Date: Mon, 10 Nov 2014 12:40:19 +0000
From: Lee Jones <lee.jones@linaro.org>
To: Tony Lindgren <tony@atomide.com>
Cc: Samuel Ortiz <sameo@linux.intel.com>,
        Russell King - ARM Linux <linux@arm.linux.org.uk>,
        linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org
Subject: Re: [PATCH] mfd: twl4030-power: Fix poweroff with PM configuration
 enabled
Message-ID: <20141110124019.GZ21424@x1>
References: <20141102180756.GH31454@atomide.com>
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On Sun, 02 Nov 2014, Tony Lindgren wrote:

> Commit e7cd1d1eb16f ("mfd: twl4030-power: Add generic reset
> configuration") enabled configuring the PM features for twl4030.
> 
> This caused poweroff command to fail on devices that have the
> BCI charger on twl4030 wired, or have power wired for VBUS.
> Instead of powering off, the device reboots. This is because
> voltage is detected on charger or VBUS with the default bits
> enabled for the power transition registers.
> 
> To fix the issue, let's just clear VBUS and CHG bits as we want
> poweroff command to keep the system powered off.
> 
> Fixes: e7cd1d1eb16f ("mfd: twl4030-power: Add generic reset configuration")
> Cc: stable@vger.kernel.org # v3.16+
> Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
> Signed-off-by: Tony Lindgren <tony@atomide.com>

Applied to -fixes.

Not sure whether that was an Ack from Russell or not?

> --- a/drivers/mfd/twl4030-power.c
> +++ b/drivers/mfd/twl4030-power.c
> @@ -44,6 +44,15 @@ static u8 twl4030_start_script_address = 0x2b;
>  #define PWR_DEVSLP		BIT(1)
>  #define PWR_DEVOFF		BIT(0)
>  
> +/* Register bits for CFG_P1_TRANSITION (also for P2 and P3) */
> +#define STARTON_SWBUG		BIT(7)	/* Start on watchdog */
> +#define STARTON_VBUS		BIT(5)	/* Start on VBUS */
> +#define STARTON_VBAT		BIT(4)	/* Start on battery insert */
> +#define STARTON_RTC		BIT(3)	/* Start on RTC */
> +#define STARTON_USB		BIT(2)	/* Start on USB host */
> +#define STARTON_CHG		BIT(1)	/* Start on charger */
> +#define STARTON_PWON		BIT(0)	/* Start on PWRON button */
> +
>  #define SEQ_OFFSYNC		(1 << 0)
>  
>  #define PHY_TO_OFF_PM_MASTER(p)		(p - 0x36)
> @@ -606,6 +615,44 @@ twl4030_power_configure_resources(const struct twl4030_power_data *pdata)
>  	return 0;
>  }
>  
> +static int twl4030_starton_mask_and_set(u8 bitmask, u8 bitvalues)
> +{
> +	u8 regs[3] = { TWL4030_PM_MASTER_CFG_P1_TRANSITION,
> +		       TWL4030_PM_MASTER_CFG_P2_TRANSITION,
> +		       TWL4030_PM_MASTER_CFG_P3_TRANSITION, };
> +	u8 val;
> +	int i, err;
> +
> +	err = twl_i2c_write_u8(TWL_MODULE_PM_MASTER, TWL4030_PM_MASTER_KEY_CFG1,
> +			       TWL4030_PM_MASTER_PROTECT_KEY);
> +	if (err)
> +		goto relock;
> +	err = twl_i2c_write_u8(TWL_MODULE_PM_MASTER,
> +			       TWL4030_PM_MASTER_KEY_CFG2,
> +			       TWL4030_PM_MASTER_PROTECT_KEY);
> +	if (err)
> +		goto relock;
> +
> +	for (i = 0; i < sizeof(regs); i++) {
> +		err = twl_i2c_read_u8(TWL_MODULE_PM_MASTER,
> +				      &val, regs[i]);
> +		if (err)
> +			break;
> +		val = (~bitmask & val) | (bitmask & bitvalues);
> +		err = twl_i2c_write_u8(TWL_MODULE_PM_MASTER,
> +				       val, regs[i]);
> +		if (err)
> +			break;
> +	}
> +
> +	if (err)
> +		pr_err("TWL4030 Register access failed: %i\n", err);
> +
> +relock:
> +	return twl_i2c_write_u8(TWL_MODULE_PM_MASTER, 0,
> +				TWL4030_PM_MASTER_PROTECT_KEY);
> +}
> +
>  /*
>   * In master mode, start the power off sequence.
>   * After a successful execution, TWL shuts down the power to the SoC
> @@ -615,6 +662,11 @@ void twl4030_power_off(void)
>  {
>  	int err;
>  
> +	/* Disable start on charger or VBUS as it can break poweroff */
> +	err = twl4030_starton_mask_and_set(STARTON_VBUS | STARTON_CHG, 0);
> +	if (err)
> +		pr_err("TWL4030 Unable to configure start-up\n");
> +
>  	err = twl_i2c_write_u8(TWL_MODULE_PM_MASTER, PWR_DEVOFF,
>  			       TWL4030_PM_MASTER_P1_SW_EVENTS);
>  	if (err)

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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