led",
> > +             .of_compatible  = "maxim,max77650-led",
> > +     },
> > +     [MAX77650_CELL_ONKEY] = {
> > +             .name           = "max77650-onkey",
> > +             .of_compatible  = "maxim,max77650-onkey",
> > +     },
> > +};
>
> Why are you numbering the cells?  There is no need to do this.
>

Just for better readability. It makes sense to me coupled with
MAX77650_NUM_CELLS.

> > +static const struct regmap_irq max77650_irqs[] = {
> > +     [MAX77650_INT_GPI] = {
> > +             .reg_offset             = MAX77650_INT_GLBL_OFFSET,
> > +             .mask                   = MAX77650_INT_GPI_MSK,
> > +             .type = {
> > +                     .type_falling_val       = MAX77650_INT_GPI_F_MSK,
> > +                     .type_rising_val        = MAX77650_INT_GPI_R_MSK,
> > +                     .types_supported        = IRQ_TYPE_EDGE_BOTH,
> > +             },
> > +     },
> > +     [MAX77650_INT_nEN_F] = {
> > +             .reg_offset             = MAX77650_INT_GLBL_OFFSET,
> > +             .mask                   = MAX77650_INT_nEN_F_MSK,
> > +     },
> > +     [MAX77650_INT_nEN_R] = {
> > +             .reg_offset             = MAX77650_INT_GLBL_OFFSET,
> > +             .mask                   = MAX77650_INT_nEN_R_MSK,
> > +     },
> > +     [MAX77650_INT_TJAL1_R] = {
> > +             .reg_offset             = MAX77650_INT_GLBL_OFFSET,
> > +             .mask                   = MAX77650_INT_TJAL1_R_MSK,
> > +     },
> > +     [MAX77650_INT_TJAL2_R] = {
> > +             .reg_offset             = MAX77650_INT_GLBL_OFFSET,
> > +             .mask                   = MAX77650_INT_TJAL2_R_MSK,
> > +     },
> > +     [MAX77650_INT_DOD_R] = {
> > +             .reg_offset             = MAX77650_INT_GLBL_OFFSET,
> > +             .mask                   = MAX77650_INT_DOD_R_MSK,
> > +     },
> > +     [MAX77650_INT_THM] = {
> > +             .reg_offset             = MAX77650_INT_CHG_OFFSET,
> > +             .mask                   = MAX77650_INT_THM_MSK,
> > +     },
> > +     [MAX77650_INT_CHG] = {
> > +             .reg_offset             = MAX77650_INT_CHG_OFFSET,
> > +             .mask                   = MAX77650_INT_CHG_MSK,
> > +     },
> > +     [MAX77650_INT_CHGIN] = {
> > +             .reg_offset             = MAX77650_INT_CHG_OFFSET,
> > +             .mask                   = MAX77650_INT_CHGIN_MSK,
> > +     },
> > +     [MAX77650_INT_TJ_REG] = {
> > +             .reg_offset             = MAX77650_INT_CHG_OFFSET,
> > +             .mask                   = MAX77650_INT_TJ_REG_MSK,
> > +     },
> > +     [MAX77650_INT_CHGIN_CTRL] = {
> > +             .reg_offset             = MAX77650_INT_CHG_OFFSET,
> > +             .mask                   = MAX77650_INT_CHGIN_CTRL_MSK,
> > +     },
> > +     [MAX77650_INT_SYS_CTRL] = {
> > +             .reg_offset             = MAX77650_INT_CHG_OFFSET,
> > +             .mask                   = MAX77650_INT_SYS_CTRL_MSK,
> > +     },
> > +     [MAX77650_INT_SYS_CNFG] = {
> > +             .reg_offset             = MAX77650_INT_CHG_OFFSET,
> > +             .mask                   = MAX77650_INT_SYS_CNFG_MSK,
> > +     },
> > +};
>
> If you get rid of all of the horrible hoop jumping in *_setup_irqs(),
> you can use REGMAP_IRQ_REG() like everyone else does.
>

I could even use it now - except for the first interrupt. I decided to
not use it everywhere as it looks much better that way than having
REGMAP_IRQ_REG() for all definitions and then the first one sticking
out like that. It just looks better.

> > +static const struct regmap_irq_chip max77650_irq_chip = {
> > +     .name                   = "max77650-irq",
> > +     .irqs                   = max77650_irqs,
> > +     .num_irqs               = ARRAY_SIZE(max77650_irqs),
> > +     .num_regs               = 2,
> > +     .status_base            = MAX77650_REG_INT_GLBL,
> > +     .mask_base              = MAX77650_REG_INTM_GLBL,
> > +     .type_in_mask           = true,
> > +     .type_invert            = true,
> > +     .init_ack_masked        = true,
> > +     .clear_on_unmask        = true,
> > +};
> > +
> > +static const struct regmap_config max77650_regmap_config = {
> > +     .name           = "max77650",
> > +     .reg_bits       = 8,
> > +     .val_bits       = 8,
> > +};
> > +
> > +static int max77650_setup_irqs(struct device *dev, struct mfd_cell *cells)
> > +{
> > +     const struct max77650_irq_mapping *mapping;
> > +     struct regmap_irq_chip_data *irq_data;
> > +     struct i2c_client *i2c;
> > +     struct mfd_cell *cell;
> > +     struct resource *res;
> > +     struct regmap *map;
> > +     int i, j, irq, rv;
> > +
> > +     i2c = to_i2c_client(dev);
> > +
> > +     map = dev_get_regmap(dev, NULL);
> > +     if (!map)
> > +             return -ENODEV;
> > +
> > +     rv = devm_regmap_add_irq_chip(dev, map, i2c->irq,
> > +                                   IRQF_ONESHOT | IRQF_SHARED, -1,
>
> What is -1?  Are you sure this isn't defined somewhere?
>

I don't see any define for negative irq_base argument. I can add that
in a separate series and convert the users, but for now I'd stick with
-1.

> > +                                   &max77650_irq_chip, &irq_data);
> > +     if (rv)
> > +             return rv;
> > +
> > +     for (i = 0; i < ARRAY_SIZE(max77650_irq_mapping_table); i++) {
> > +             mapping = &max77650_irq_mapping_table[i];
> > +             cell = &cells[mapping->cell_num];
> > +
> > +             res = devm_kcalloc(dev, sizeof(*res),
> > +                                mapping->num_irqs, GFP_KERNEL);
> > +             if (!res)
> > +                     return -ENOMEM;
> > +
> > +             cell->resources = res;
> > +             cell->num_resources = mapping->num_irqs;
> > +
> > +             for (j = 0; j < mapping->num_irqs; j++) {
> > +                     irq = regmap_irq_get_virq(irq_data, mapping->irqs[j]);
> > +                     if (irq < 0)
> > +                             return irq;
> > +
> > +                     res[j].start = res[j].end = irq;
> > +                     res[j].flags = IORESOURCE_IRQ;
> > +                     res[j].name = mapping->irq_names[j];
> > +             }
> > +     }
>
> This is the first time I've seen it done like this (and I hate it).
>
> Why are you storing the virqs in resources?
>
> I think this is highly irregular.
>

I initially just passed the regmap_irq_chip_data over i2c clientdata
and sub-drivers would look up virq numbers from it but was advised by
Dmitry Torokhov to use resources instead. After implementing it this
way I too think it's more elegant in sub-drivers who can simply do
platform_get_irq_byname(). Do you have a different idea? What exactly
don't you like about this?

> > +     return 0;
> > +}
> > +
> > +static int max77650_i2c_probe(struct i2c_client *i2c)
> > +{
> > +     struct device *dev = &i2c->dev;
> > +     struct mfd_cell *cells;
> > +     struct regmap *map;
> > +     unsigned int val;
> > +     int rv;
> > +
> > +     map = devm_regmap_init_i2c(i2c, &max77650_regmap_config);
> > +     if (IS_ERR(map))
>
> What error messages does devm_regmap_init_i2c() report?  Does it print
> out its own error messages internally?  If not it would be better to
> provide a suitable error message here.
>
> > +             return PTR_ERR(map);
> > +
> > +     rv = regmap_read(map, MAX77650_REG_CID, &val);
> > +     if (rv)
>
> Better to provide a suitable error message here.
>
> > +             return rv;
> > +
> > +     switch (MAX77650_CID_BITS(val)) {
> > +     case MAX77650_CID_77650A:
> > +     case MAX77650_CID_77650C:
> > +     case MAX77650_CID_77651A:
> > +     case MAX77650_CID_77651B:
> > +             break;
> > +     default:
>
> Better to provide a suitable error message here.
>
> > +             return -ENODEV;
> > +     }
> > +
> > +     /*
> > +      * This IC has a low-power mode which reduces the quiescent current
> > +      * consumption to ~5.6uA but is only suitable for systems consuming
> > +      * less than ~2mA. Since this is not likely the case even on
> > +      * linux-based wearables - keep the chip in normal power mode.
> > +      */
> > +     rv = regmap_update_bits(map,
> > +                             MAX77650_REG_CNFG_GLBL,
> > +                             MAX77650_SBIA_LPM_MASK,
> > +                             MAX77650_SBIA_LPM_DISABLED);
> > +     if (rv)
>
> Better to provide a suitable error message here.
>
> > +             return rv;
> > +
> > +     cells = devm_kmemdup(dev, max77650_cells,
> > +                          sizeof(max77650_cells), GFP_KERNEL);
> > +     if (!cells)
> > +             return -ENOMEM;
> > +
> > +     rv = max77650_setup_irqs(dev, cells);
> > +     if (rv)
> > +             return rv;
> > +
> > +     return devm_mfd_add_devices(dev, -1, cells,
>
> Use the correct defines instead of -1.
>

Will do that and add the error messages.

Bart

> `git grep mfd_add_devices`
>
> > +                                 MAX77650_NUM_CELLS, NULL, 0, NULL);
> > +}
> > +
> > +static const struct of_device_id max77650_of_match[] = {
> > +     { .compatible = "maxim,max77650" },
> > +     { }
> > +};
> > +MODULE_DEVICE_TABLE(of, max77650_of_match);
> > +
> > +static struct i2c_driver max77650_i2c_driver = {
> > +     .driver = {
> > +             .name = "max77650",
> > +             .of_match_table = of_match_ptr(max77650_of_match),
> > +     },
> > +     .probe_new = max77650_i2c_probe,
> > +};
> > +module_i2c_driver(max77650_i2c_driver);
> > +
> > +MODULE_DESCRIPTION("MAXIM 77650/77651 multi-function core driver");
> > +MODULE_AUTHOR("Bartosz Golaszewski <bgolaszewski@baylibre.com>");
> > +MODULE_LICENSE("GPL v2");
> > diff --git a/include/linux/mfd/max77650.h b/include/linux/mfd/max77650.h
> > new file mode 100644
> > index 000000000000..c809e211a8cd
> > --- /dev/null
> > +++ b/include/linux/mfd/max77650.h
> > @@ -0,0 +1,59 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * Copyright (C) 2018 BayLibre SAS
> > + * Author: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> > + *
> > + * Common definitions for MAXIM 77650/77651 charger/power-supply.
> > + */
> > +
> > +#ifndef MAX77650_H
> > +#define MAX77650_H
> > +
> > +#include <linux/bits.h>
> > +
> > +#define MAX77650_REG_INT_GLBL                0x00
> > +#define MAX77650_REG_INT_CHG         0x01
> > +#define MAX77650_REG_STAT_CHG_A              0x02
> > +#define MAX77650_REG_STAT_CHG_B              0x03
> > +#define MAX77650_REG_ERCFLAG         0x04
> > +#define MAX77650_REG_STAT_GLBL               0x05
> > +#define MAX77650_REG_INTM_GLBL               0x06
> > +#define MAX77650_REG_INTM_CHG                0x07
> > +#define MAX77650_REG_CNFG_GLBL               0x10
> > +#define MAX77650_REG_CID             0x11
> > +#define MAX77650_REG_CNFG_GPIO               0x12
> > +#define MAX77650_REG_CNFG_CHG_A              0x18
> > +#define MAX77650_REG_CNFG_CHG_B              0x19
> > +#define MAX77650_REG_CNFG_CHG_C              0x1a
> > +#define MAX77650_REG_CNFG_CHG_D              0x1b
> > +#define MAX77650_REG_CNFG_CHG_E              0x1c
> > +#define MAX77650_REG_CNFG_CHG_F              0x1d
> > +#define MAX77650_REG_CNFG_CHG_G              0x1e
> > +#define MAX77650_REG_CNFG_CHG_H              0x1f
> > +#define MAX77650_REG_CNFG_CHG_I              0x20
> > +#define MAX77650_REG_CNFG_SBB_TOP    0x28
> > +#define MAX77650_REG_CNFG_SBB0_A     0x29
> > +#define MAX77650_REG_CNFG_SBB0_B     0x2a
> > +#define MAX77650_REG_CNFG_SBB1_A     0x2b
> > +#define MAX77650_REG_CNFG_SBB1_B     0x2c
> > +#define MAX77650_REG_CNFG_SBB2_A     0x2d
> > +#define MAX77650_REG_CNFG_SBB2_B     0x2e
> > +#define MAX77650_REG_CNFG_LDO_A              0x38
> > +#define MAX77650_REG_CNFG_LDO_B              0x39
> > +#define MAX77650_REG_CNFG_LED0_A     0x40
> > +#define MAX77650_REG_CNFG_LED1_A     0x41
> > +#define MAX77650_REG_CNFG_LED2_A     0x42
> > +#define MAX77650_REG_CNFG_LED0_B     0x43
> > +#define MAX77650_REG_CNFG_LED1_B     0x44
> > +#define MAX77650_REG_CNFG_LED2_B     0x45
> > +#define MAX77650_REG_CNFG_LED_TOP    0x46
> > +
> > +#define MAX77650_CID_MASK            GENMASK(3, 0)
> > +#define MAX77650_CID_BITS(_reg)              (_reg & MAX77650_CID_MASK)
> > +
> > +#define MAX77650_CID_77650A          0x03
> > +#define MAX77650_CID_77650C          0x0a
> > +#define MAX77650_CID_77651A          0x06
> > +#define MAX77650_CID_77651B          0x08
> > +
> > +#endif /* MAX77650_H */
>
> --
> Lee Jones [李琼斯]
> Linaro Services Technical Lead
> Linaro.org │ Open source software for ARM SoCs
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