/* * 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 BTEMP_PULL_UP 0x08 #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 * @chip_id ABB chip id * @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 { u8 chip_id; 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, ABB 3.0 needs some special * treatment too. */ 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; case BTEMP_BALL: if (gpadc->chip_id >= AB8500_CUT3P0) { /* Turn on btemp pull-up on ABB 3.0 */ ret = abx500_mask_and_set_register_interruptible( gpadc->dev, AB8500_GPADC, AB8500_GPADC_CTRL1_REG, EN_BUF | BTEMP_PULL_UP, EN_BUF | BTEMP_PULL_UP); /* * Delay might be needed for ABB8500 cut 3.0, if not, remove * when hardware will be availible */ msleep(1); break; } /* Intentional fallthrough */ 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: didn't receive 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; } /* Get Chip ID of the ABB ASIC */ ret = abx500_get_chip_id(gpadc->dev); if (ret < 0) { dev_err(gpadc->dev, "failed to get chip ID\n"); goto fail_irq; } gpadc->chip_id = (u8) ret; /* 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");