diff options
Diffstat (limited to 'drivers/power/supply/ab8500_btemp.c')
| -rw-r--r-- | drivers/power/supply/ab8500_btemp.c | 103 |
1 files changed, 22 insertions, 81 deletions
diff --git a/drivers/power/supply/ab8500_btemp.c b/drivers/power/supply/ab8500_btemp.c index a5ca09124c93..2a6fc151210c 100644 --- a/drivers/power/supply/ab8500_btemp.c +++ b/drivers/power/supply/ab8500_btemp.c @@ -26,13 +26,12 @@ #include <linux/mfd/core.h> #include <linux/mfd/abx500.h> #include <linux/mfd/abx500/ab8500.h> +#include <linux/thermal.h> #include <linux/iio/consumer.h> #include <linux/fixp-arith.h> #include "ab8500-bm.h" -#define VTVOUT_V 1800 - #define BTEMP_THERMAL_LOW_LIMIT -10 #define BTEMP_THERMAL_MED_LIMIT 0 #define BTEMP_THERMAL_HIGH_LIMIT_52 52 @@ -82,7 +81,7 @@ struct ab8500_btemp_ranges { * @bat_temp: Dispatched battery temperature in degree Celsius * @prev_bat_temp Last measured battery temperature in degree Celsius * @parent: Pointer to the struct ab8500 - * @adc_btemp_ball: ADC channel for the battery ball temperature + * @tz: Thermal zone for the battery * @adc_bat_ctrl: ADC channel for the battery control * @fg: Pointer to the struct fg * @bm: Platform specific battery management information @@ -100,7 +99,7 @@ struct ab8500_btemp { int bat_temp; int prev_bat_temp; struct ab8500 *parent; - struct iio_channel *btemp_ball; + struct thermal_zone_device *tz; struct iio_channel *bat_ctrl; struct ab8500_fg *fg; struct ab8500_bm_data *bm; @@ -229,76 +228,6 @@ static int ab8500_btemp_get_batctrl_res(struct ab8500_btemp *di) } /** - * ab8500_btemp_res_to_temp() - resistance to temperature - * @di: pointer to the ab8500_btemp structure - * @tbl: pointer to the resiatance to temperature table - * @tbl_size: size of the resistance to temperature table - * @res: resistance to calculate the temperature from - * - * This function returns the battery temperature in degrees Celsius - * based on the NTC resistance. - */ -static int ab8500_btemp_res_to_temp(struct ab8500_btemp *di, - const struct ab8500_res_to_temp *tbl, int tbl_size, int res) -{ - int i; - /* - * Calculate the formula for the straight line - * Simple interpolation if we are within - * the resistance table limits, extrapolate - * if resistance is outside the limits. - */ - if (res > tbl[0].resist) - i = 0; - else if (res <= tbl[tbl_size - 1].resist) - i = tbl_size - 2; - else { - i = 0; - while (!(res <= tbl[i].resist && - res > tbl[i + 1].resist)) - i++; - } - - return fixp_linear_interpolate(tbl[i].resist, tbl[i].temp, - tbl[i + 1].resist, tbl[i + 1].temp, - res); -} - -/** - * ab8500_btemp_measure_temp() - measure battery temperature - * @di: pointer to the ab8500_btemp structure - * - * Returns battery temperature (on success) else the previous temperature - */ -static int ab8500_btemp_measure_temp(struct ab8500_btemp *di) -{ - int temp, ret; - static int prev; - int rntc, vntc; - - ret = iio_read_channel_processed(di->btemp_ball, &vntc); - if (ret < 0) { - dev_err(di->dev, - "%s ADC conversion failed," - " using previous value\n", __func__); - return prev; - } - /* - * The PCB NTC is sourced from VTVOUT via a 230kOhm - * resistor. - */ - rntc = 230000 * vntc / (VTVOUT_V - vntc); - - temp = ab8500_btemp_res_to_temp(di, - di->bm->bat_type->r_to_t_tbl, - di->bm->bat_type->n_temp_tbl_elements, rntc); - prev = temp; - - dev_dbg(di->dev, "Battery temperature is %d\n", temp); - return temp; -} - -/** * ab8500_btemp_id() - Identify the connected battery * @di: pointer to the ab8500_btemp structure * @@ -347,6 +276,9 @@ static void ab8500_btemp_periodic_work(struct work_struct *work) int bat_temp; struct ab8500_btemp *di = container_of(work, struct ab8500_btemp, btemp_periodic_work.work); + /* Assume 25 degrees celsius as start temperature */ + static int prev = 25; + int ret; if (!di->initialized) { /* Identify the battery */ @@ -354,7 +286,17 @@ static void ab8500_btemp_periodic_work(struct work_struct *work) dev_warn(di->dev, "failed to identify the battery\n"); } - bat_temp = ab8500_btemp_measure_temp(di); + /* Failover if a reading is erroneous, use last meausurement */ + ret = thermal_zone_get_temp(di->tz, &bat_temp); + if (ret) { + dev_err(di->dev, "error reading temperature\n"); + bat_temp = prev; + } else { + /* Convert from millicentigrades to centigrades */ + bat_temp /= 1000; + prev = bat_temp; + } + /* * Filter battery temperature. * Allow direct updates on temperature only if two samples result in @@ -783,12 +725,11 @@ static int ab8500_btemp_probe(struct platform_device *pdev) di->dev = dev; di->parent = dev_get_drvdata(pdev->dev.parent); - /* Get ADC channels */ - di->btemp_ball = devm_iio_channel_get(dev, "btemp_ball"); - if (IS_ERR(di->btemp_ball)) { - ret = dev_err_probe(dev, PTR_ERR(di->btemp_ball), - "failed to get BTEMP BALL ADC channel\n"); - return ret; + /* Get thermal zone and ADC */ + di->tz = thermal_zone_get_zone_by_name("battery-thermal"); + if (IS_ERR(di->tz)) { + return dev_err_probe(dev, PTR_ERR(di->tz), + "failed to get battery thermal zone\n"); } di->bat_ctrl = devm_iio_channel_get(dev, "bat_ctrl"); if (IS_ERR(di->bat_ctrl)) { |