Re: [PATCH] platform/x86: Add IMS/ZII SCU driver

[Florian Fainelli <f.fainelli@gmail.com>]

On 01/13/2017 08:38 AM, Andy Shevchenko wrote:
> On Wed, Jan 11, 2017 at 11:26 PM, Florian Fainelli <f.fainelli@gmail.com> wrote:
>> From: Guenter Roeck <linux@roeck-us.net>
>>
>> This patch adds support for the IMS (now Zodiac Inflight Innovations)
>> SCU Generation 1/2/3 platform driver. This driver registers all the
>> on-module peripherals: Ethernet switches (Broadcom or Marvell), I2C to
>> GPIO expanders, Kontrom CPLD/I2C master, and more.
>>
>> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
>> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
> 
>> ---
>> Darren,
>>
>> This is against your "for-next" branch thanks!
> 
> I'm going to review this later, though few of comments.
> 
>> +config SCU
> 
> No, no. We have enough mess with Intel's SCU/PMIC here, not add more.

OK OK.

> 
> At least add manufacturer as prefix to option and file name.
> 
> Btw, Darren, would it be good idea to start creating folders to make a
> bit of order in the subsystem? For first I would move Intel's PMIC/SCU
> stuff to somewhere (not sure if it should be per manufacturer or per
> function).
> 
>> +obj-$(CONFIG_SCU)              += scu.o
> 
> For file name as well.
> 
>> +#include <linux/kernel.h>
>> +#include <linux/init.h>
>> +#include <linux/types.h>
>> +#include <linux/string.h>
>> +#include <linux/module.h>
>> +#include <linux/mutex.h>
>> +#include <linux/leds.h>
>> +#include <linux/platform_data/mdio-gpio.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/gpio.h>
>> +#include <linux/err.h>
>> +#include <linux/dmi.h>
>> +#include <linux/i2c.h>
>> +#include <linux/i2c-gpio.h>
>> +#include <linux/version.h>
>> +#include <linux/platform_data/at24.h>
>> +#include <linux/platform_data/pca953x.h>
>> +#include <linux/sysfs.h>
>> +#include <linux/spi/spi.h>
>> +#include <linux/proc_fs.h>
>> +#include <linux/seq_file.h>
>> +#include <linux/netdevice.h>
>> +#include <linux/rtnetlink.h>
>> +#include <linux/nvmem-consumer.h>
> 
> Is it possible to keep them in order?
> Do you need all of them?
> Does it sound like MFD driver + individual drivers?

My understanding of a valid MFD candidate driver is that is partitions a
shared resource space into individual resources that can all be managed
by their respective driver. The KemPLD driver is already a MFD driver,
here, this is more of a superset of all of that and an aggregate
x86-based module that has a number of on-board peripherals.

> 
>> +struct __packed eeprom_data {
>> +       unsigned short length;                  /* 0 - 1 */
>> +       unsigned char checksum;                 /* 2 */
>> +       unsigned char have_gsm_modem;           /* 3 */
>> +       unsigned char have_cdma_modem;          /* 4 */
>> +       unsigned char have_wifi_modem;          /* 5 */
>> +       unsigned char have_rhdd;                /* 6 */
>> +       unsigned char have_dvd;                 /* 7 */
>> +       unsigned char have_tape;                /* 8 */
>> +       unsigned char have_humidity_sensor;     /* 9 */
>> +       unsigned char have_fiber_channel;       /* 10 */
>> +       unsigned char lru_part_number[11];      /* 11 - 21 Box Part Number */
>> +       unsigned char lru_revision[7];          /* 22 - 28 Box Revision */
>> +       unsigned char lru_serial_number[7];     /* 29 - 35 Box Serial Number */
>> +       unsigned char lru_date_of_manufacture[7];
>> +                               /* 36 - 42 Box Date of Manufacture */
>> +       unsigned char board_part_number[11];
>> +                               /* 43 - 53 Base Board Part Number */
>> +       unsigned char board_revision[7];
>> +                               /* 54 - 60 Base Board Revision */
>> +       unsigned char board_serial_number[7];
>> +                               /* 61 - 67 Base Board Serial Number */
>> +       unsigned char board_date_of_manufacture[7];
>> +                               /* 68 - 74 Base Board Date of Manufacture */
>> +       unsigned char board_updated_date_of_manufacture[7];
>> +                               /* 75 - 81 Updated Box Date of Manufacture */
>> +       unsigned char board_updated_revision[7];
>> +                               /* 82 - 88 Updated Box Revision */
>> +       unsigned char dummy[7]; /* 89 - 95 spare/filler */
>> +};
> 
> Would it be better to use fixed-width types here:
> u8
> u16
> 
>> +enum scu_version { scu1, scu2, scu3, unknown };
> 
> MANUFACTURER_SCU_VERSION_x
> ?

OK.

> 
>> +struct scu_data {
>> +       struct device *dev;                     /* SCU platform device */
>> +       struct net_device *netdev;              /* Ethernet device */
>> +       struct platform_device *mdio_dev;       /* MDIO device */
>> +       struct platform_device *dsa_dev;        /* DSA device */
>> +       struct proc_dir_entry *rave_proc_dir;
>> +       struct mutex write_lock;
>> +       struct platform_device *leds_pdev[3];
>> +       struct i2c_adapter *adapter;            /* I2C adapter */
>> +       struct spi_master *master;              /* SPI master */
>> +       struct i2c_client *client[10];          /* I2C clients */
>> +       struct spi_device *spidev[1];           /* SPI devices */
> 
> Comments are good candidates for kernel doc.
> 
>> +       const struct scu_platform_data *pdata;
>> +       bool have_write_magic;
>> +       struct eeprom_data eeprom;
>> +       struct nvmem_device *nvmem;
> 
>> +       bool eeprom_accessible;
>> +       bool eeprom_valid;
> 
> unsigned int flag1:1;
> unsigned int flag2:1;
> 
> ?

Are you concerned with storage, or what motivates the preference for
bitfields vs. bools?

> 
> 
>> +/* platform data */
>> +
>> +static struct gpio_led pca_gpio_leds1[] = {
>> +       {                       /* bit 0 */
>> +        .name = "scu_status:g:RD",
>> +        .gpio = SCU_RD_LED_GPIO,
>> +        .active_low = 1,
>> +        .default_trigger = "heartbeat",
>> +        .default_state = LEDS_GPIO_DEFSTATE_OFF,
>> +        },
>> +       {                       /* bit 1 */
>> +        .name = "scu_status:a:WLess",
>> +        .gpio = SCU_WLES_LED_GPIO,
>> +        .active_low = 1,
>> +        .default_trigger = "none",
>> +        .default_state = LEDS_GPIO_DEFSTATE_OFF,
>> +        },
>> +       {                       /* bit 2 */
>> +        .name = "scu_status:r:LDFail",
>> +        .gpio = SCU_LD_FAIL_LED_GPIO,
>> +        .active_low = 1,
>> +        .default_trigger = "none",
>> +        .default_state = LEDS_GPIO_DEFSTATE_OFF,
>> +        },
>> +       {                       /* bit 3 */
>> +        .name = "scu_status:a:SW",
>> +        .gpio = SCU_SW_LED_GPIO,
>> +        .active_low = 1,
>> +        .default_trigger = "none",
>> +        .default_state = LEDS_GPIO_DEFSTATE_OFF,
>> +       }
>> +};
>> +
>> +static struct gpio_led_platform_data pca_gpio_led_info1 = {
>> +       .leds = pca_gpio_leds1,
>> +       .num_leds = ARRAY_SIZE(pca_gpio_leds1),
>> +};
>> +
>> +static struct gpio_led pca_gpio_leds2[] = {
>> +       {                       /* bit 0 */
>> +        .name = "SD1:g:active",
>> +        .gpio = SCU_SD_ACTIVE_1_GPIO,
>> +        .active_low = 1,
>> +        .default_trigger = "none",
>> +        .default_state = LEDS_GPIO_DEFSTATE_OFF,
>> +        },
>> +       {                       /* bit 1 */
>> +        .name = "SD1:a:error",
>> +        .gpio = SCU_SD_ERROR_1_GPIO,
>> +        .active_low = 1,
>> +        .default_trigger = "none",
>> +        .default_state = LEDS_GPIO_DEFSTATE_OFF,
>> +        },
>> +       {                       /* bit 2 */
>> +        .name = "SD2:g:active",
>> +        .gpio = SCU_SD_ACTIVE_2_GPIO,
>> +        .active_low = 1,
>> +        .default_trigger = "none",
>> +        .default_state = LEDS_GPIO_DEFSTATE_OFF,
>> +        },
>> +       {                       /* bit 3 */
>> +        .name = "SD2:a:error",
>> +        .gpio = SCU_SD_ERROR_2_GPIO,
>> +        .active_low = 1,
>> +        .default_trigger = "none",
>> +        .default_state = LEDS_GPIO_DEFSTATE_OFF,
>> +        },
>> +       {                       /* bit 4 */
>> +        .name = "SD3:g:active",
>> +        .gpio = SCU_SD_ACTIVE_3_GPIO,
>> +        .active_low = 1,
>> +        .default_trigger = "none",
>> +        .default_state = LEDS_GPIO_DEFSTATE_OFF,
>> +        },
>> +       {                       /* bit 5 */
>> +        .name = "SD3:a:error",
>> +        .gpio = SCU_SD_ERROR_3_GPIO,
>> +        .active_low = 1,
>> +        .default_trigger = "none",
>> +        .default_state = LEDS_GPIO_DEFSTATE_OFF,
>> +       }
>> +};
>> +
>> +static struct gpio_led_platform_data pca_gpio_led_info2 = {
>> +       .leds = pca_gpio_leds2,
>> +       .num_leds = ARRAY_SIZE(pca_gpio_leds2),
>> +};
>> +
>> +static struct gpio_led pca_gpio_leds3[] = {
>> +       {                       /* bit 0 */
>> +        .name = "SD4:g:active",
>> +        .gpio = SCU_SD_ACTIVE_4_GPIO,
>> +        .active_low = 1,
>> +        .default_trigger = "none",
>> +        .default_state = LEDS_GPIO_DEFSTATE_OFF,
>> +        },
>> +       {                       /* bit 1 */
>> +        .name = "SD4:a:error",
>> +        .gpio = SCU_SD_ERROR_4_GPIO,
>> +        .active_low = 1,
>> +        .default_trigger = "none",
>> +        .default_state = LEDS_GPIO_DEFSTATE_OFF,
>> +        },
>> +       {                       /* bit 2 */
>> +        .name = "SD5:g:active",
>> +        .gpio = SCU_SD_ACTIVE_5_GPIO,
>> +        .active_low = 1,
>> +        .default_trigger = "none",
>> +        .default_state = LEDS_GPIO_DEFSTATE_OFF,
>> +        },
>> +       {                       /* bit 3 */
>> +        .name = "SD5:a:error",
>> +        .gpio = SCU_SD_ERROR_5_GPIO,
>> +        .active_low = 1,
>> +        .default_trigger = "none",
>> +        .default_state = LEDS_GPIO_DEFSTATE_OFF,
>> +        },
>> +       {                       /* bit 4 */
>> +        .name = "SD6:g:active",
>> +        .gpio = SCU_SD_ACTIVE_6_GPIO,
>> +        .active_low = 1,
>> +        .default_trigger = "none",
>> +        .default_state = LEDS_GPIO_DEFSTATE_OFF,
>> +        },
>> +       {                       /* bit 5 */
>> +        .name = "SD6:a:error",
>> +        .gpio = SCU_SD_ERROR_6_GPIO,
>> +        .active_low = 1,
>> +        .default_trigger = "none",
>> +        .default_state = LEDS_GPIO_DEFSTATE_OFF,
>> +       }
>> +};
> 
> Hmm... Can you utilize device tree for that?

Not really an option here

> Or built-in device properties?

Not clear what you mean by that, can you expand?

> 
>> +static struct gpio_led_platform_data pca_gpio_led_info3 = {
>> +       .leds = pca_gpio_leds3,
>> +       .num_leds = ARRAY_SIZE(pca_gpio_leds3),
>> +};
>> +
>> +static void pca_leds_register(struct device *parent,
>> +                             struct scu_data *data)
>> +{
>> +       data->leds_pdev[0] =
>> +               platform_device_register_data(parent, "leds-gpio", 1,
>> +                                             &pca_gpio_led_info1,
>> +                                             sizeof(pca_gpio_led_info1));
>> +       data->leds_pdev[1] =
>> +               platform_device_register_data(parent, "leds-gpio", 2,
>> +                                             &pca_gpio_led_info2,
>> +                                             sizeof(pca_gpio_led_info2));
>> +       data->leds_pdev[2] =
>> +               platform_device_register_data(parent, "leds-gpio", 3,
>> +                                             &pca_gpio_led_info3,
>> +                                             sizeof(pca_gpio_led_info3));
>> +}
> 
> It really sounds like MFD to me.

It's more of a board description of attached peripherals (all of them),
more than a multi-function device, the whole module is by nature, "multi
function" since it has a bunch of different I/Os and on-module peripherals.

Thanks for your feedback!
-- 
Florian