/* * * TWL4030 MADC module driver-This driver monitors the real time * conversion of analog signals like battery temperature, * battery type, battery level etc. * * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/ * J Keerthy * * Based on twl4030-madc.c * Copyright (C) 2008 Nokia Corporation * Mikko Ylinen * * Amit Kucheria * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * version 2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * struct twl4030_madc_data - a container for madc info * @dev - pointer to device structure for madc * @lock - mutex protecting this data structure * @requests - Array of request struct corresponding to SW1, SW2 and RT * @imr - Interrupt mask register of MADC * @isr - Interrupt status register of MADC */ struct twl4030_madc_data { struct device *dev; struct mutex lock; /* mutex protecting this data structure */ struct twl4030_madc_request requests[TWL4030_MADC_NUM_METHODS]; int imr; int isr; }; static struct twl4030_madc_data *twl4030_madc; struct twl4030_prescale_divider_ratios { s16 numerator; s16 denominator; }; static const struct twl4030_prescale_divider_ratios twl4030_divider_ratios[16] = { {1, 1}, /* CHANNEL 0 No Prescaler */ {1, 1}, /* CHANNEL 1 No Prescaler */ {6, 10}, /* CHANNEL 2 */ {6, 10}, /* CHANNEL 3 */ {6, 10}, /* CHANNEL 4 */ {6, 10}, /* CHANNEL 5 */ {6, 10}, /* CHANNEL 6 */ {6, 10}, /* CHANNEL 7 */ {3, 14}, /* CHANNEL 8 */ {1, 3}, /* CHANNEL 9 */ {1, 1}, /* CHANNEL 10 No Prescaler */ {15, 100}, /* CHANNEL 11 */ {1, 4}, /* CHANNEL 12 */ {1, 1}, /* CHANNEL 13 Reserved channels */ {1, 1}, /* CHANNEL 14 Reseved channels */ {5, 11}, /* CHANNEL 15 */ }; /* * Conversion table from -3 to 55 degree Celcius */ static int therm_tbl[] = { 30800, 29500, 28300, 27100, 26000, 24900, 23900, 22900, 22000, 21100, 20300, 19400, 18700, 17900, 17200, 16500, 15900, 15300, 14700, 14100, 13600, 13100, 12600, 12100, 11600, 11200, 10800, 10400, 10000, 9630, 9280, 8950, 8620, 8310, 8020, 7730, 7460, 7200, 6950, 6710, 6470, 6250, 6040, 5830, 5640, 5450, 5260, 5090, 4920, 4760, 4600, 4450, 4310, 4170, 4040, 3910, 3790, 3670, 3550 }; /* * Structure containing the registers * of different conversion methods supported by MADC. * Hardware or RT real time conversion request initiated by external host * processor for RT Signal conversions. * External host processors can also request for non RT conversions * SW1 and SW2 software conversions also called asynchronous or GPC request. */ static const struct twl4030_madc_conversion_method twl4030_conversion_methods[] = { [TWL4030_MADC_RT] = { .sel = TWL4030_MADC_RTSELECT_LSB, .avg = TWL4030_MADC_RTAVERAGE_LSB, .rbase = TWL4030_MADC_RTCH0_LSB, }, [TWL4030_MADC_SW1] = { .sel = TWL4030_MADC_SW1SELECT_LSB, .avg = TWL4030_MADC_SW1AVERAGE_LSB, .rbase = TWL4030_MADC_GPCH0_LSB, .ctrl = TWL4030_MADC_CTRL_SW1, }, [TWL4030_MADC_SW2] = { .sel = TWL4030_MADC_SW2SELECT_LSB, .avg = TWL4030_MADC_SW2AVERAGE_LSB, .rbase = TWL4030_MADC_GPCH0_LSB, .ctrl = TWL4030_MADC_CTRL_SW2, }, }; /* * Function to read a particular channel value. * @madc - pointer to struct twl4030_madc_data * @reg - lsb of ADC Channel * If the i2c read fails it returns an error else returns 0. */ static int twl4030_madc_channel_raw_read(struct twl4030_madc_data *madc, u8 reg) { u8 msb, lsb; int ret; /* * For each ADC channel, we have MSB and LSB register pair. MSB address * is always LSB address+1. reg parameter is the address of LSB register */ ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &msb, reg + 1); if (ret) { dev_err(madc->dev, "unable to read MSB register 0x%X\n", reg + 1); return ret; } ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &lsb, reg); if (ret) { dev_err(madc->dev, "unable to read LSB register 0x%X\n", reg); return ret; } return (int)(((msb << 8) | lsb) >> 6); } /* * Return battery temperature * Or < 0 on failure. */ static int twl4030battery_temperature(int raw_volt) { u8 val; int temp, curr, volt, res, ret; volt = (raw_volt * TEMP_STEP_SIZE) / TEMP_PSR_R; /* Getting and calculating the supply current in micro ampers */ ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE, &val, REG_BCICTL2); if (ret < 0) return ret; curr = ((val & TWL4030_BCI_ITHEN) + 1) * 10; /* Getting and calculating the thermistor resistance in ohms */ res = volt * 1000 / curr; /* calculating temperature */ for (temp = 58; temp >= 0; temp--) { int actual = therm_tbl[temp]; if ((actual - res) >= 0) break; } return temp + 1; } static int twl4030battery_current(int raw_volt) { int ret; u8 val; ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE, &val, TWL4030_BCI_BCICTL1); if (ret) return ret; if (val & TWL4030_BCI_CGAIN) /* slope of 0.44 mV/mA */ return (raw_volt * CURR_STEP_SIZE) / CURR_PSR_R1; else /* slope of 0.88 mV/mA */ return (raw_volt * CURR_STEP_SIZE) / CURR_PSR_R2; } /* * Function to read channel values * @madc - pointer to twl4030_madc_data struct * @reg_base - Base address of the first channel * @Channels - 16 bit bitmap. If the bit is set, channel value is read * @buf - The channel values are stored here. if read fails error * value is stored * Returns the number of successfully read channels. */ static int twl4030_madc_read_channels(struct twl4030_madc_data *madc, u8 reg_base, unsigned long channels, int *buf) { int count = 0, count_req = 0, i; u8 reg; for_each_set_bit(i, &channels, TWL4030_MADC_MAX_CHANNELS) { reg = reg_base + 2 * i; buf[i] = twl4030_madc_channel_raw_read(madc, reg); if (buf[i] < 0) { dev_err(madc->dev, "Unable to read register 0x%X\n", reg); count_req++; continue; } switch (i) { case 10: buf[i] = twl4030battery_current(buf[i]); if (buf[i] < 0) { dev_err(madc->dev, "err reading current\n"); count_req++; } else { count++; buf[i] = buf[i] - 750; } break; case 1: buf[i] = twl4030battery_temperature(buf[i]); if (buf[i] < 0) { dev_err(madc->dev, "err reading temperature\n"); count_req++; } else { buf[i] -= 3; count++; } break; default: count++; /* Analog Input (V) = conv_result * step_size / R * conv_result = decimal value of 10-bit conversion * result * step size = 1.5 / (2 ^ 10 -1) * R = Prescaler ratio for input channels. * Result given in mV hence multiplied by 1000. */ buf[i] = (buf[i] * 3 * 1000 * twl4030_divider_ratios[i].denominator) / (2 * 1023 * twl4030_divider_ratios[i].numerator); } } if (count_req) dev_err(madc->dev, "%d channel conversion failed\n", count_req); return count; } /* * Enables irq. * @madc - pointer to twl4030_madc_data struct * @id - irq number to be enabled * can take one of TWL4030_MADC_RT, TWL4030_MADC_SW1, TWL4030_MADC_SW2 * corresponding to RT, SW1, SW2 conversion requests. * If the i2c read fails it returns an error else returns 0. */ static int twl4030_madc_enable_irq(struct twl4030_madc_data *madc, u8 id) { u8 val; int ret; ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &val, madc->imr); if (ret) { dev_err(madc->dev, "unable to read imr register 0x%X\n", madc->imr); return ret; } val &= ~(1 << id); ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, val, madc->imr); if (ret) { dev_err(madc->dev, "unable to write imr register 0x%X\n", madc->imr); return ret; } return 0; } /* * Disables irq. * @madc - pointer to twl4030_madc_data struct * @id - irq number to be disabled * can take one of TWL4030_MADC_RT, TWL4030_MADC_SW1, TWL4030_MADC_SW2 * corresponding to RT, SW1, SW2 conversion requests. * Returns error if i2c read/write fails. */ static int twl4030_madc_disable_irq(struct twl4030_madc_data *madc, u8 id) { u8 val; int ret; ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &val, madc->imr); if (ret) { dev_err(madc->dev, "unable to read imr register 0x%X\n", madc->imr); return ret; } val |= (1 << id); ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, val, madc->imr); if (ret) { dev_err(madc->dev, "unable to write imr register 0x%X\n", madc->imr); return ret; } return 0; } static irqreturn_t twl4030_madc_threaded_irq_handler(int irq, void *_madc) { struct twl4030_madc_data *madc = _madc; const struct twl4030_madc_conversion_method *method; u8 isr_val, imr_val; int i, len, ret; struct twl4030_madc_request *r; mutex_lock(&madc->lock); ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &isr_val, madc->isr); if (ret) { dev_err(madc->dev, "unable to read isr register 0x%X\n", madc->isr); goto err_i2c; } ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &imr_val, madc->imr); if (ret) { dev_err(madc->dev, "unable to read imr register 0x%X\n", madc->imr); goto err_i2c; } isr_val &= ~imr_val; for (i = 0; i < TWL4030_MADC_NUM_METHODS; i++) { if (!(isr_val & (1 << i))) continue; ret = twl4030_madc_disable_irq(madc, i); if (ret < 0) dev_dbg(madc->dev, "Disable interrupt failed%d\n", i); madc->requests[i].result_pending = 1; } for (i = 0; i < TWL4030_MADC_NUM_METHODS; i++) { r = &madc->requests[i]; /* No pending results for this method, move to next one */ if (!r->result_pending) continue; method = &twl4030_conversion_methods[r->method]; /* Read results */ len = twl4030_madc_read_channels(madc, method->rbase, r->channels, r->rbuf); /* Return results to caller */ if (r->func_cb != NULL) { r->func_cb(len, r->channels, r->rbuf); r->func_cb = NULL; } /* Free request */ r->result_pending = 0; r->active = 0; } mutex_unlock(&madc->lock); return IRQ_HANDLED; err_i2c: /* * In case of error check whichever request is active * and service the same. */ for (i = 0; i < TWL4030_MADC_NUM_METHODS; i++) { r = &madc->requests[i]; if (r->active == 0) continue; method = &twl4030_conversion_methods[r->method]; /* Read results */ len = twl4030_madc_read_channels(madc, method->rbase, r->channels, r->rbuf); /* Return results to caller */ if (r->func_cb != NULL) { r->func_cb(len, r->channels, r->rbuf); r->func_cb = NULL; } /* Free request */ r->result_pending = 0; r->active = 0; } mutex_unlock(&madc->lock); return IRQ_HANDLED; } static int twl4030_madc_set_irq(struct twl4030_madc_data *madc, struct twl4030_madc_request *req) { struct twl4030_madc_request *p; int ret; p = &madc->requests[req->method]; memcpy(p, req, sizeof(*req)); ret = twl4030_madc_enable_irq(madc, req->method); if (ret < 0) { dev_err(madc->dev, "enable irq failed!!\n"); return ret; } return 0; } /* * Function which enables the madc conversion * by writing to the control register. * @madc - pointer to twl4030_madc_data struct * @conv_method - can be TWL4030_MADC_RT, TWL4030_MADC_SW2, TWL4030_MADC_SW1 * corresponding to RT SW1 or SW2 conversion methods. * Returns 0 if succeeds else a negative error value */ static int twl4030_madc_start_conversion(struct twl4030_madc_data *madc, int conv_method) { const struct twl4030_madc_conversion_method *method; int ret = 0; method = &twl4030_conversion_methods[conv_method]; switch (conv_method) { case TWL4030_MADC_SW1: case TWL4030_MADC_SW2: ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, TWL4030_MADC_SW_START, method->ctrl); if (ret) { dev_err(madc->dev, "unable to write ctrl register 0x%X\n", method->ctrl); return ret; } break; default: break; } return 0; } /* * Function that waits for conversion to be ready * @madc - pointer to twl4030_madc_data struct * @timeout_ms - timeout value in milliseconds * @status_reg - ctrl register * returns 0 if succeeds else a negative error value */ static int twl4030_madc_wait_conversion_ready(struct twl4030_madc_data *madc, unsigned int timeout_ms, u8 status_reg) { unsigned long timeout; int ret; timeout = jiffies + msecs_to_jiffies(timeout_ms); do { u8 reg; ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, ®, status_reg); if (ret) { dev_err(madc->dev, "unable to read status register 0x%X\n", status_reg); return ret; } if (!(reg & TWL4030_MADC_BUSY) && (reg & TWL4030_MADC_EOC_SW)) return 0; usleep_range(500, 2000); } while (!time_after(jiffies, timeout)); dev_err(madc->dev, "conversion timeout!\n"); return -EAGAIN; } /* * An exported function which can be called from other kernel drivers. * @req twl4030_madc_request structure * req->rbuf will be filled with read values of channels based on the * channel index. If a particular channel reading fails there will * be a negative error value in the corresponding array element. * returns 0 if succeeds else error value */ int twl4030_madc_conversion(struct twl4030_madc_request *req) { const struct twl4030_madc_conversion_method *method; u8 ch_msb, ch_lsb; int ret; if (!req || !twl4030_madc) return -EINVAL; mutex_lock(&twl4030_madc->lock); if (req->method < TWL4030_MADC_RT || req->method > TWL4030_MADC_SW2) { ret = -EINVAL; goto out; } /* Do we have a conversion request ongoing */ if (twl4030_madc->requests[req->method].active) { ret = -EBUSY; goto out; } ch_msb = (req->channels >> 8) & 0xff; ch_lsb = req->channels & 0xff; method = &twl4030_conversion_methods[req->method]; /* Select channels to be converted */ ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, ch_msb, method->sel + 1); if (ret) { dev_err(twl4030_madc->dev, "unable to write sel register 0x%X\n", method->sel + 1); goto out; } ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, ch_lsb, method->sel); if (ret) { dev_err(twl4030_madc->dev, "unable to write sel register 0x%X\n", method->sel + 1); goto out; } /* Select averaging for all channels if do_avg is set */ if (req->do_avg) { ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, ch_msb, method->avg + 1); if (ret) { dev_err(twl4030_madc->dev, "unable to write avg register 0x%X\n", method->avg + 1); goto out; } ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, ch_lsb, method->avg); if (ret) { dev_err(twl4030_madc->dev, "unable to write sel reg 0x%X\n", method->sel + 1); goto out; } } if (req->type == TWL4030_MADC_IRQ_ONESHOT && req->func_cb != NULL) { ret = twl4030_madc_set_irq(twl4030_madc, req); if (ret < 0) goto out; ret = twl4030_madc_start_conversion(twl4030_madc, req->method); if (ret < 0) goto out; twl4030_madc->requests[req->method].active = 1; ret = 0; goto out; } /* With RT method we should not be here anymore */ if (req->method == TWL4030_MADC_RT) { ret = -EINVAL; goto out; } ret = twl4030_madc_start_conversion(twl4030_madc, req->method); if (ret < 0) goto out; twl4030_madc->requests[req->method].active = 1; /* Wait until conversion is ready (ctrl register returns EOC) */ ret = twl4030_madc_wait_conversion_ready(twl4030_madc, 5, method->ctrl); if (ret) { twl4030_madc->requests[req->method].active = 0; goto out; } ret = twl4030_madc_read_channels(twl4030_madc, method->rbase, req->channels, req->rbuf); twl4030_madc->requests[req->method].active = 0; out: mutex_unlock(&twl4030_madc->lock); return ret; } EXPORT_SYMBOL_GPL(twl4030_madc_conversion); /* * Return channel value * Or < 0 on failure. */ int twl4030_get_madc_conversion(int channel_no) { struct twl4030_madc_request req; int temp = 0; int ret; req.channels = (1 << channel_no); req.method = TWL4030_MADC_SW2; req.active = 0; req.func_cb = NULL; ret = twl4030_madc_conversion(&req); if (ret < 0) return ret; if (req.rbuf[channel_no] > 0) temp = req.rbuf[channel_no]; return temp; } EXPORT_SYMBOL_GPL(twl4030_get_madc_conversion); /* * Function to enable or disable bias current for * main battery type reading or temperature sensing * @madc - pointer to twl4030_madc_data struct * @chan - can be one of the two values * TWL4030_BCI_ITHEN - Enables bias current for main battery type reading * TWL4030_BCI_TYPEN - Enables bias current for main battery temperature * sensing * @on - enable or disable chan. */ static int twl4030_madc_set_current_generator(struct twl4030_madc_data *madc, int chan, int on) { int ret; u8 regval; ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE, ®val, TWL4030_BCI_BCICTL1); if (ret) { dev_err(madc->dev, "unable to read BCICTL1 reg 0x%X", TWL4030_BCI_BCICTL1); return ret; } if (on) regval |= chan ? TWL4030_BCI_ITHEN : TWL4030_BCI_TYPEN; else regval &= chan ? ~TWL4030_BCI_ITHEN : ~TWL4030_BCI_TYPEN; ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, regval, TWL4030_BCI_BCICTL1); if (ret) { dev_err(madc->dev, "unable to write BCICTL1 reg 0x%X\n", TWL4030_BCI_BCICTL1); return ret; } return 0; } /* * Function that sets MADC software power on bit to enable MADC * @madc - pointer to twl4030_madc_data struct * @on - Enable or disable MADC software powen on bit. * returns error if i2c read/write fails else 0 */ static int twl4030_madc_set_power(struct twl4030_madc_data *madc, int on) { u8 regval; int ret; ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE, ®val, TWL4030_MADC_CTRL1); if (ret) { dev_err(madc->dev, "unable to read madc ctrl1 reg 0x%X\n", TWL4030_MADC_CTRL1); return ret; } if (on) regval |= TWL4030_MADC_MADCON; else regval &= ~TWL4030_MADC_MADCON; ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, regval, TWL4030_MADC_CTRL1); if (ret) { dev_err(madc->dev, "unable to write madc ctrl1 reg 0x%X\n", TWL4030_MADC_CTRL1); return ret; } return 0; } /* * Initialize MADC and request for threaded irq */ static int __devinit twl4030_madc_probe(struct platform_device *pdev) { struct twl4030_madc_data *madc; struct twl4030_madc_platform_data *pdata = pdev->dev.platform_data; int ret; u8 regval; if (!pdata) { dev_err(&pdev->dev, "platform_data not available\n"); return -EINVAL; } madc = kzalloc(sizeof(*madc), GFP_KERNEL); if (!madc) return -ENOMEM; madc->dev = &pdev->dev; /* * Phoenix provides 2 interrupt lines. The first one is connected to * the OMAP. The other one can be connected to the other processor such * as modem. Hence two separate ISR and IMR registers. */ madc->imr = (pdata->irq_line == 1) ? TWL4030_MADC_IMR1 : TWL4030_MADC_IMR2; madc->isr = (pdata->irq_line == 1) ? TWL4030_MADC_ISR1 : TWL4030_MADC_ISR2; ret = twl4030_madc_set_power(madc, 1); if (ret < 0) goto err_power; ret = twl4030_madc_set_current_generator(madc, 0, 1); if (ret < 0) goto err_current_generator; ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE, ®val, TWL4030_BCI_BCICTL1); if (ret) { dev_err(&pdev->dev, "unable to read reg BCI CTL1 0x%X\n", TWL4030_BCI_BCICTL1); goto err_i2c; } regval |= TWL4030_BCI_MESBAT; ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, regval, TWL4030_BCI_BCICTL1); if (ret) { dev_err(&pdev->dev, "unable to write reg BCI Ctl1 0x%X\n", TWL4030_BCI_BCICTL1); goto err_i2c; } /* Check that MADC clock is on */ ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, ®val, TWL4030_REG_GPBR1); if (ret) { dev_err(&pdev->dev, "unable to read reg GPBR1 0x%X\n", TWL4030_REG_GPBR1); goto err_i2c; } /* If MADC clk is not on, turn it on */ if (!(regval & TWL4030_GPBR1_MADC_HFCLK_EN)) { dev_info(&pdev->dev, "clk disabled, enabling\n"); regval |= TWL4030_GPBR1_MADC_HFCLK_EN; ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, regval, TWL4030_REG_GPBR1); if (ret) { dev_err(&pdev->dev, "unable to write reg GPBR1 0x%X\n", TWL4030_REG_GPBR1); goto err_i2c; } } platform_set_drvdata(pdev, madc); mutex_init(&madc->lock); ret = request_threaded_irq(platform_get_irq(pdev, 0), NULL, twl4030_madc_threaded_irq_handler, IRQF_TRIGGER_RISING, "twl4030_madc", madc); if (ret) { dev_dbg(&pdev->dev, "could not request irq\n"); goto err_irq; } twl4030_madc = madc; return 0; err_irq: platform_set_drvdata(pdev, NULL); err_i2c: twl4030_madc_set_current_generator(madc, 0, 0); err_current_generator: twl4030_madc_set_power(madc, 0); err_power: kfree(madc); return ret; } static int __devexit twl4030_madc_remove(struct platform_device *pdev) { struct twl4030_madc_data *madc = platform_get_drvdata(pdev); free_irq(platform_get_irq(pdev, 0), madc); platform_set_drvdata(pdev, NULL); twl4030_madc_set_current_generator(madc, 0, 0); twl4030_madc_set_power(madc, 0); kfree(madc); return 0; } static struct platform_driver twl4030_madc_driver = { .probe = twl4030_madc_probe, .remove = __exit_p(twl4030_madc_remove), .driver = { .name = "twl4030_madc", .owner = THIS_MODULE, }, }; module_platform_driver(twl4030_madc_driver); MODULE_DESCRIPTION("TWL4030 ADC driver"); MODULE_LICENSE("GPL"); MODULE_AUTHOR("J Keerthy"); MODULE_ALIAS("platform:twl4030_madc");