Re: [PATCH v1 6/8] watchdog: f71808e_wdt: consolidate variant handling into single array

From: Guenter Roeck
Date: Tue Jun 30 2020 - 17:18:34 EST


On Thu, Jun 11, 2020 at 09:17:47PM +0200, Ahmad Fatoum wrote:
> Driver has two big switches: one to map hardware ID to an enum constant
> one more to map the enum constant to the variant's pin configuration
> routine.
>
> Drop the enum and give every variant an array entry identifying it.
> This arguably simplifies the code by making it a little more compact.
>
> Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>

Please run checkpatch --strict and fix the issues it reports.

> ---
> drivers/watchdog/f71808e_wdt.c | 263 +++++++++++++++------------------
> 1 file changed, 121 insertions(+), 142 deletions(-)
>
> diff --git a/drivers/watchdog/f71808e_wdt.c b/drivers/watchdog/f71808e_wdt.c
> index 9f7823819ed1..9299ad4d4a52 100644
> --- a/drivers/watchdog/f71808e_wdt.c
> +++ b/drivers/watchdog/f71808e_wdt.c
> @@ -110,22 +110,6 @@ module_param(start_withtimeout, uint, 0);
> MODULE_PARM_DESC(start_withtimeout, "Start watchdog timer on module load with"
> " given initial timeout. Zero (default) disables this feature.");
>
> -enum chips { f71808fg, f71858fg, f71862fg, f71868, f71869, f71882fg, f71889fg,
> - f81803, f81865, f81866};
> -
> -static const char *f71808e_names[] = {
> - "f71808fg",
> - "f71858fg",
> - "f71862fg",
> - "f71868",
> - "f71869",
> - "f71882fg",
> - "f71889fg",
> - "f81803",
> - "f81865",
> - "f81866",
> -};
> -
> /* Super-I/O Function prototypes */
> static inline int superio_inb(int base, int reg);
> static inline int superio_inw(int base, int reg);
> @@ -136,9 +120,17 @@ static inline int superio_enter(int base);
> static inline void superio_select(int base, int ld);
> static inline void superio_exit(int base);
>
> +struct watchdog_data;
> +
> +struct f71808e_variant {
> + u16 id;
> + const char *wdt_name; /* NULL if chip lacks watchdog timer */
> + void (*pinconf)(struct watchdog_data *wd);
> +};
> +
> struct watchdog_data {
> unsigned short sioaddr;
> - enum chips type;
> + const struct f71808e_variant *variant;
> unsigned long opened;
> struct mutex lock;
> char expect_close;
> @@ -156,6 +148,12 @@ static struct watchdog_data watchdog = {
> .lock = __MUTEX_INITIALIZER(watchdog.lock),
> };
>
> +static inline bool has_f81865_wdo_conf(struct watchdog_data *wd)
> +{
> + return wd->variant->id == SIO_F81865_ID
> + || wd->variant->id == SIO_F81866_ID;

Nit: unnecessary continuation line (limit is now 100).

> +}
> +
> /* Super I/O functions */
> static inline int superio_inb(int base, int reg)
> {
> @@ -247,7 +245,7 @@ static int watchdog_set_pulse_width(unsigned int pw)
> int err = 0;
> unsigned int t1 = 25, t2 = 125, t3 = 5000;
>
> - if (watchdog.type == f71868) {
> + if (watchdog.variant->id == SIO_F71868_ID) {
> t1 = 30;
> t2 = 150;
> t3 = 6000;
> @@ -309,7 +307,6 @@ static int watchdog_keepalive(void)
> static int watchdog_start(void)
> {
> int err;
> - u8 tmp;
>
> /* Make sure we don't die as soon as the watchdog is enabled below */
> err = watchdog_keepalive();
> @@ -323,81 +320,12 @@ static int watchdog_start(void)
> superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
>
> /* Watchdog pin configuration */
> - switch (watchdog.type) {
> - case f71808fg:
> - /* Set pin 21 to GPIO23/WDTRST#, then to WDTRST# */
> - superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT2, 3);
> - superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT3, 3);
> - break;
> -
> - case f71862fg:
> - if (f71862fg_pin == 63) {
> - /* SPI must be disabled first to use this pin! */
> - superio_clear_bit(watchdog.sioaddr, SIO_REG_ROM_ADDR_SEL, 6);
> - superio_set_bit(watchdog.sioaddr, SIO_REG_MFUNCT3, 4);
> - } else if (f71862fg_pin == 56) {
> - superio_set_bit(watchdog.sioaddr, SIO_REG_MFUNCT1, 1);
> - }
> - break;
> -
> - case f71868:
> - case f71869:
> - /* GPIO14 --> WDTRST# */
> - superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT1, 4);
> - break;
> -
> - case f71882fg:
> - /* Set pin 56 to WDTRST# */
> - superio_set_bit(watchdog.sioaddr, SIO_REG_MFUNCT1, 1);
> - break;
> -
> - case f71889fg:
> - /* set pin 40 to WDTRST# */
> - superio_outb(watchdog.sioaddr, SIO_REG_MFUNCT3,
> - superio_inb(watchdog.sioaddr, SIO_REG_MFUNCT3) & 0xcf);
> - break;
> -
> - case f81803:
> - /* Enable TSI Level register bank */
> - superio_clear_bit(watchdog.sioaddr, SIO_REG_CLOCK_SEL, 3);
> - /* Set pin 27 to WDTRST# */
> - superio_outb(watchdog.sioaddr, SIO_REG_TSI_LEVEL_SEL, 0x5f &
> - superio_inb(watchdog.sioaddr, SIO_REG_TSI_LEVEL_SEL));
> - break;
> -
> - case f81865:
> - /* Set pin 70 to WDTRST# */
> - superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT3, 5);
> - break;
> -
> - case f81866:
> - /*
> - * GPIO1 Control Register when 27h BIT3:2 = 01 & BIT0 = 0.
> - * The PIN 70(GPIO15/WDTRST) is controlled by 2Ch:
> - * BIT5: 0 -> WDTRST#
> - * 1 -> GPIO15
> - */
> - tmp = superio_inb(watchdog.sioaddr, SIO_F81866_REG_PORT_SEL);
> - tmp &= ~(BIT(3) | BIT(0));
> - tmp |= BIT(2);
> - superio_outb(watchdog.sioaddr, SIO_F81866_REG_PORT_SEL, tmp);
> -
> - superio_clear_bit(watchdog.sioaddr, SIO_F81866_REG_GPIO1, 5);
> - break;
> -
> - default:
> - /*
> - * 'default' label to shut up the compiler and catch
> - * programmer errors
> - */
> - err = -ENODEV;
> - goto exit_superio;
> - }
> + watchdog.variant->pinconf(&watchdog);
>
> superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
> superio_set_bit(watchdog.sioaddr, SIO_REG_ENABLE, 0);
>
> - if (watchdog.type == f81865 || watchdog.type == f81866)
> + if (has_f81865_wdo_conf(&watchdog))
> superio_set_bit(watchdog.sioaddr, F81865_REG_WDO_CONF,
> F81865_FLAG_WDOUT_EN);
> else
> @@ -425,7 +353,6 @@ static int watchdog_start(void)
> F71808FG_FLAG_WD_PULSE);
> }
>
> -exit_superio:
> superio_exit(watchdog.sioaddr);
> exit_unlock:
> mutex_unlock(&watchdog.lock);
> @@ -679,7 +606,7 @@ static int __init watchdog_init(int sioaddr)
>
> snprintf(watchdog.ident.identity,
> sizeof(watchdog.ident.identity), "%s watchdog",
> - f71808e_names[watchdog.type]);
> + watchdog.variant->wdt_name);
>
> err = superio_enter(sioaddr);
> if (err)
> @@ -772,73 +699,123 @@ static int __init watchdog_init(int sioaddr)
> return err;
> }
>
> -static int __init f71808e_find(int sioaddr)
> +static void f71808fg_pinconf(struct watchdog_data *wd)
> +{
> + /* Set pin 21 to GPIO23/WDTRST#, then to WDTRST# */
> + superio_clear_bit(wd->sioaddr, SIO_REG_MFUNCT2, 3);
> + superio_clear_bit(wd->sioaddr, SIO_REG_MFUNCT3, 3);
> +}
> +static void f71862fg_pinconf(struct watchdog_data *wd)
> +{
> + if (f71862fg_pin == 63) {
> + /* SPI must be disabled first to use this pin! */
> + superio_clear_bit(wd->sioaddr, SIO_REG_ROM_ADDR_SEL, 6);
> + superio_set_bit(wd->sioaddr, SIO_REG_MFUNCT3, 4);
> + } else if (f71862fg_pin == 56) {
> + superio_set_bit(wd->sioaddr, SIO_REG_MFUNCT1, 1);
> + }
> +}
> +static void f71868_pinconf(struct watchdog_data *wd)
> +{
> + /* GPIO14 --> WDTRST# */
> + superio_clear_bit(wd->sioaddr, SIO_REG_MFUNCT1, 4);
> +}
> +static void f71882fg_pinconf(struct watchdog_data *wd)
> +{
> + /* Set pin 56 to WDTRST# */
> + superio_set_bit(wd->sioaddr, SIO_REG_MFUNCT1, 1);
> +}
> +static void f71889fg_pinconf(struct watchdog_data *wd)
> +{
> + /* set pin 40 to WDTRST# */
> + superio_outb(wd->sioaddr, SIO_REG_MFUNCT3,
> + superio_inb(wd->sioaddr, SIO_REG_MFUNCT3) & 0xcf);
> +}
> +static void f81803_pinconf(struct watchdog_data *wd)
> +{
> + /* Enable TSI Level register bank */
> + superio_clear_bit(wd->sioaddr, SIO_REG_CLOCK_SEL, 3);
> + /* Set pin 27 to WDTRST# */
> + superio_outb(wd->sioaddr, SIO_REG_TSI_LEVEL_SEL, 0x5f &
> + superio_inb(wd->sioaddr, SIO_REG_TSI_LEVEL_SEL));
> +}
> +static void f81865_pinconf(struct watchdog_data *wd)
> +{
> + /* Set pin 70 to WDTRST# */
> + superio_clear_bit(wd->sioaddr, SIO_REG_MFUNCT3, 5);
> +}
> +static void f81866_pinconf(struct watchdog_data *wd)
> +{
> + /*
> + * GPIO1 Control Register when 27h BIT3:2 = 01 & BIT0 = 0.
> + * The PIN 70(GPIO15/WDTRST) is controlled by 2Ch:
> + * BIT5: 0 -> WDTRST#
> + * 1 -> GPIO15
> + */
> + u8 tmp = superio_inb(wd->sioaddr, SIO_F81866_REG_PORT_SEL);
> + tmp &= ~(BIT(3) | BIT(0));
> + tmp |= BIT(2);
> + superio_outb(wd->sioaddr, SIO_F81866_REG_PORT_SEL, tmp);
> +
> + superio_clear_bit(wd->sioaddr, SIO_F81866_REG_GPIO1, 5);
> +}
> +
> +struct f71808e_variant f71808e_variants[] = {
> + { SIO_F71808_ID, "f71808fg", f71808fg_pinconf },
> + { SIO_F71862_ID, "f71862fg", f71862fg_pinconf },
> + { SIO_F71868_ID, "f71868", f71868_pinconf },
> + { SIO_F71869_ID, "f71869", f71868_pinconf },
> + { SIO_F71869A_ID, "f71869", f71868_pinconf },
> + { SIO_F71882_ID, "f71882fg", f71882fg_pinconf },
> + { SIO_F71889_ID, "f71889fg", f71889fg_pinconf },
> + { SIO_F81803_ID, "f81803", f81803_pinconf },
> + { SIO_F81865_ID, "f81865", f81865_pinconf },
> + { SIO_F81866_ID, "f81866", f81866_pinconf },
> + /* Confirmed (by datasheet) not to have a watchdog. */
> + { SIO_F71858_ID, NULL, NULL },
> + { /* sentinel */ }
> +};
> +
> +static struct f71808e_variant __init *f71808e_find(int sioaddr)
> {
> + struct f71808e_variant *variant;
> u16 devid;
> int err = superio_enter(sioaddr);
> if (err)
> - return err;
> + return ERR_PTR(err);
>
> devid = superio_inw(sioaddr, SIO_REG_MANID);
> if (devid != SIO_FINTEK_ID) {
> pr_debug("Not a Fintek device\n");
> - err = -ENODEV;
> - goto exit;
> + superio_exit(sioaddr);
> + return ERR_PTR(-ENODEV);
> }
>
> devid = force_id ? force_id : superio_inw(sioaddr, SIO_REG_DEVID);
> - switch (devid) {
> - case SIO_F71808_ID:
> - watchdog.type = f71808fg;
> - break;
> - case SIO_F71862_ID:
> - watchdog.type = f71862fg;
> - break;
> - case SIO_F71868_ID:
> - watchdog.type = f71868;
> - break;
> - case SIO_F71869_ID:
> - case SIO_F71869A_ID:
> - watchdog.type = f71869;
> - break;
> - case SIO_F71882_ID:
> - watchdog.type = f71882fg;
> - break;
> - case SIO_F71889_ID:
> - watchdog.type = f71889fg;
> - break;
> - case SIO_F71858_ID:
> - /* Confirmed (by datasheet) not to have a watchdog. */
> - err = -ENODEV;
> - goto exit;
> - case SIO_F81803_ID:
> - watchdog.type = f81803;
> - break;
> - case SIO_F81865_ID:
> - watchdog.type = f81865;
> - break;
> - case SIO_F81866_ID:
> - watchdog.type = f81866;
> - break;
> - default:
> - pr_info("Unrecognized Fintek device: %04x\n",
> - (unsigned int)devid);
> - err = -ENODEV;
> - goto exit;
> + for (variant = f71808e_variants; variant->id; variant++) {
> + if (variant->id == devid)
> + break;
> + }
> +
> + if (!variant->wdt_name) {
> + if (!variant->id)
> + pr_info("Unrecognized Fintek device: %04x\n", devid);
> + superio_exit(sioaddr);
> + return ERR_PTR(-ENODEV);
> }
>
> pr_info("Found %s watchdog chip, revision %d\n",
> - f71808e_names[watchdog.type],
> - (int)superio_inb(sioaddr, SIO_REG_DEVREV));
> -exit:
> + variant->wdt_name,
> + superio_inb(sioaddr, SIO_REG_DEVREV));
> +
> superio_exit(sioaddr);
> - return err;
> + return variant;
> }
>
> static int __init f71808e_init(void)
> {
> static const unsigned short addrs[] = { 0x2e, 0x4e };
> - int err = -ENODEV;
> + struct f71808e_variant *variant;
> int i;
>
> if (f71862fg_pin != 63 && f71862fg_pin != 56) {
> @@ -847,12 +824,14 @@ static int __init f71808e_init(void)
> }
>
> for (i = 0; i < ARRAY_SIZE(addrs); i++) {
> - err = f71808e_find(addrs[i]);
> - if (err == 0)
> + variant = f71808e_find(addrs[i]);
> + if (!IS_ERR(variant))
> break;
> }
> if (i == ARRAY_SIZE(addrs))
> - return err;
> + return PTR_ERR(variant);
> +
> + watchdog.variant = variant;
>
> return watchdog_init(addrs[i]);
> }