/* * TI ADC MFD driver * * Copyright (C) 2012 Texas Instruments Incorporated - https://www.ti.com/ * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation version 2. * * This program is distributed "as is" WITHOUT ANY WARRANTY of any * kind, whether express or implied; without even the implied warranty * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define DMA_BUFFER_SIZE SZ_2K struct tiadc_dma { struct dma_slave_config conf; struct dma_chan *chan; dma_addr_t addr; dma_cookie_t cookie; u8 *buf; int current_period; int period_size; u8 fifo_thresh; }; struct tiadc_device { struct ti_tscadc_dev *mfd_tscadc; struct tiadc_dma dma; struct mutex fifo1_lock; /* to protect fifo access */ int channels; int total_ch_enabled; u8 channel_line[8]; u8 channel_step[8]; int buffer_en_ch_steps; u16 data[8]; u32 open_delay[8], sample_delay[8], step_avg[8]; }; static unsigned int tiadc_readl(struct tiadc_device *adc, unsigned int reg) { return readl(adc->mfd_tscadc->tscadc_base + reg); } static void tiadc_writel(struct tiadc_device *adc, unsigned int reg, unsigned int val) { writel(val, adc->mfd_tscadc->tscadc_base + reg); } static u32 get_adc_step_mask(struct tiadc_device *adc_dev) { u32 step_en; step_en = ((1 << adc_dev->channels) - 1); step_en <<= TOTAL_STEPS - adc_dev->channels + 1; return step_en; } static u32 get_adc_chan_step_mask(struct tiadc_device *adc_dev, struct iio_chan_spec const *chan) { int i; for (i = 0; i < ARRAY_SIZE(adc_dev->channel_step); i++) { if (chan->channel == adc_dev->channel_line[i]) { u32 step; step = adc_dev->channel_step[i]; /* +1 for the charger */ return 1 << (step + 1); } } WARN_ON(1); return 0; } static u32 get_adc_step_bit(struct tiadc_device *adc_dev, int chan) { return 1 << adc_dev->channel_step[chan]; } static void tiadc_step_config(struct iio_dev *indio_dev) { struct tiadc_device *adc_dev = iio_priv(indio_dev); struct device *dev = adc_dev->mfd_tscadc->dev; unsigned int stepconfig; int i, steps = 0; /* * There are 16 configurable steps and 8 analog input * lines available which are shared between Touchscreen and ADC. * * Steps forwards i.e. from 0 towards 16 are used by ADC * depending on number of input lines needed. * Channel would represent which analog input * needs to be given to ADC to digitalize data. */ for (i = 0; i < adc_dev->channels; i++) { int chan; chan = adc_dev->channel_line[i]; if (adc_dev->step_avg[i] > STEPCONFIG_AVG_16) { dev_warn(dev, "chan %d step_avg truncating to %d\n", chan, STEPCONFIG_AVG_16); adc_dev->step_avg[i] = STEPCONFIG_AVG_16; } if (adc_dev->step_avg[i]) stepconfig = STEPCONFIG_AVG(ffs(adc_dev->step_avg[i]) - 1) | STEPCONFIG_FIFO1; else stepconfig = STEPCONFIG_FIFO1; if (iio_buffer_enabled(indio_dev)) stepconfig |= STEPCONFIG_MODE_SWCNT; tiadc_writel(adc_dev, REG_STEPCONFIG(steps), stepconfig | STEPCONFIG_INP(chan) | STEPCONFIG_INM_ADCREFM | STEPCONFIG_RFP_VREFP | STEPCONFIG_RFM_VREFN); if (adc_dev->open_delay[i] > STEPDELAY_OPEN_MASK) { dev_warn(dev, "chan %d open delay truncating to 0x3FFFF\n", chan); adc_dev->open_delay[i] = STEPDELAY_OPEN_MASK; } if (adc_dev->sample_delay[i] > 0xFF) { dev_warn(dev, "chan %d sample delay truncating to 0xFF\n", chan); adc_dev->sample_delay[i] = 0xFF; } tiadc_writel(adc_dev, REG_STEPDELAY(steps), STEPDELAY_OPEN(adc_dev->open_delay[i]) | STEPDELAY_SAMPLE(adc_dev->sample_delay[i])); adc_dev->channel_step[i] = steps; steps++; } } static irqreturn_t tiadc_irq_h(int irq, void *private) { struct iio_dev *indio_dev = private; struct tiadc_device *adc_dev = iio_priv(indio_dev); unsigned int status, config, adc_fsm; unsigned short count = 0; status = tiadc_readl(adc_dev, REG_IRQSTATUS); /* * ADC and touchscreen share the IRQ line. * FIFO0 interrupts are used by TSC. Handle FIFO1 IRQs here only */ if (status & IRQENB_FIFO1OVRRUN) { /* FIFO Overrun. Clear flag. Disable/Enable ADC to recover */ config = tiadc_readl(adc_dev, REG_CTRL); config &= ~(CNTRLREG_TSCSSENB); tiadc_writel(adc_dev, REG_CTRL, config); tiadc_writel(adc_dev, REG_IRQSTATUS, IRQENB_FIFO1OVRRUN | IRQENB_FIFO1UNDRFLW | IRQENB_FIFO1THRES); /* wait for idle state. * ADC needs to finish the current conversion * before disabling the module */ do { adc_fsm = tiadc_readl(adc_dev, REG_ADCFSM); } while (adc_fsm != 0x10 && count++ < 100); tiadc_writel(adc_dev, REG_CTRL, (config | CNTRLREG_TSCSSENB)); return IRQ_HANDLED; } else if (status & IRQENB_FIFO1THRES) { /* Disable irq and wake worker thread */ tiadc_writel(adc_dev, REG_IRQCLR, IRQENB_FIFO1THRES); return IRQ_WAKE_THREAD; } return IRQ_NONE; } static irqreturn_t tiadc_worker_h(int irq, void *private) { struct iio_dev *indio_dev = private; struct tiadc_device *adc_dev = iio_priv(indio_dev); int i, k, fifo1count, read; u16 *data = adc_dev->data; fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT); for (k = 0; k < fifo1count; k = k + i) { for (i = 0; i < (indio_dev->scan_bytes)/2; i++) { read = tiadc_readl(adc_dev, REG_FIFO1); data[i] = read & FIFOREAD_DATA_MASK; } iio_push_to_buffers(indio_dev, (u8 *) data); } tiadc_writel(adc_dev, REG_IRQSTATUS, IRQENB_FIFO1THRES); tiadc_writel(adc_dev, REG_IRQENABLE, IRQENB_FIFO1THRES); return IRQ_HANDLED; } static void tiadc_dma_rx_complete(void *param) { struct iio_dev *indio_dev = param; struct tiadc_device *adc_dev = iio_priv(indio_dev); struct tiadc_dma *dma = &adc_dev->dma; u8 *data; int i; data = dma->buf + dma->current_period * dma->period_size; dma->current_period = 1 - dma->current_period; /* swap the buffer ID */ for (i = 0; i < dma->period_size; i += indio_dev->scan_bytes) { iio_push_to_buffers(indio_dev, data); data += indio_dev->scan_bytes; } } static int tiadc_start_dma(struct iio_dev *indio_dev) { struct tiadc_device *adc_dev = iio_priv(indio_dev); struct tiadc_dma *dma = &adc_dev->dma; struct dma_async_tx_descriptor *desc; dma->current_period = 0; /* We start to fill period 0 */ /* * Make the fifo thresh as the multiple of total number of * channels enabled, so make sure that cyclic DMA period * length is also a multiple of total number of channels * enabled. This ensures that no invalid data is reported * to the stack via iio_push_to_buffers(). */ dma->fifo_thresh = rounddown(FIFO1_THRESHOLD + 1, adc_dev->total_ch_enabled) - 1; /* Make sure that period length is multiple of fifo thresh level */ dma->period_size = rounddown(DMA_BUFFER_SIZE / 2, (dma->fifo_thresh + 1) * sizeof(u16)); dma->conf.src_maxburst = dma->fifo_thresh + 1; dmaengine_slave_config(dma->chan, &dma->conf); desc = dmaengine_prep_dma_cyclic(dma->chan, dma->addr, dma->period_size * 2, dma->period_size, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT); if (!desc) return -EBUSY; desc->callback = tiadc_dma_rx_complete; desc->callback_param = indio_dev; dma->cookie = dmaengine_submit(desc); dma_async_issue_pending(dma->chan); tiadc_writel(adc_dev, REG_FIFO1THR, dma->fifo_thresh); tiadc_writel(adc_dev, REG_DMA1REQ, dma->fifo_thresh); tiadc_writel(adc_dev, REG_DMAENABLE_SET, DMA_FIFO1); return 0; } static int tiadc_buffer_preenable(struct iio_dev *indio_dev) { struct tiadc_device *adc_dev = iio_priv(indio_dev); int i, fifo1count, read; tiadc_writel(adc_dev, REG_IRQCLR, (IRQENB_FIFO1THRES | IRQENB_FIFO1OVRRUN | IRQENB_FIFO1UNDRFLW)); /* Flush FIFO. Needed in corner cases in simultaneous tsc/adc use */ fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT); for (i = 0; i < fifo1count; i++) read = tiadc_readl(adc_dev, REG_FIFO1); return 0; } static int tiadc_buffer_postenable(struct iio_dev *indio_dev) { struct tiadc_device *adc_dev = iio_priv(indio_dev); struct tiadc_dma *dma = &adc_dev->dma; unsigned int irq_enable; unsigned int enb = 0; u8 bit; tiadc_step_config(indio_dev); for_each_set_bit(bit, indio_dev->active_scan_mask, adc_dev->channels) { enb |= (get_adc_step_bit(adc_dev, bit) << 1); adc_dev->total_ch_enabled++; } adc_dev->buffer_en_ch_steps = enb; if (dma->chan) tiadc_start_dma(indio_dev); am335x_tsc_se_set_cache(adc_dev->mfd_tscadc, enb); tiadc_writel(adc_dev, REG_IRQSTATUS, IRQENB_FIFO1THRES | IRQENB_FIFO1OVRRUN | IRQENB_FIFO1UNDRFLW); irq_enable = IRQENB_FIFO1OVRRUN; if (!dma->chan) irq_enable |= IRQENB_FIFO1THRES; tiadc_writel(adc_dev, REG_IRQENABLE, irq_enable); return 0; } static int tiadc_buffer_predisable(struct iio_dev *indio_dev) { struct tiadc_device *adc_dev = iio_priv(indio_dev); struct tiadc_dma *dma = &adc_dev->dma; int fifo1count, i, read; tiadc_writel(adc_dev, REG_IRQCLR, (IRQENB_FIFO1THRES | IRQENB_FIFO1OVRRUN | IRQENB_FIFO1UNDRFLW)); am335x_tsc_se_clr(adc_dev->mfd_tscadc, adc_dev->buffer_en_ch_steps); adc_dev->buffer_en_ch_steps = 0; adc_dev->total_ch_enabled = 0; if (dma->chan) { tiadc_writel(adc_dev, REG_DMAENABLE_CLEAR, 0x2); dmaengine_terminate_async(dma->chan); } /* Flush FIFO of leftover data in the time it takes to disable adc */ fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT); for (i = 0; i < fifo1count; i++) read = tiadc_readl(adc_dev, REG_FIFO1); return 0; } static int tiadc_buffer_postdisable(struct iio_dev *indio_dev) { tiadc_step_config(indio_dev); return 0; } static const struct iio_buffer_setup_ops tiadc_buffer_setup_ops = { .preenable = &tiadc_buffer_preenable, .postenable = &tiadc_buffer_postenable, .predisable = &tiadc_buffer_predisable, .postdisable = &tiadc_buffer_postdisable, }; static int tiadc_iio_buffered_hardware_setup(struct device *dev, struct iio_dev *indio_dev, irqreturn_t (*pollfunc_bh)(int irq, void *p), irqreturn_t (*pollfunc_th)(int irq, void *p), int irq, unsigned long flags, const struct iio_buffer_setup_ops *setup_ops) { struct iio_buffer *buffer; int ret; buffer = devm_iio_kfifo_allocate(dev); if (!buffer) return -ENOMEM; iio_device_attach_buffer(indio_dev, buffer); ret = devm_request_threaded_irq(dev, irq, pollfunc_th, pollfunc_bh, flags, indio_dev->name, indio_dev); if (ret) goto error_kfifo_free; indio_dev->setup_ops = setup_ops; indio_dev->modes |= INDIO_BUFFER_SOFTWARE; return 0; error_kfifo_free: iio_kfifo_free(indio_dev->buffer); return ret; } static const char * const chan_name_ain[] = { "AIN0", "AIN1", "AIN2", "AIN3", "AIN4", "AIN5", "AIN6", "AIN7", }; static int tiadc_channel_init(struct device *dev, struct iio_dev *indio_dev, int channels) { struct tiadc_device *adc_dev = iio_priv(indio_dev); struct iio_chan_spec *chan_array; struct iio_chan_spec *chan; int i; indio_dev->num_channels = channels; chan_array = devm_kcalloc(dev, channels, sizeof(*chan_array), GFP_KERNEL); if (chan_array == NULL) return -ENOMEM; chan = chan_array; for (i = 0; i < channels; i++, chan++) { chan->type = IIO_VOLTAGE; chan->indexed = 1; chan->channel = adc_dev->channel_line[i]; chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW); chan->datasheet_name = chan_name_ain[chan->channel]; chan->scan_index = i; chan->scan_type.sign = 'u'; chan->scan_type.realbits = 12; chan->scan_type.storagebits = 16; } indio_dev->channels = chan_array; return 0; } static int tiadc_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct tiadc_device *adc_dev = iio_priv(indio_dev); int ret = IIO_VAL_INT; int i, map_val; unsigned int fifo1count, read, stepid; bool found = false; u32 step_en; unsigned long timeout; if (iio_buffer_enabled(indio_dev)) return -EBUSY; step_en = get_adc_chan_step_mask(adc_dev, chan); if (!step_en) return -EINVAL; mutex_lock(&adc_dev->fifo1_lock); fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT); while (fifo1count--) tiadc_readl(adc_dev, REG_FIFO1); am335x_tsc_se_set_once(adc_dev->mfd_tscadc, step_en); timeout = jiffies + msecs_to_jiffies (IDLE_TIMEOUT * adc_dev->channels); /* Wait for Fifo threshold interrupt */ while (1) { fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT); if (fifo1count) break; if (time_after(jiffies, timeout)) { am335x_tsc_se_adc_done(adc_dev->mfd_tscadc); ret = -EAGAIN; goto err_unlock; } } map_val = adc_dev->channel_step[chan->scan_index]; /* * We check the complete FIFO. We programmed just one entry but in case * something went wrong we left empty handed (-EAGAIN previously) and * then the value apeared somehow in the FIFO we would have two entries. * Therefore we read every item and keep only the latest version of the * requested channel. */ for (i = 0; i < fifo1count; i++) { read = tiadc_readl(adc_dev, REG_FIFO1); stepid = read & FIFOREAD_CHNLID_MASK; stepid = stepid >> 0x10; if (stepid == map_val) { read = read & FIFOREAD_DATA_MASK; found = true; *val = (u16) read; } } am335x_tsc_se_adc_done(adc_dev->mfd_tscadc); if (!found) ret = -EBUSY; err_unlock: mutex_unlock(&adc_dev->fifo1_lock); return ret; } static const struct iio_info tiadc_info = { .read_raw = &tiadc_read_raw, }; static int tiadc_request_dma(struct platform_device *pdev, struct tiadc_device *adc_dev) { struct tiadc_dma *dma = &adc_dev->dma; dma_cap_mask_t mask; /* Default slave configuration parameters */ dma->conf.direction = DMA_DEV_TO_MEM; dma->conf.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES; dma->conf.src_addr = adc_dev->mfd_tscadc->tscadc_phys_base + REG_FIFO1; dma_cap_zero(mask); dma_cap_set(DMA_CYCLIC, mask); /* Get a channel for RX */ dma->chan = dma_request_chan(adc_dev->mfd_tscadc->dev, "fifo1"); if (IS_ERR(dma->chan)) { int ret = PTR_ERR(dma->chan); dma->chan = NULL; return ret; } /* RX buffer */ dma->buf = dma_alloc_coherent(dma->chan->device->dev, DMA_BUFFER_SIZE, &dma->addr, GFP_KERNEL); if (!dma->buf) goto err; return 0; err: dma_release_channel(dma->chan); return -ENOMEM; } static int tiadc_parse_dt(struct platform_device *pdev, struct tiadc_device *adc_dev) { struct device_node *node = pdev->dev.of_node; struct property *prop; const __be32 *cur; int channels = 0; u32 val; of_property_for_each_u32(node, "ti,adc-channels", prop, cur, val) { adc_dev->channel_line[channels] = val; /* Set Default values for optional DT parameters */ adc_dev->open_delay[channels] = STEPCONFIG_OPENDLY; adc_dev->sample_delay[channels] = STEPCONFIG_SAMPLEDLY; adc_dev->step_avg[channels] = 16; channels++; } of_property_read_u32_array(node, "ti,chan-step-avg", adc_dev->step_avg, channels); of_property_read_u32_array(node, "ti,chan-step-opendelay", adc_dev->open_delay, channels); of_property_read_u32_array(node, "ti,chan-step-sampledelay", adc_dev->sample_delay, channels); adc_dev->channels = channels; return 0; } static int tiadc_probe(struct platform_device *pdev) { struct iio_dev *indio_dev; struct tiadc_device *adc_dev; struct device_node *node = pdev->dev.of_node; int err; if (!node) { dev_err(&pdev->dev, "Could not find valid DT data.\n"); return -EINVAL; } indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc_dev)); if (indio_dev == NULL) { dev_err(&pdev->dev, "failed to allocate iio device\n"); return -ENOMEM; } adc_dev = iio_priv(indio_dev); adc_dev->mfd_tscadc = ti_tscadc_dev_get(pdev); tiadc_parse_dt(pdev, adc_dev); indio_dev->name = dev_name(&pdev->dev); indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->info = &tiadc_info; tiadc_step_config(indio_dev); tiadc_writel(adc_dev, REG_FIFO1THR, FIFO1_THRESHOLD); mutex_init(&adc_dev->fifo1_lock); err = tiadc_channel_init(&pdev->dev, indio_dev, adc_dev->channels); if (err < 0) return err; err = tiadc_iio_buffered_hardware_setup(&pdev->dev, indio_dev, &tiadc_worker_h, &tiadc_irq_h, adc_dev->mfd_tscadc->irq, IRQF_SHARED, &tiadc_buffer_setup_ops); if (err) goto err_free_channels; err = iio_device_register(indio_dev); if (err) goto err_buffer_unregister; platform_set_drvdata(pdev, indio_dev); err = tiadc_request_dma(pdev, adc_dev); if (err && err == -EPROBE_DEFER) goto err_dma; return 0; err_dma: iio_device_unregister(indio_dev); err_buffer_unregister: err_free_channels: return err; } static int tiadc_remove(struct platform_device *pdev) { struct iio_dev *indio_dev = platform_get_drvdata(pdev); struct tiadc_device *adc_dev = iio_priv(indio_dev); struct tiadc_dma *dma = &adc_dev->dma; u32 step_en; if (dma->chan) { dma_free_coherent(dma->chan->device->dev, DMA_BUFFER_SIZE, dma->buf, dma->addr); dma_release_channel(dma->chan); } iio_device_unregister(indio_dev); step_en = get_adc_step_mask(adc_dev); am335x_tsc_se_clr(adc_dev->mfd_tscadc, step_en); return 0; } static int __maybe_unused tiadc_suspend(struct device *dev) { struct iio_dev *indio_dev = dev_get_drvdata(dev); struct tiadc_device *adc_dev = iio_priv(indio_dev); unsigned int idle; idle = tiadc_readl(adc_dev, REG_CTRL); idle &= ~(CNTRLREG_TSCSSENB); tiadc_writel(adc_dev, REG_CTRL, (idle | CNTRLREG_POWERDOWN)); return 0; } static int __maybe_unused tiadc_resume(struct device *dev) { struct iio_dev *indio_dev = dev_get_drvdata(dev); struct tiadc_device *adc_dev = iio_priv(indio_dev); unsigned int restore; /* Make sure ADC is powered up */ restore = tiadc_readl(adc_dev, REG_CTRL); restore &= ~(CNTRLREG_POWERDOWN); tiadc_writel(adc_dev, REG_CTRL, restore); tiadc_step_config(indio_dev); am335x_tsc_se_set_cache(adc_dev->mfd_tscadc, adc_dev->buffer_en_ch_steps); return 0; } static SIMPLE_DEV_PM_OPS(tiadc_pm_ops, tiadc_suspend, tiadc_resume); static const struct of_device_id ti_adc_dt_ids[] = { { .compatible = "ti,am3359-adc", }, { } }; MODULE_DEVICE_TABLE(of, ti_adc_dt_ids); static struct platform_driver tiadc_driver = { .driver = { .name = "TI-am335x-adc", .pm = &tiadc_pm_ops, .of_match_table = ti_adc_dt_ids, }, .probe = tiadc_probe, .remove = tiadc_remove, }; module_platform_driver(tiadc_driver); MODULE_DESCRIPTION("TI ADC controller driver"); MODULE_AUTHOR("Rachna Patil "); MODULE_LICENSE("GPL");