From f8e96dff240982c1433d447bae533acc36b5cf8f Mon Sep 17 00:00:00 2001 From: Johan Bjornstedt Date: Wed, 18 Jan 2012 12:44:55 +0100 Subject: [PATCH] ab8500_charger: Charger current step-up/down There is no state machine in the AB to step up/down the charger current to avoid dips and spikes on VBUS and VBAT when charging is started. Instead this is implemented in SW. Signed-off-by: Johan Bjornstedt Signed-off-by: Mattias Wallin Signed-off-by: Lee Jones Reviewed-by: Karl KOMIEROWSKI --- drivers/power/ab8500_charger.c | 175 +++++++++++++++++++++++++-------- 1 file changed, 135 insertions(+), 40 deletions(-) diff --git a/drivers/power/ab8500_charger.c b/drivers/power/ab8500_charger.c index dddc9473f72a..d27dd7fec163 100644 --- a/drivers/power/ab8500_charger.c +++ b/drivers/power/ab8500_charger.c @@ -79,6 +79,9 @@ /* Lowest charger voltage is 3.39V -> 0x4E */ #define LOW_VOLT_REG 0x4E +/* Step up/down delay in us */ +#define STEP_UDELAY 1000 + /* UsbLineStatus register - usb types */ enum ab8500_charger_link_status { USB_STAT_NOT_CONFIGURED, @@ -935,6 +938,88 @@ static int ab8500_charger_get_usb_cur(struct ab8500_charger *di) return 0; } +/** + * ab8500_charger_set_current() - set charger current + * @di: pointer to the ab8500_charger structure + * @ich: charger current, in mA + * @reg: select what charger register to set + * + * Set charger current. + * There is no state machine in the AB to step up/down the charger + * current to avoid dips and spikes on MAIN, VBUS and VBAT when + * charging is started. Instead we need to implement + * this charger current step-up/down here. + * Returns error code in case of failure else 0(on success) + */ +static int ab8500_charger_set_current(struct ab8500_charger *di, + int ich, int reg) +{ + int ret, i; + int curr_index, prev_curr_index, shift_value; + u8 reg_value; + + switch (reg) { + case AB8500_MCH_IPT_CURLVL_REG: + shift_value = MAIN_CH_INPUT_CURR_SHIFT; + curr_index = ab8500_current_to_regval(ich); + break; + case AB8500_USBCH_IPT_CRNTLVL_REG: + shift_value = VBUS_IN_CURR_LIM_SHIFT; + curr_index = ab8500_vbus_in_curr_to_regval(ich); + break; + case AB8500_CH_OPT_CRNTLVL_REG: + shift_value = 0; + curr_index = ab8500_current_to_regval(ich); + break; + default: + dev_err(di->dev, "%s current register not valid\n", __func__); + return -ENXIO; + } + + if (curr_index < 0) { + dev_err(di->dev, "requested current limit out-of-range\n"); + return -ENXIO; + } + + ret = abx500_get_register_interruptible(di->dev, AB8500_CHARGER, + reg, ®_value); + if (ret < 0) { + dev_err(di->dev, "%s read failed\n", __func__); + return ret; + } + prev_curr_index = (reg_value >> shift_value); + + /* only update current if it's been changed */ + if (prev_curr_index == curr_index) + return 0; + + dev_dbg(di->dev, "%s set charger current: %d mA for reg: 0x%02x\n", + __func__, ich, reg); + + if (prev_curr_index > curr_index) { + for (i = prev_curr_index - 1; i >= curr_index; i--) { + ret = abx500_set_register_interruptible(di->dev, + AB8500_CHARGER, reg, (u8) i << shift_value); + if (ret) { + dev_err(di->dev, "%s write failed\n", __func__); + return ret; + } + usleep_range(STEP_UDELAY, STEP_UDELAY * 2); + } + } else { + for (i = prev_curr_index + 1; i <= curr_index; i++) { + ret = abx500_set_register_interruptible(di->dev, + AB8500_CHARGER, reg, (u8) i << shift_value); + if (ret) { + dev_err(di->dev, "%s write failed\n", __func__); + return ret; + } + usleep_range(STEP_UDELAY, STEP_UDELAY * 2); + } + } + return ret; +} + /** * ab8500_charger_set_vbus_in_curr() - set VBUS input current limit * @di: pointer to the ab8500_charger structure @@ -946,8 +1031,6 @@ static int ab8500_charger_get_usb_cur(struct ab8500_charger *di) static int ab8500_charger_set_vbus_in_curr(struct ab8500_charger *di, int ich_in) { - int ret; - int input_curr_index; int min_value; /* We should always use to lowest current limit */ @@ -966,19 +1049,38 @@ static int ab8500_charger_set_vbus_in_curr(struct ab8500_charger *di, break; } - input_curr_index = ab8500_vbus_in_curr_to_regval(min_value); - if (input_curr_index < 0) { - dev_err(di->dev, "VBUS input current limit too high\n"); - return -ENXIO; - } + return ab8500_charger_set_current(di, min_value, + AB8500_USBCH_IPT_CRNTLVL_REG); +} - ret = abx500_set_register_interruptible(di->dev, AB8500_CHARGER, - AB8500_USBCH_IPT_CRNTLVL_REG, - input_curr_index << VBUS_IN_CURR_LIM_SHIFT); - if (ret) - dev_err(di->dev, "%s write failed\n", __func__); +/** + * ab8500_charger_set_main_in_curr() - set main charger input current + * @di: pointer to the ab8500_charger structure + * @ich_in: input charger current, in mA + * + * Set main charger input current. + * Returns error code in case of failure else 0(on success) + */ +static int ab8500_charger_set_main_in_curr(struct ab8500_charger *di, + int ich_in) +{ + return ab8500_charger_set_current(di, ich_in, + AB8500_MCH_IPT_CURLVL_REG); +} - return ret; +/** + * ab8500_charger_set_output_curr() - set charger output current + * @di: pointer to the ab8500_charger structure + * @ich_out: output charger current, in mA + * + * Set charger output current. + * Returns error code in case of failure else 0(on success) + */ +static int ab8500_charger_set_output_curr(struct ab8500_charger *di, + int ich_out) +{ + return ab8500_charger_set_current(di, ich_out, + AB8500_CH_OPT_CRNTLVL_REG); } /** @@ -1090,18 +1192,19 @@ static int ab8500_charger_ac_en(struct ux500_charger *charger, return ret; } /* MainChInputCurr: current that can be drawn from the charger*/ - ret = abx500_set_register_interruptible(di->dev, AB8500_CHARGER, - AB8500_MCH_IPT_CURLVL_REG, - input_curr_index << MAIN_CH_INPUT_CURR_SHIFT); + ret = ab8500_charger_set_main_in_curr(di, + di->bat->chg_params->ac_curr_max); if (ret) { - dev_err(di->dev, "%s write failed\n", __func__); + dev_err(di->dev, "%s Failed to set MainChInputCurr\n", + __func__); return ret; } /* ChOutputCurentLevel: protected output current */ - ret = abx500_set_register_interruptible(di->dev, AB8500_CHARGER, - AB8500_CH_OPT_CRNTLVL_REG, (u8) curr_index); + ret = ab8500_charger_set_output_curr(di, iset); if (ret) { - dev_err(di->dev, "%s write failed\n", __func__); + dev_err(di->dev, "%s " + "Failed to set ChOutputCurentLevel\n", + __func__); return ret; } @@ -1158,12 +1261,11 @@ static int ab8500_charger_ac_en(struct ux500_charger *charger, return ret; } - ret = abx500_set_register_interruptible(di->dev, - AB8500_CHARGER, - AB8500_CH_OPT_CRNTLVL_REG, CH_OP_CUR_LVL_0P1); + ret = ab8500_charger_set_output_curr(di, 0); if (ret) { - dev_err(di->dev, - "%s write failed\n", __func__); + dev_err(di->dev, "%s " + "Failed to set ChOutputCurentLevel\n", + __func__); return ret; } } else { @@ -1266,10 +1368,11 @@ static int ab8500_charger_usb_en(struct ux500_charger *charger, return ret; } /* ChOutputCurentLevel: protected output current */ - ret = abx500_set_register_interruptible(di->dev, AB8500_CHARGER, - AB8500_CH_OPT_CRNTLVL_REG, (u8) curr_index); + ret = ab8500_charger_set_output_curr(di, ich_out); if (ret) { - dev_err(di->dev, "%s write failed\n", __func__); + dev_err(di->dev, "%s " + "Failed to set ChOutputCurentLevel\n", + __func__); return ret; } /* Check if VBAT overshoot control should be enabled */ @@ -1366,7 +1469,6 @@ static int ab8500_charger_update_charger_current(struct ux500_charger *charger, int ich_out) { int ret; - int curr_index; struct ab8500_charger *di; if (charger->psy.type == POWER_SUPPLY_TYPE_MAINS) @@ -1376,18 +1478,11 @@ static int ab8500_charger_update_charger_current(struct ux500_charger *charger, else return -ENXIO; - curr_index = ab8500_current_to_regval(ich_out); - if (curr_index < 0) { - dev_err(di->dev, - "Charger current too high, " - "charging not started\n"); - return -ENXIO; - } - - ret = abx500_set_register_interruptible(di->dev, AB8500_CHARGER, - AB8500_CH_OPT_CRNTLVL_REG, (u8) curr_index); + ret = ab8500_charger_set_output_curr(di, ich_out); if (ret) { - dev_err(di->dev, "%s write failed\n", __func__); + dev_err(di->dev, "%s " + "Failed to set ChOutputCurentLevel\n", + __func__); return ret; }