Re: [PATCH platform-next 09/16] platform: mellanox: mlx-platform: Add reset callback

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

On Mon, 14 Aug 2023, Vadim Pasternak wrote:

> On L1 switches reset should include special actions against CPLD device
> for performing graceful operations.
> For that purpose, special PLATFORM_RESET# signal should be indicated.
> 
> Signed-off-by: Vadim Pasternak <vadimp@nvidia.com>
> Reviewed-by: Michael Shych <michaelsh@nvidia.com>
> ---
>  drivers/platform/x86/mlx-platform.c | 45 +++++++++++++++++++++++++++--
>  1 file changed, 43 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/platform/x86/mlx-platform.c b/drivers/platform/x86/mlx-platform.c
> index 1010064d54e9..b577ce572ab1 100644
> --- a/drivers/platform/x86/mlx-platform.c
> +++ b/drivers/platform/x86/mlx-platform.c
> @@ -35,6 +35,7 @@
>  #define MLXPLAT_CPLD_LPC_REG_CPLD3_PN1_OFFSET	0x09
>  #define MLXPLAT_CPLD_LPC_REG_CPLD4_PN_OFFSET	0x0a
>  #define MLXPLAT_CPLD_LPC_REG_CPLD4_PN1_OFFSET	0x0b
> +#define MLXPLAT_CPLD_LPC_REG_RESET_GP1_OFFSET	0x17
>  #define MLXPLAT_CPLD_LPC_REG_RESET_GP2_OFFSET	0x19
>  #define MLXPLAT_CPLD_LPC_REG_RESET_GP4_OFFSET	0x1c
>  #define MLXPLAT_CPLD_LPC_REG_RESET_CAUSE_OFFSET	0x1d
> @@ -265,6 +266,7 @@
>  #define MLXPLAT_CPLD_LPC_LC_MASK	GENMASK(7, 0)
>  
>  #define MLXPLAT_CPLD_HALT_MASK		BIT(3)
> +#define MLXPLAT_CPLD_RESET_MASK		0xfe

GENMASK()

>  /* Default I2C parent bus number */
>  #define MLXPLAT_CPLD_PHYS_ADAPTER_DEF_NR	1
> @@ -441,6 +443,7 @@ static struct i2c_mux_reg_platform_data mlxplat_default_mux_data[] = {
>  static int mlxplat_max_adap_num;
>  static int mlxplat_mux_num;
>  static struct i2c_mux_reg_platform_data *mlxplat_mux_data;
> +static struct notifier_block *mlxplat_reboot_nb;
>  
>  /* Platform extended mux data */
>  static struct i2c_mux_reg_platform_data mlxplat_extended_mux_data[] = {
> @@ -2361,8 +2364,11 @@ static int
>  mlxplat_mlxcpld_l1_switch_pwr_events_handler(void *handle, enum mlxreg_hotplug_kind kind,
>  					     u8 action)
>  {
> -	dev_info(&mlxplat_dev->dev, "System shutdown due to short press of power button");
> -	kernel_power_off();
> +	if (action) {
> +		dev_info(&mlxplat_dev->dev, "System shutdown due to short press of power button");
> +		kernel_power_off();
> +	}
> +
>  	return 0;
>  }
>  
> @@ -4957,6 +4963,7 @@ static struct mlxreg_core_platform_data mlxplat_mlxcpld_wd_set_type3[] = {
>  static bool mlxplat_mlxcpld_writeable_reg(struct device *dev, unsigned int reg)
>  {
>  	switch (reg) {
> +	case MLXPLAT_CPLD_LPC_REG_RESET_GP1_OFFSET:
>  	case MLXPLAT_CPLD_LPC_REG_RESET_GP4_OFFSET:
>  	case MLXPLAT_CPLD_LPC_REG_LED1_OFFSET:
>  	case MLXPLAT_CPLD_LPC_REG_LED2_OFFSET:
> @@ -5065,6 +5072,7 @@ static bool mlxplat_mlxcpld_readable_reg(struct device *dev, unsigned int reg)
>  	case MLXPLAT_CPLD_LPC_REG_CPLD4_PN1_OFFSET:
>  	case MLXPLAT_CPLD_LPC_REG_CPLD5_PN_OFFSET:
>  	case MLXPLAT_CPLD_LPC_REG_CPLD5_PN1_OFFSET:
> +	case MLXPLAT_CPLD_LPC_REG_RESET_GP1_OFFSET:
>  	case MLXPLAT_CPLD_LPC_REG_RESET_GP4_OFFSET:
>  	case MLXPLAT_CPLD_LPC_REG_RESET_CAUSE_OFFSET:
>  	case MLXPLAT_CPLD_LPC_REG_RST_CAUSE1_OFFSET:
> @@ -5229,6 +5237,7 @@ static bool mlxplat_mlxcpld_volatile_reg(struct device *dev, unsigned int reg)
>  	case MLXPLAT_CPLD_LPC_REG_CPLD4_PN1_OFFSET:
>  	case MLXPLAT_CPLD_LPC_REG_CPLD5_PN_OFFSET:
>  	case MLXPLAT_CPLD_LPC_REG_CPLD5_PN1_OFFSET:
> +	case MLXPLAT_CPLD_LPC_REG_RESET_GP1_OFFSET:
>  	case MLXPLAT_CPLD_LPC_REG_RESET_GP4_OFFSET:
>  	case MLXPLAT_CPLD_LPC_REG_RESET_CAUSE_OFFSET:
>  	case MLXPLAT_CPLD_LPC_REG_RST_CAUSE1_OFFSET:
> @@ -5533,11 +5542,33 @@ static struct mlxreg_core_platform_data
>  	*mlxplat_wd_data[MLXPLAT_CPLD_WD_MAX_DEVS];
>  static const struct regmap_config *mlxplat_regmap_config;
>  
> +/* Platform default reset function */
> +static int mlxplat_reboot_notifier(struct notifier_block *nb, unsigned long action, void *unused)
> +{
> +	struct mlxplat_priv *priv = platform_get_drvdata(mlxplat_dev);
> +	u32 regval;
> +	int ret;
> +
> +	ret = regmap_read(priv->regmap, MLXPLAT_CPLD_LPC_REG_RESET_GP1_OFFSET, &regval);
> +
> +	if (action == SYS_RESTART && !ret && regval & BIT(0))

Use a named define instead of BIT(0) here.

-- 
 i.


> +		regmap_write(priv->regmap, MLXPLAT_CPLD_LPC_REG_RESET_GP1_OFFSET,
> +			     MLXPLAT_CPLD_RESET_MASK);
> +
> +	return NOTIFY_DONE;
> +}
> +
> +static struct notifier_block mlxplat_reboot_default_nb = {
> +	.notifier_call = mlxplat_reboot_notifier,
> +};
> +
>  /* Platform default poweroff function */
>  static void mlxplat_poweroff(void)
>  {
>  	struct mlxplat_priv *priv = platform_get_drvdata(mlxplat_dev);
>  
> +	if (mlxplat_reboot_nb)
> +		unregister_reboot_notifier(mlxplat_reboot_nb);
>  	regmap_write(priv->regmap, MLXPLAT_CPLD_LPC_REG_GP1_OFFSET, MLXPLAT_CPLD_HALT_MASK);
>  	kernel_halt();
>  }
> @@ -5861,6 +5892,7 @@ static int __init mlxplat_dmi_l1_switch_matched(const struct dmi_system_id *dmi)
>  	mlxplat_i2c = &mlxplat_mlxcpld_i2c_ng_data;
>  	mlxplat_regmap_config = &mlxplat_mlxcpld_regmap_config_rack_switch;
>  	pm_power_off = mlxplat_poweroff;
> +	mlxplat_reboot_nb = &mlxplat_reboot_default_nb;
>  
>  	return 1;
>  }
> @@ -6410,8 +6442,15 @@ static int __init mlxplat_init(void)
>  	if (err)
>  		goto fail_regcache_sync;
>  
> +	if (mlxplat_reboot_nb) {
> +		err = register_reboot_notifier(mlxplat_reboot_nb);
> +		if (err)
> +			goto fail_register_reboot_notifier;
> +	}
> +
>  	return 0;
>  
> +fail_register_reboot_notifier:
>  fail_regcache_sync:
>  	mlxplat_pre_exit(priv);
>  fail_mlxplat_i2c_main_init:
> @@ -6429,6 +6468,8 @@ static void __exit mlxplat_exit(void)
>  
>  	if (pm_power_off)
>  		pm_power_off = NULL;
> +	if (mlxplat_reboot_nb)
> +		unregister_reboot_notifier(mlxplat_reboot_nb);
>  	mlxplat_pre_exit(priv);
>  	mlxplat_i2c_main_exit(priv);
>  	mlxplat_post_exit();
>