From 4071318983ff2dead7fd2caf85498bcd8956d93e Mon Sep 17 00:00:00 2001 From: Thara Gopinath Date: Tue, 15 Feb 2011 13:28:58 +0530 Subject: OMAP3: PM: Set/clear T2 bit for Smartreflex on TWL Voltage control on TWL can be done using VMODE/I2C1/I2C_SR. Since almost all platforms use I2C_SR on omap3, omap3_twl_init by default expects that OMAP's I2C_SR is plugged in to TWL's I2C and calls omap3_twl_set_sr_bit. On platforms where I2C_SR is not connected, the board files are expected to call omap3_twl_set_sr_bit(false) to ensure that I2C_SR path is not set for voltage control and prevent the default behavior of omap3_twl_init. Signed-off-by: Nishanth Menon Signed-off-by: Thara Gopinath Signed-off-by: Shweta Gulati Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Kevin Hilman --- arch/arm/mach-omap2/omap_twl.c | 60 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) (limited to 'arch/arm/mach-omap2/omap_twl.c') diff --git a/arch/arm/mach-omap2/omap_twl.c b/arch/arm/mach-omap2/omap_twl.c index 00e1d2b5368..b341c36a93f 100644 --- a/arch/arm/mach-omap2/omap_twl.c +++ b/arch/arm/mach-omap2/omap_twl.c @@ -59,8 +59,15 @@ static bool is_offset_valid; static u8 smps_offset; +/* + * Flag to ensure Smartreflex bit in TWL + * being cleared in board file is not overwritten. + */ +static bool __initdata twl_sr_enable_autoinit; +#define TWL4030_DCDC_GLOBAL_CFG 0x06 #define REG_SMPS_OFFSET 0xE0 +#define SMARTREFLEX_ENABLE BIT(3) static unsigned long twl4030_vsel_to_uv(const u8 vsel) { @@ -269,6 +276,18 @@ int __init omap3_twl_init(void) omap3_core_volt_info.vp_vddmax = OMAP3630_VP2_VLIMITTO_VDDMAX; } + /* + * The smartreflex bit on twl4030 specifies if the setting of voltage + * is done over the I2C_SR path. Since this setting is independent of + * the actual usage of smartreflex AVS module, we enable TWL SR bit + * by default irrespective of whether smartreflex AVS module is enabled + * on the OMAP side or not. This is because without this bit enabled, + * the voltage scaling through vp forceupdate/bypass mechanism of + * voltage scaling will not function on TWL over I2C_SR. + */ + if (!twl_sr_enable_autoinit) + omap3_twl_set_sr_bit(true); + voltdm = omap_voltage_domain_lookup("mpu"); omap_voltage_register_pmic(voltdm, &omap3_mpu_volt_info); @@ -277,3 +296,44 @@ int __init omap3_twl_init(void) return 0; } + +/** + * omap3_twl_set_sr_bit() - Set/Clear SR bit on TWL + * @enable: enable SR mode in twl or not + * + * If 'enable' is true, enables Smartreflex bit on TWL 4030 to make sure + * voltage scaling through OMAP SR works. Else, the smartreflex bit + * on twl4030 is cleared as there are platforms which use OMAP3 and T2 but + * use Synchronized Scaling Hardware Strategy (ENABLE_VMODE=1) and Direct + * Strategy Software Scaling Mode (ENABLE_VMODE=0), for setting the voltages, + * in those scenarios this bit is to be cleared (enable = false). + * + * Returns 0 on sucess, error is returned if I2C read/write fails. + */ +int __init omap3_twl_set_sr_bit(bool enable) +{ + u8 temp; + int ret; + if (twl_sr_enable_autoinit) + pr_warning("%s: unexpected multiple calls\n", __func__); + + ret = twl_i2c_read_u8(TWL4030_MODULE_PM_RECEIVER, &temp, + TWL4030_DCDC_GLOBAL_CFG); + if (ret) + goto err; + + if (enable) + temp |= SMARTREFLEX_ENABLE; + else + temp &= ~SMARTREFLEX_ENABLE; + + ret = twl_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, temp, + TWL4030_DCDC_GLOBAL_CFG); + if (!ret) { + twl_sr_enable_autoinit = true; + return 0; + } +err: + pr_err("%s: Error access to TWL4030 (%d)\n", __func__, ret); + return ret; +} -- cgit v1.2.3