diff options
Diffstat (limited to 'drivers/mfd/ab8500-gpadc.c')
| -rw-r--r-- | drivers/mfd/ab8500-gpadc.c | 614 |
1 files changed, 614 insertions, 0 deletions
diff --git a/drivers/mfd/ab8500-gpadc.c b/drivers/mfd/ab8500-gpadc.c new file mode 100644 index 000000000000..bc93b2e8230c --- /dev/null +++ b/drivers/mfd/ab8500-gpadc.c @@ -0,0 +1,614 @@ +/* + * Copyright (C) ST-Ericsson SA 2010 + * + * License Terms: GNU General Public License v2 + * Author: Arun R Murthy <arun.murthy@stericsson.com> + * Author: Daniel Willerud <daniel.willerud@stericsson.com> + * Author: Johan Palsson <johan.palsson@stericsson.com> + */ +#include <linux/init.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/interrupt.h> +#include <linux/spinlock.h> +#include <linux/delay.h> +#include <linux/platform_device.h> +#include <linux/completion.h> +#include <linux/regulator/consumer.h> +#include <linux/err.h> +#include <linux/slab.h> +#include <linux/list.h> +#include <linux/mfd/ab8500.h> +#include <linux/mfd/abx500.h> +#include <linux/mfd/ab8500/gpadc.h> + +/* + * GPADC register offsets + * Bank : 0x0A + */ +#define AB8500_GPADC_CTRL1_REG 0x00 +#define AB8500_GPADC_CTRL2_REG 0x01 +#define AB8500_GPADC_CTRL3_REG 0x02 +#define AB8500_GPADC_AUTO_TIMER_REG 0x03 +#define AB8500_GPADC_STAT_REG 0x04 +#define AB8500_GPADC_MANDATAL_REG 0x05 +#define AB8500_GPADC_MANDATAH_REG 0x06 +#define AB8500_GPADC_AUTODATAL_REG 0x07 +#define AB8500_GPADC_AUTODATAH_REG 0x08 +#define AB8500_GPADC_MUX_CTRL_REG 0x09 + +/* + * OTP register offsets + * Bank : 0x15 + */ +#define AB8500_GPADC_CAL_1 0x0F +#define AB8500_GPADC_CAL_2 0x10 +#define AB8500_GPADC_CAL_3 0x11 +#define AB8500_GPADC_CAL_4 0x12 +#define AB8500_GPADC_CAL_5 0x13 +#define AB8500_GPADC_CAL_6 0x14 +#define AB8500_GPADC_CAL_7 0x15 + +/* gpadc constants */ +#define EN_VINTCORE12 0x04 +#define EN_VTVOUT 0x02 +#define EN_GPADC 0x01 +#define DIS_GPADC 0x00 +#define SW_AVG_16 0x60 +#define ADC_SW_CONV 0x04 +#define EN_ICHAR 0x80 +#define EN_BUF 0x40 +#define DIS_ZERO 0x00 +#define GPADC_BUSY 0x01 + +/* GPADC constants from AB8500 spec, UM0836 */ +#define ADC_RESOLUTION 1024 +#define ADC_CH_BTEMP_MIN 0 +#define ADC_CH_BTEMP_MAX 1350 +#define ADC_CH_DIETEMP_MIN 0 +#define ADC_CH_DIETEMP_MAX 1350 +#define ADC_CH_CHG_V_MIN 0 +#define ADC_CH_CHG_V_MAX 20030 +#define ADC_CH_ACCDET2_MIN 0 +#define ADC_CH_ACCDET2_MAX 2500 +#define ADC_CH_VBAT_MIN 2300 +#define ADC_CH_VBAT_MAX 4800 +#define ADC_CH_CHG_I_MIN 0 +#define ADC_CH_CHG_I_MAX 1500 +#define ADC_CH_BKBAT_MIN 0 +#define ADC_CH_BKBAT_MAX 3200 + +/* This is used to not lose precision when dividing to get gain and offset */ +#define CALIB_SCALE 1000 + +enum cal_channels { + ADC_INPUT_VMAIN = 0, + ADC_INPUT_BTEMP, + ADC_INPUT_VBAT, + NBR_CAL_INPUTS, +}; + +/** + * struct adc_cal_data - Table for storing gain and offset for the calibrated + * ADC channels + * @gain: Gain of the ADC channel + * @offset: Offset of the ADC channel + */ +struct adc_cal_data { + u64 gain; + u64 offset; +}; + +/** + * struct ab8500_gpadc - AB8500 GPADC device information + * @dev: pointer to the struct device + * @node: a list of AB8500 GPADCs, hence prepared for + reentrance + * @ab8500_gpadc_complete: pointer to the struct completion, to indicate + * the completion of gpadc conversion + * @ab8500_gpadc_lock: structure of type mutex + * @regu: pointer to the struct regulator + * @irq: interrupt number that is used by gpadc + * @cal_data array of ADC calibration data structs + */ +struct ab8500_gpadc { + struct device *dev; + struct list_head node; + struct completion ab8500_gpadc_complete; + struct mutex ab8500_gpadc_lock; + struct regulator *regu; + int irq; + struct adc_cal_data cal_data[NBR_CAL_INPUTS]; +}; + +static LIST_HEAD(ab8500_gpadc_list); + +/** + * ab8500_gpadc_get() - returns a reference to the primary AB8500 GPADC + * (i.e. the first GPADC in the instance list) + */ +struct ab8500_gpadc *ab8500_gpadc_get(char *name) +{ + struct ab8500_gpadc *gpadc; + + list_for_each_entry(gpadc, &ab8500_gpadc_list, node) { + if (!strcmp(name, dev_name(gpadc->dev))) + return gpadc; + } + + return ERR_PTR(-ENOENT); +} +EXPORT_SYMBOL(ab8500_gpadc_get); + +static int ab8500_gpadc_ad_to_voltage(struct ab8500_gpadc *gpadc, u8 input, + int ad_value) +{ + int res; + + switch (input) { + case MAIN_CHARGER_V: + /* For some reason we don't have calibrated data */ + if (!gpadc->cal_data[ADC_INPUT_VMAIN].gain) { + res = ADC_CH_CHG_V_MIN + (ADC_CH_CHG_V_MAX - + ADC_CH_CHG_V_MIN) * ad_value / + ADC_RESOLUTION; + break; + } + /* Here we can use the calibrated data */ + res = (int) (ad_value * gpadc->cal_data[ADC_INPUT_VMAIN].gain + + gpadc->cal_data[ADC_INPUT_VMAIN].offset) / CALIB_SCALE; + break; + + case BAT_CTRL: + case BTEMP_BALL: + case ACC_DETECT1: + case ADC_AUX1: + case ADC_AUX2: + /* For some reason we don't have calibrated data */ + if (!gpadc->cal_data[ADC_INPUT_BTEMP].gain) { + res = ADC_CH_BTEMP_MIN + (ADC_CH_BTEMP_MAX - + ADC_CH_BTEMP_MIN) * ad_value / + ADC_RESOLUTION; + break; + } + /* Here we can use the calibrated data */ + res = (int) (ad_value * gpadc->cal_data[ADC_INPUT_BTEMP].gain + + gpadc->cal_data[ADC_INPUT_BTEMP].offset) / CALIB_SCALE; + break; + + case MAIN_BAT_V: + /* For some reason we don't have calibrated data */ + if (!gpadc->cal_data[ADC_INPUT_VBAT].gain) { + res = ADC_CH_VBAT_MIN + (ADC_CH_VBAT_MAX - + ADC_CH_VBAT_MIN) * ad_value / + ADC_RESOLUTION; + break; + } + /* Here we can use the calibrated data */ + res = (int) (ad_value * gpadc->cal_data[ADC_INPUT_VBAT].gain + + gpadc->cal_data[ADC_INPUT_VBAT].offset) / CALIB_SCALE; + break; + + case DIE_TEMP: + res = ADC_CH_DIETEMP_MIN + + (ADC_CH_DIETEMP_MAX - ADC_CH_DIETEMP_MIN) * ad_value / + ADC_RESOLUTION; + break; + + case ACC_DETECT2: + res = ADC_CH_ACCDET2_MIN + + (ADC_CH_ACCDET2_MAX - ADC_CH_ACCDET2_MIN) * ad_value / + ADC_RESOLUTION; + break; + + case VBUS_V: + res = ADC_CH_CHG_V_MIN + + (ADC_CH_CHG_V_MAX - ADC_CH_CHG_V_MIN) * ad_value / + ADC_RESOLUTION; + break; + + case MAIN_CHARGER_C: + case USB_CHARGER_C: + res = ADC_CH_CHG_I_MIN + + (ADC_CH_CHG_I_MAX - ADC_CH_CHG_I_MIN) * ad_value / + ADC_RESOLUTION; + break; + + case BK_BAT_V: + res = ADC_CH_BKBAT_MIN + + (ADC_CH_BKBAT_MAX - ADC_CH_BKBAT_MIN) * ad_value / + ADC_RESOLUTION; + break; + + default: + dev_err(gpadc->dev, + "unknown channel, not possible to convert\n"); + res = -EINVAL; + break; + + } + return res; +} + +/** + * ab8500_gpadc_convert() - gpadc conversion + * @input: analog input to be converted to digital data + * + * This function converts the selected analog i/p to digital + * data. + */ +int ab8500_gpadc_convert(struct ab8500_gpadc *gpadc, u8 input) +{ + int ret; + u16 data = 0; + int looplimit = 0; + u8 val, low_data, high_data; + + if (!gpadc) + return -ENODEV; + + mutex_lock(&gpadc->ab8500_gpadc_lock); + /* Enable VTVout LDO this is required for GPADC */ + regulator_enable(gpadc->regu); + + /* Check if ADC is not busy, lock and proceed */ + do { + ret = abx500_get_register_interruptible(gpadc->dev, + AB8500_GPADC, AB8500_GPADC_STAT_REG, &val); + if (ret < 0) + goto out; + if (!(val & GPADC_BUSY)) + break; + msleep(10); + } while (++looplimit < 10); + if (looplimit >= 10 && (val & GPADC_BUSY)) { + dev_err(gpadc->dev, "gpadc_conversion: GPADC busy"); + ret = -EINVAL; + goto out; + } + + /* Enable GPADC */ + ret = abx500_mask_and_set_register_interruptible(gpadc->dev, + AB8500_GPADC, AB8500_GPADC_CTRL1_REG, EN_GPADC, EN_GPADC); + if (ret < 0) { + dev_err(gpadc->dev, "gpadc_conversion: enable gpadc failed\n"); + goto out; + } + /* Select the input source and set average samples to 16 */ + ret = abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC, + AB8500_GPADC_CTRL2_REG, (input | SW_AVG_16)); + if (ret < 0) { + dev_err(gpadc->dev, + "gpadc_conversion: set avg samples failed\n"); + goto out; + } + /* + * Enable ADC, buffering, select rising edge and enable ADC path + * charging current sense if it needed + */ + switch (input) { + case MAIN_CHARGER_C: + case USB_CHARGER_C: + ret = abx500_mask_and_set_register_interruptible(gpadc->dev, + AB8500_GPADC, AB8500_GPADC_CTRL1_REG, + EN_BUF | EN_ICHAR, + EN_BUF | EN_ICHAR); + break; + default: + ret = abx500_mask_and_set_register_interruptible(gpadc->dev, + AB8500_GPADC, AB8500_GPADC_CTRL1_REG, EN_BUF, EN_BUF); + break; + } + if (ret < 0) { + dev_err(gpadc->dev, + "gpadc_conversion: select falling edge failed\n"); + goto out; + } + ret = abx500_mask_and_set_register_interruptible(gpadc->dev, + AB8500_GPADC, AB8500_GPADC_CTRL1_REG, ADC_SW_CONV, ADC_SW_CONV); + if (ret < 0) { + dev_err(gpadc->dev, + "gpadc_conversion: start s/w conversion failed\n"); + goto out; + } + /* wait for completion of conversion */ + if (!wait_for_completion_timeout(&gpadc->ab8500_gpadc_complete, 2*HZ)) { + dev_err(gpadc->dev, + "timeout: didnt recieve GPADC conversion interrupt\n"); + ret = -EINVAL; + goto out; + } + + /* Read the converted RAW data */ + ret = abx500_get_register_interruptible(gpadc->dev, AB8500_GPADC, + AB8500_GPADC_MANDATAL_REG, &low_data); + if (ret < 0) { + dev_err(gpadc->dev, "gpadc_conversion: read low data failed\n"); + goto out; + } + + ret = abx500_get_register_interruptible(gpadc->dev, AB8500_GPADC, + AB8500_GPADC_MANDATAH_REG, &high_data); + if (ret < 0) { + dev_err(gpadc->dev, + "gpadc_conversion: read high data failed\n"); + goto out; + } + + data = (high_data << 8) | low_data; + /* Disable GPADC */ + ret = abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC, + AB8500_GPADC_CTRL1_REG, DIS_GPADC); + if (ret < 0) { + dev_err(gpadc->dev, "gpadc_conversion: disable gpadc failed\n"); + goto out; + } + /* Disable VTVout LDO this is required for GPADC */ + regulator_disable(gpadc->regu); + mutex_unlock(&gpadc->ab8500_gpadc_lock); + ret = ab8500_gpadc_ad_to_voltage(gpadc, input, data); + return ret; + +out: + /* + * It has shown to be needed to turn off the GPADC if an error occurs, + * otherwise we might have problem when waiting for the busy bit in the + * GPADC status register to go low. In V1.1 there wait_for_completion + * seems to timeout when waiting for an interrupt.. Not seen in V2.0 + */ + (void) abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC, + AB8500_GPADC_CTRL1_REG, DIS_GPADC); + regulator_disable(gpadc->regu); + mutex_unlock(&gpadc->ab8500_gpadc_lock); + dev_err(gpadc->dev, + "gpadc_conversion: Failed to AD convert channel %d\n", input); + return ret; +} +EXPORT_SYMBOL(ab8500_gpadc_convert); + +/** + * ab8500_bm_gpswadcconvend_handler() - isr for s/w gpadc conversion completion + * @irq: irq number + * @data: pointer to the data passed during request irq + * + * This is a interrupt service routine for s/w gpadc conversion completion. + * Notifies the gpadc completion is completed and the converted raw value + * can be read from the registers. + * Returns IRQ status(IRQ_HANDLED) + */ +static irqreturn_t ab8500_bm_gpswadcconvend_handler(int irq, void *_gpadc) +{ + struct ab8500_gpadc *gpadc = _gpadc; + + complete(&gpadc->ab8500_gpadc_complete); + + return IRQ_HANDLED; +} + +static int otp_cal_regs[] = { + AB8500_GPADC_CAL_1, + AB8500_GPADC_CAL_2, + AB8500_GPADC_CAL_3, + AB8500_GPADC_CAL_4, + AB8500_GPADC_CAL_5, + AB8500_GPADC_CAL_6, + AB8500_GPADC_CAL_7, +}; + +static void ab8500_gpadc_read_calibration_data(struct ab8500_gpadc *gpadc) +{ + int i; + int ret[ARRAY_SIZE(otp_cal_regs)]; + u8 gpadc_cal[ARRAY_SIZE(otp_cal_regs)]; + + int vmain_high, vmain_low; + int btemp_high, btemp_low; + int vbat_high, vbat_low; + + /* First we read all OTP registers and store the error code */ + for (i = 0; i < ARRAY_SIZE(otp_cal_regs); i++) { + ret[i] = abx500_get_register_interruptible(gpadc->dev, + AB8500_OTP_EMUL, otp_cal_regs[i], &gpadc_cal[i]); + if (ret[i] < 0) + dev_err(gpadc->dev, "%s: read otp reg 0x%02x failed\n", + __func__, otp_cal_regs[i]); + } + + /* + * The ADC calibration data is stored in OTP registers. + * The layout of the calibration data is outlined below and a more + * detailed description can be found in UM0836 + * + * vm_h/l = vmain_high/low + * bt_h/l = btemp_high/low + * vb_h/l = vbat_high/low + * + * Data bits: + * | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 + * |.......|.......|.......|.......|.......|.......|.......|....... + * | | vm_h9 | vm_h8 + * |.......|.......|.......|.......|.......|.......|.......|....... + * | | vm_h7 | vm_h6 | vm_h5 | vm_h4 | vm_h3 | vm_h2 + * |.......|.......|.......|.......|.......|.......|.......|....... + * | vm_h1 | vm_h0 | vm_l4 | vm_l3 | vm_l2 | vm_l1 | vm_l0 | bt_h9 + * |.......|.......|.......|.......|.......|.......|.......|....... + * | bt_h8 | bt_h7 | bt_h6 | bt_h5 | bt_h4 | bt_h3 | bt_h2 | bt_h1 + * |.......|.......|.......|.......|.......|.......|.......|....... + * | bt_h0 | bt_l4 | bt_l3 | bt_l2 | bt_l1 | bt_l0 | vb_h9 | vb_h8 + * |.......|.......|.......|.......|.......|.......|.......|....... + * | vb_h7 | vb_h6 | vb_h5 | vb_h4 | vb_h3 | vb_h2 | vb_h1 | vb_h0 + * |.......|.......|.......|.......|.......|.......|.......|....... + * | vb_l5 | vb_l4 | vb_l3 | vb_l2 | vb_l1 | vb_l0 | + * |.......|.......|.......|.......|.......|.......|.......|....... + * + * + * Ideal output ADC codes corresponding to injected input voltages + * during manufacturing is: + * + * vmain_high: Vin = 19500mV / ADC ideal code = 997 + * vmain_low: Vin = 315mV / ADC ideal code = 16 + * btemp_high: Vin = 1300mV / ADC ideal code = 985 + * btemp_low: Vin = 21mV / ADC ideal code = 16 + * vbat_high: Vin = 4700mV / ADC ideal code = 982 + * vbat_low: Vin = 2380mV / ADC ideal code = 33 + */ + + /* Calculate gain and offset for VMAIN if all reads succeeded */ + if (!(ret[0] < 0 || ret[1] < 0 || ret[2] < 0)) { + vmain_high = (((gpadc_cal[0] & 0x03) << 8) | + ((gpadc_cal[1] & 0x3F) << 2) | + ((gpadc_cal[2] & 0xC0) >> 6)); + + vmain_low = ((gpadc_cal[2] & 0x3E) >> 1); + + gpadc->cal_data[ADC_INPUT_VMAIN].gain = CALIB_SCALE * + (19500 - 315) / (vmain_high - vmain_low); + + gpadc->cal_data[ADC_INPUT_VMAIN].offset = CALIB_SCALE * 19500 - + (CALIB_SCALE * (19500 - 315) / + (vmain_high - vmain_low)) * vmain_high; + } else { + gpadc->cal_data[ADC_INPUT_VMAIN].gain = 0; + } + + /* Calculate gain and offset for BTEMP if all reads succeeded */ + if (!(ret[2] < 0 || ret[3] < 0 || ret[4] < 0)) { + btemp_high = (((gpadc_cal[2] & 0x01) << 9) | + (gpadc_cal[3] << 1) | + ((gpadc_cal[4] & 0x80) >> 7)); + + btemp_low = ((gpadc_cal[4] & 0x7C) >> 2); + + gpadc->cal_data[ADC_INPUT_BTEMP].gain = + CALIB_SCALE * (1300 - 21) / (btemp_high - btemp_low); + + gpadc->cal_data[ADC_INPUT_BTEMP].offset = CALIB_SCALE * 1300 - + (CALIB_SCALE * (1300 - 21) / + (btemp_high - btemp_low)) * btemp_high; + } else { + gpadc->cal_data[ADC_INPUT_BTEMP].gain = 0; + } + + /* Calculate gain and offset for VBAT if all reads succeeded */ + if (!(ret[4] < 0 || ret[5] < 0 || ret[6] < 0)) { + vbat_high = (((gpadc_cal[4] & 0x03) << 8) | gpadc_cal[5]); + vbat_low = ((gpadc_cal[6] & 0xFC) >> 2); + + gpadc->cal_data[ADC_INPUT_VBAT].gain = CALIB_SCALE * + (4700 - 2380) / (vbat_high - vbat_low); + + gpadc->cal_data[ADC_INPUT_VBAT].offset = CALIB_SCALE * 4700 - + (CALIB_SCALE * (4700 - 2380) / + (vbat_high - vbat_low)) * vbat_high; + } else { + gpadc->cal_data[ADC_INPUT_VBAT].gain = 0; + } + + dev_dbg(gpadc->dev, "VMAIN gain %llu offset %llu\n", + gpadc->cal_data[ADC_INPUT_VMAIN].gain, + gpadc->cal_data[ADC_INPUT_VMAIN].offset); + + dev_dbg(gpadc->dev, "BTEMP gain %llu offset %llu\n", + gpadc->cal_data[ADC_INPUT_BTEMP].gain, + gpadc->cal_data[ADC_INPUT_BTEMP].offset); + + dev_dbg(gpadc->dev, "VBAT gain %llu offset %llu\n", + gpadc->cal_data[ADC_INPUT_VBAT].gain, + gpadc->cal_data[ADC_INPUT_VBAT].offset); +} + +static int __devinit ab8500_gpadc_probe(struct platform_device *pdev) +{ + int ret = 0; + struct ab8500_gpadc *gpadc; + + gpadc = kzalloc(sizeof(struct ab8500_gpadc), GFP_KERNEL); + if (!gpadc) { + dev_err(&pdev->dev, "Error: No memory\n"); + return -ENOMEM; + } + + gpadc->irq = platform_get_irq_byname(pdev, "SW_CONV_END"); + if (gpadc->irq < 0) { + dev_err(gpadc->dev, "failed to get platform irq-%d\n", + gpadc->irq); + ret = gpadc->irq; + goto fail; + } + + gpadc->dev = &pdev->dev; + mutex_init(&gpadc->ab8500_gpadc_lock); + + /* Initialize completion used to notify completion of conversion */ + init_completion(&gpadc->ab8500_gpadc_complete); + + /* Register interrupt - SwAdcComplete */ + ret = request_threaded_irq(gpadc->irq, NULL, + ab8500_bm_gpswadcconvend_handler, + IRQF_NO_SUSPEND | IRQF_SHARED, "ab8500-gpadc", gpadc); + if (ret < 0) { + dev_err(gpadc->dev, "Failed to register interrupt, irq: %d\n", + gpadc->irq); + goto fail; + } + + /* VTVout LDO used to power up ab8500-GPADC */ + gpadc->regu = regulator_get(&pdev->dev, "vddadc"); + if (IS_ERR(gpadc->regu)) { + ret = PTR_ERR(gpadc->regu); + dev_err(gpadc->dev, "failed to get vtvout LDO\n"); + goto fail_irq; + } + ab8500_gpadc_read_calibration_data(gpadc); + list_add_tail(&gpadc->node, &ab8500_gpadc_list); + dev_dbg(gpadc->dev, "probe success\n"); + return 0; +fail_irq: + free_irq(gpadc->irq, gpadc); +fail: + kfree(gpadc); + gpadc = NULL; + return ret; +} + +static int __devexit ab8500_gpadc_remove(struct platform_device *pdev) +{ + struct ab8500_gpadc *gpadc = platform_get_drvdata(pdev); + + /* remove this gpadc entry from the list */ + list_del(&gpadc->node); + /* remove interrupt - completion of Sw ADC conversion */ + free_irq(gpadc->irq, gpadc); + /* disable VTVout LDO that is being used by GPADC */ + regulator_put(gpadc->regu); + kfree(gpadc); + gpadc = NULL; + return 0; +} + +static struct platform_driver ab8500_gpadc_driver = { + .probe = ab8500_gpadc_probe, + .remove = __devexit_p(ab8500_gpadc_remove), + .driver = { + .name = "ab8500-gpadc", + .owner = THIS_MODULE, + }, +}; + +static int __init ab8500_gpadc_init(void) +{ + return platform_driver_register(&ab8500_gpadc_driver); +} + +static void __exit ab8500_gpadc_exit(void) +{ + platform_driver_unregister(&ab8500_gpadc_driver); +} + +subsys_initcall_sync(ab8500_gpadc_init); +module_exit(ab8500_gpadc_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Arun R Murthy, Daniel Willerud, Johan Palsson"); +MODULE_ALIAS("platform:ab8500_gpadc"); +MODULE_DESCRIPTION("AB8500 GPADC driver"); |