linux-kernel - Re: [PATCH] MFD: TWL: add power off functionality

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Date:	Sun, 27 Nov 2011 11:42:17 +0200
From:	Igor Grinberg <grinberg@...pulab.co.il>
To:	Igor Grinberg <grinberg@...pulab.co.il>
CC:	Samuel Ortiz <sameo@...ux.intel.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] MFD: TWL: add power off functionality

ping!


On 11/13/11 11:49, Igor Grinberg wrote:
> TWL family of PMICs, used in master mode, have a power off
> functionality. The resulting power off sequence shuts down all the SoC
> supplies, LDOs, etc. The sequence is described in the datasheets
> chapter "Power-Off Sequence".
> Note, that board must be wired correctly for the power off to work as
> expected.
> 
> Signed-off-by: Igor Grinberg <grinberg@...pulab.co.il>
> ---
>  drivers/mfd/twl4030-power.c |   42 ++++++++++++++++++++++++++++++++++++++++--
>  include/linux/i2c/twl.h     |    2 ++
>  2 files changed, 42 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mfd/twl4030-power.c b/drivers/mfd/twl4030-power.c
> index a764676..d905f51 100644
> --- a/drivers/mfd/twl4030-power.c
> +++ b/drivers/mfd/twl4030-power.c
> @@ -34,7 +34,8 @@
>  static u8 twl4030_start_script_address = 0x2b;
>  
>  #define PWR_P1_SW_EVENTS	0x10
> -#define PWR_DEVOFF	(1<<0)
> +#define PWR_DEVOFF		(1 << 0)
> +#define SEQ_OFFSYNC		(1 << 0)
>  
>  #define PHY_TO_OFF_PM_MASTER(p)		(p - 0x36)
>  #define PHY_TO_OFF_PM_RECEIVER(p)	(p - 0x5b)
> @@ -511,12 +512,27 @@ int twl4030_remove_script(u8 flags)
>  	return err;
>  }
>  
> +/*
> + * In master mode, start the power off sequence.
> + * After a successful execution, TWL shuts down the power to the SoC
> + * and all peripherals connected to it.
> + */
> +void twl4030_power_off(void)
> +{
> +	int err;
> +
> +	err = twl_i2c_write_u8(TWL4030_MODULE_PM_MASTER, PWR_DEVOFF,
> +			       TWL4030_PM_MASTER_P1_SW_EVENTS);
> +	if (err)
> +		pr_err("TWL4030 Unable to power off\n");
> +}
> +
>  void __init twl4030_power_init(struct twl4030_power_data *twl4030_scripts)
>  {
>  	int err = 0;
>  	int i;
>  	struct twl4030_resconfig *resconfig;
> -	u8 address = twl4030_start_script_address;
> +	u8 val, address = twl4030_start_script_address;
>  
>  	err = twl_i2c_write_u8(TWL4030_MODULE_PM_MASTER,
>  			TWL4030_PM_MASTER_KEY_CFG1,
> @@ -548,6 +564,28 @@ void __init twl4030_power_init(struct twl4030_power_data *twl4030_scripts)
>  		}
>  	}
>  
> +	/* Board has to be wired properly to use this feature */
> +	if (twl4030_scripts->use_poweroff && !pm_power_off) {
> +		/* Default for SEQ_OFFSYNC is set, lets ensure this */
> +		err = twl_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &val,
> +				      TWL4030_PM_MASTER_CFG_P123_TRANSITION);
> +		if (err) {
> +			pr_warning("TWL4030 Unable to read registers\n");
> +
> +		} else if (!(val & SEQ_OFFSYNC)) {
> +			val |= SEQ_OFFSYNC;
> +			err = twl_i2c_write_u8(TWL4030_MODULE_PM_MASTER, val,
> +					TWL4030_PM_MASTER_CFG_P123_TRANSITION);
> +			if (err) {
> +				pr_err("TWL4030 Unable to setup SEQ_OFFSYNC\n");
> +				goto relock;
> +			}
> +		}
> +
> +		pm_power_off = twl4030_power_off;
> +	}
> +
> +relock:
>  	err = twl_i2c_write_u8(TWL4030_MODULE_PM_MASTER, 0,
>  			TWL4030_PM_MASTER_PROTECT_KEY);
>  	if (err)
> diff --git a/include/linux/i2c/twl.h b/include/linux/i2c/twl.h
> index 114c0f6..78d3465 100644
> --- a/include/linux/i2c/twl.h
> +++ b/include/linux/i2c/twl.h
> @@ -652,10 +652,12 @@ struct twl4030_power_data {
>  	unsigned num;
>  	struct twl4030_resconfig *resource_config;
>  #define TWL4030_RESCONFIG_UNDEF	((u8)-1)
> +	bool use_poweroff;	/* Board is wired for TWL poweroff */
>  };
>  
>  extern void twl4030_power_init(struct twl4030_power_data *triton2_scripts);
>  extern int twl4030_remove_script(u8 flags);
> +extern void twl4030_power_off(void);
>  
>  struct twl4030_codec_data {
>  	unsigned int digimic_delay; /* in ms */

-- 
Regards,
Igor.
--
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