--- /dev/null
+/*
+ * Driver for the ADC present in the Atmel AT91 evaluation boards.
+ *
+ * Copyright 2011 Free Electrons
+ *
+ * Licensed under the GPLv2 or later.
+ */
+
+#include <linux/bitmap.h>
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/wait.h>
+
+#include <linux/platform_data/at91_adc.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+/* Registers */
+#define AT91_ADC_CR 0x00 /* Control Register */
+#define AT91_ADC_SWRST (1 << 0) /* Software Reset */
+#define AT91_ADC_START (1 << 1) /* Start Conversion */
+
+#define AT91_ADC_MR 0x04 /* Mode Register */
+#define AT91_ADC_TSAMOD (3 << 0) /* ADC mode */
+#define AT91_ADC_TSAMOD_ADC_ONLY_MODE (0 << 0) /* ADC Mode */
+#define AT91_ADC_TSAMOD_TS_ONLY_MODE (1 << 0) /* Touch Screen Only Mode */
+#define AT91_ADC_TRGEN (1 << 0) /* Trigger Enable */
+#define AT91_ADC_TRGSEL (7 << 1) /* Trigger Selection */
+#define AT91_ADC_TRGSEL_TC0 (0 << 1)
+#define AT91_ADC_TRGSEL_TC1 (1 << 1)
+#define AT91_ADC_TRGSEL_TC2 (2 << 1)
+#define AT91_ADC_TRGSEL_EXTERNAL (6 << 1)
+#define AT91_ADC_LOWRES (1 << 4) /* Low Resolution */
+#define AT91_ADC_SLEEP (1 << 5) /* Sleep Mode */
+#define AT91_ADC_PENDET (1 << 6) /* Pen contact detection enable */
+#define AT91_ADC_PRESCAL_9260 (0x3f << 8) /* Prescalar Rate Selection */
+#define AT91_ADC_PRESCAL_9G45 (0xff << 8)
+#define AT91_ADC_PRESCAL_(x) ((x) << 8)
+#define AT91_ADC_STARTUP_9260 (0x1f << 16) /* Startup Up Time */
+#define AT91_ADC_STARTUP_9G45 (0x7f << 16)
+#define AT91_ADC_STARTUP_9X5 (0xf << 16)
+#define AT91_ADC_STARTUP_(x) ((x) << 16)
+#define AT91_ADC_SHTIM (0xf << 24) /* Sample & Hold Time */
+#define AT91_ADC_SHTIM_(x) ((x) << 24)
+#define AT91_ADC_PENDBC (0x0f << 28) /* Pen Debounce time */
+#define AT91_ADC_PENDBC_(x) ((x) << 28)
+
+#define AT91_ADC_TSR 0x0C
+#define AT91_ADC_TSR_SHTIM (0xf << 24) /* Sample & Hold Time */
+#define AT91_ADC_TSR_SHTIM_(x) ((x) << 24)
+
+#define AT91_ADC_CHER 0x10 /* Channel Enable Register */
+#define AT91_ADC_CHDR 0x14 /* Channel Disable Register */
+#define AT91_ADC_CHSR 0x18 /* Channel Status Register */
+#define AT91_ADC_CH(n) (1 << (n)) /* Channel Number */
+
+#define AT91_ADC_SR 0x1C /* Status Register */
+#define AT91_ADC_EOC(n) (1 << (n)) /* End of Conversion on Channel N */
+#define AT91_ADC_OVRE(n) (1 << ((n) + 8))/* Overrun Error on Channel N */
+#define AT91_ADC_DRDY (1 << 16) /* Data Ready */
+#define AT91_ADC_GOVRE (1 << 17) /* General Overrun Error */
+#define AT91_ADC_ENDRX (1 << 18) /* End of RX Buffer */
+#define AT91_ADC_RXFUFF (1 << 19) /* RX Buffer Full */
+
+#define AT91_ADC_SR_9X5 0x30 /* Status Register for 9x5 */
+#define AT91_ADC_SR_DRDY_9X5 (1 << 24) /* Data Ready */
+
+#define AT91_ADC_LCDR 0x20 /* Last Converted Data Register */
+#define AT91_ADC_LDATA (0x3ff)
+
+#define AT91_ADC_IER 0x24 /* Interrupt Enable Register */
+#define AT91_ADC_IDR 0x28 /* Interrupt Disable Register */
+#define AT91_ADC_IMR 0x2C /* Interrupt Mask Register */
+#define AT91RL_ADC_IER_PEN (1 << 20)
+#define AT91RL_ADC_IER_NOPEN (1 << 21)
+#define AT91_ADC_IER_PEN (1 << 29)
+#define AT91_ADC_IER_NOPEN (1 << 30)
+#define AT91_ADC_IER_XRDY (1 << 20)
+#define AT91_ADC_IER_YRDY (1 << 21)
+#define AT91_ADC_IER_PRDY (1 << 22)
+#define AT91_ADC_ISR_PENS (1 << 31)
+
+#define AT91_ADC_CHR(n) (0x30 + ((n) * 4)) /* Channel Data Register N */
+#define AT91_ADC_DATA (0x3ff)
+
+#define AT91_ADC_CDR0_9X5 (0x50) /* Channel Data Register 0 for 9X5 */
+
+#define AT91_ADC_ACR 0x94 /* Analog Control Register */
+#define AT91_ADC_ACR_PENDETSENS (0x3 << 0) /* pull-up resistor */
+
+#define AT91_ADC_TSMR 0xB0
+#define AT91_ADC_TSMR_TSMODE (3 << 0) /* Touch Screen Mode */
+#define AT91_ADC_TSMR_TSMODE_NONE (0 << 0)
+#define AT91_ADC_TSMR_TSMODE_4WIRE_NO_PRESS (1 << 0)
+#define AT91_ADC_TSMR_TSMODE_4WIRE_PRESS (2 << 0)
+#define AT91_ADC_TSMR_TSMODE_5WIRE (3 << 0)
+#define AT91_ADC_TSMR_TSAV (3 << 4) /* Averages samples */
+#define AT91_ADC_TSMR_TSAV_(x) ((x) << 4)
+#define AT91_ADC_TSMR_SCTIM (0x0f << 16) /* Switch closure time */
+#define AT91_ADC_TSMR_PENDBC (0x0f << 28) /* Pen Debounce time */
+#define AT91_ADC_TSMR_PENDBC_(x) ((x) << 28)
+#define AT91_ADC_TSMR_NOTSDMA (1 << 22) /* No Touchscreen DMA */
+#define AT91_ADC_TSMR_PENDET_DIS (0 << 24) /* Pen contact detection disable */
+#define AT91_ADC_TSMR_PENDET_ENA (1 << 24) /* Pen contact detection enable */
+
+#define AT91_ADC_TSXPOSR 0xB4
+#define AT91_ADC_TSYPOSR 0xB8
+#define AT91_ADC_TSPRESSR 0xBC
+
+#define AT91_ADC_TRGR_9260 AT91_ADC_MR
+#define AT91_ADC_TRGR_9G45 0x08
+#define AT91_ADC_TRGR_9X5 0xC0
+
+/* Trigger Register bit field */
+#define AT91_ADC_TRGR_TRGPER (0xffff << 16)
+#define AT91_ADC_TRGR_TRGPER_(x) ((x) << 16)
+#define AT91_ADC_TRGR_TRGMOD (0x7 << 0)
+#define AT91_ADC_TRGR_NONE (0 << 0)
+#define AT91_ADC_TRGR_MOD_PERIOD_TRIG (5 << 0)
+
+#define AT91_ADC_CHAN(st, ch) \
+ (st->registers->channel_base + (ch * 4))
+#define at91_adc_readl(st, reg) \
+ (readl_relaxed(st->reg_base + reg))
+#define at91_adc_writel(st, reg, val) \
+ (writel_relaxed(val, st->reg_base + reg))
+
+#define DRIVER_NAME "at91_adc"
+#define MAX_POS_BITS 12
+
+#define TOUCH_SAMPLE_PERIOD_US 2000 /* 2ms */
+#define TOUCH_PEN_DETECT_DEBOUNCE_US 200
+
+#define MAX_RLPOS_BITS 10
+#define TOUCH_SAMPLE_PERIOD_US_RL 10000 /* 10ms, the SoC can't keep up with 2ms */
+#define TOUCH_SHTIM 0xa
+
+/**
+ * struct at91_adc_reg_desc - Various informations relative to registers
+ * @channel_base: Base offset for the channel data registers
+ * @drdy_mask: Mask of the DRDY field in the relevant registers
+ (Interruptions registers mostly)
+ * @status_register: Offset of the Interrupt Status Register
+ * @trigger_register: Offset of the Trigger setup register
+ * @mr_prescal_mask: Mask of the PRESCAL field in the adc MR register
+ * @mr_startup_mask: Mask of the STARTUP field in the adc MR register
+ */
+struct at91_adc_reg_desc {
+ u8 channel_base;
+ u32 drdy_mask;
+ u8 status_register;
+ u8 trigger_register;
+ u32 mr_prescal_mask;
+ u32 mr_startup_mask;
+};
+
+struct at91_adc_caps {
+ bool has_ts; /* Support touch screen */
+ bool has_tsmr; /* only at91sam9x5, sama5d3 have TSMR reg */
+ /*
+ * Numbers of sampling data will be averaged. Can be 0~3.
+ * Hardware can average (2 ^ ts_filter_average) sample data.
+ */
+ u8 ts_filter_average;
+ /* Pen Detection input pull-up resistor, can be 0~3 */
+ u8 ts_pen_detect_sensitivity;
+
+ /* startup time calculate function */
+ u32 (*calc_startup_ticks)(u8 startup_time, u32 adc_clk_khz);
+
+ u8 num_channels;
+ struct at91_adc_reg_desc registers;
+};
+
+struct at91_adc_state {
+ struct clk *adc_clk;
+ u16 *buffer;
+ unsigned long channels_mask;
+ struct clk *clk;
+ bool done;
+ int irq;
+ u16 last_value;
+ int chnb;
+ struct mutex lock;
+ u8 num_channels;
+ void __iomem *reg_base;
+ struct at91_adc_reg_desc *registers;
+ u8 startup_time;
+ u8 sample_hold_time;
+ bool sleep_mode;
+ struct iio_trigger **trig;
+ struct at91_adc_trigger *trigger_list;
+ u32 trigger_number;
+ bool use_external;
+ u32 vref_mv;
+ u32 res; /* resolution used for convertions */
+ bool low_res; /* the resolution corresponds to the lowest one */
+ wait_queue_head_t wq_data_avail;
+ struct at91_adc_caps *caps;
+
+ /*
+ * Following ADC channels are shared by touchscreen:
+ *
+ * CH0 -- Touch screen XP/UL
+ * CH1 -- Touch screen XM/UR
+ * CH2 -- Touch screen YP/LL
+ * CH3 -- Touch screen YM/Sense
+ * CH4 -- Touch screen LR(5-wire only)
+ *
+ * The bitfields below represents the reserved channel in the
+ * touchscreen mode.
+ */
+#define CHAN_MASK_TOUCHSCREEN_4WIRE (0xf << 0)
+#define CHAN_MASK_TOUCHSCREEN_5WIRE (0x1f << 0)
+ enum atmel_adc_ts_type touchscreen_type;
+ struct input_dev *ts_input;
+
+ u16 ts_sample_period_val;
+ u32 ts_pressure_threshold;
+ u16 ts_pendbc;
+
+ bool ts_bufferedmeasure;
+ u32 ts_prev_absx;
+ u32 ts_prev_absy;
+};
+
+static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *idev = pf->indio_dev;
+ struct at91_adc_state *st = iio_priv(idev);
+ int i, j = 0;
+
+ for (i = 0; i < idev->masklength; i++) {
+ if (!test_bit(i, idev->active_scan_mask))
+ continue;
+ st->buffer[j] = at91_adc_readl(st, AT91_ADC_CHAN(st, i));
+ j++;
+ }
+
+ iio_push_to_buffers_with_timestamp(idev, st->buffer, pf->timestamp);
+
+ iio_trigger_notify_done(idev->trig);
+
+ /* Needed to ACK the DRDY interruption */
+ at91_adc_readl(st, AT91_ADC_LCDR);
+
+ enable_irq(st->irq);
+
+ return IRQ_HANDLED;
+}
+
+/* Handler for classic adc channel eoc trigger */
+static void handle_adc_eoc_trigger(int irq, struct iio_dev *idev)
+{
+ struct at91_adc_state *st = iio_priv(idev);
+
+ if (iio_buffer_enabled(idev)) {
+ disable_irq_nosync(irq);
+ iio_trigger_poll(idev->trig);
+ } else {
+ st->last_value = at91_adc_readl(st, AT91_ADC_CHAN(st, st->chnb));
+ st->done = true;
+ wake_up_interruptible(&st->wq_data_avail);
+ }
+}
+
+static int at91_ts_sample(struct at91_adc_state *st)
+{
+ unsigned int xscale, yscale, reg, z1, z2;
+ unsigned int x, y, pres, xpos, ypos;
+ unsigned int rxp = 1;
+ unsigned int factor = 1000;
+ struct iio_dev *idev = iio_priv_to_dev(st);
+
+ unsigned int xyz_mask_bits = st->res;
+ unsigned int xyz_mask = (1 << xyz_mask_bits) - 1;
+
+ /* calculate position */
+ /* x position = (x / xscale) * max, max = 2^MAX_POS_BITS - 1 */
+ reg = at91_adc_readl(st, AT91_ADC_TSXPOSR);
+ xpos = reg & xyz_mask;
+ x = (xpos << MAX_POS_BITS) - xpos;
+ xscale = (reg >> 16) & xyz_mask;
+ if (xscale == 0) {
+ dev_err(&idev->dev, "Error: xscale == 0!\n");
+ return -1;
+ }
+ x /= xscale;
+
+ /* y position = (y / yscale) * max, max = 2^MAX_POS_BITS - 1 */
+ reg = at91_adc_readl(st, AT91_ADC_TSYPOSR);
+ ypos = reg & xyz_mask;
+ y = (ypos << MAX_POS_BITS) - ypos;
+ yscale = (reg >> 16) & xyz_mask;
+ if (yscale == 0) {
+ dev_err(&idev->dev, "Error: yscale == 0!\n");
+ return -1;
+ }
+ y /= yscale;
+
+ /* calculate the pressure */
+ reg = at91_adc_readl(st, AT91_ADC_TSPRESSR);
+ z1 = reg & xyz_mask;
+ z2 = (reg >> 16) & xyz_mask;
+
+ if (z1 != 0)
+ pres = rxp * (x * factor / 1024) * (z2 * factor / z1 - factor)
+ / factor;
+ else
+ pres = st->ts_pressure_threshold; /* no pen contacted */
+
+ dev_dbg(&idev->dev, "xpos = %d, xscale = %d, ypos = %d, yscale = %d, z1 = %d, z2 = %d, press = %d\n",
+ xpos, xscale, ypos, yscale, z1, z2, pres);
+
+ if (pres < st->ts_pressure_threshold) {
+ dev_dbg(&idev->dev, "x = %d, y = %d, pressure = %d\n",
+ x, y, pres / factor);
+ input_report_abs(st->ts_input, ABS_X, x);
+ input_report_abs(st->ts_input, ABS_Y, y);
+ input_report_abs(st->ts_input, ABS_PRESSURE, pres);
+ input_report_key(st->ts_input, BTN_TOUCH, 1);
+ input_sync(st->ts_input);
+ } else {
+ dev_dbg(&idev->dev, "pressure too low: not reporting\n");
+ }
+
+ return 0;
+}
+
+static irqreturn_t at91_adc_rl_interrupt(int irq, void *private)
+{
+ struct iio_dev *idev = private;
+ struct at91_adc_state *st = iio_priv(idev);
+ u32 status = at91_adc_readl(st, st->registers->status_register);
+ unsigned int reg;
+
+ status &= at91_adc_readl(st, AT91_ADC_IMR);
+ if (status & GENMASK(st->num_channels - 1, 0))
+ handle_adc_eoc_trigger(irq, idev);
+
+ if (status & AT91RL_ADC_IER_PEN) {
+ /* Disabling pen debounce is required to get a NOPEN irq */
+ reg = at91_adc_readl(st, AT91_ADC_MR);
+ reg &= ~AT91_ADC_PENDBC;
+ at91_adc_writel(st, AT91_ADC_MR, reg);
+
+ at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_PEN);
+ at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_NOPEN
+ | AT91_ADC_EOC(3));
+ /* Set up period trigger for sampling */
+ at91_adc_writel(st, st->registers->trigger_register,
+ AT91_ADC_TRGR_MOD_PERIOD_TRIG |
+ AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val));
+ } else if (status & AT91RL_ADC_IER_NOPEN) {
+ reg = at91_adc_readl(st, AT91_ADC_MR);
+ reg |= AT91_ADC_PENDBC_(st->ts_pendbc) & AT91_ADC_PENDBC;
+ at91_adc_writel(st, AT91_ADC_MR, reg);
+ at91_adc_writel(st, st->registers->trigger_register,
+ AT91_ADC_TRGR_NONE);
+
+ at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_NOPEN
+ | AT91_ADC_EOC(3));
+ at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_PEN);
+ st->ts_bufferedmeasure = false;
+ input_report_key(st->ts_input, BTN_TOUCH, 0);
+ input_sync(st->ts_input);
+ } else if (status & AT91_ADC_EOC(3)) {
+ /* Conversion finished */
+ if (st->ts_bufferedmeasure) {
+ /*
+ * Last measurement is always discarded, since it can
+ * be erroneous.
+ * Always report previous measurement
+ */
+ input_report_abs(st->ts_input, ABS_X, st->ts_prev_absx);
+ input_report_abs(st->ts_input, ABS_Y, st->ts_prev_absy);
+ input_report_key(st->ts_input, BTN_TOUCH, 1);
+ input_sync(st->ts_input);
+ } else
+ st->ts_bufferedmeasure = true;
+
+ /* Now make new measurement */
+ st->ts_prev_absx = at91_adc_readl(st, AT91_ADC_CHAN(st, 3))
+ << MAX_RLPOS_BITS;
+ st->ts_prev_absx /= at91_adc_readl(st, AT91_ADC_CHAN(st, 2));
+
+ st->ts_prev_absy = at91_adc_readl(st, AT91_ADC_CHAN(st, 1))
+ << MAX_RLPOS_BITS;
+ st->ts_prev_absy /= at91_adc_readl(st, AT91_ADC_CHAN(st, 0));
+ }
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t at91_adc_9x5_interrupt(int irq, void *private)
+{
+ struct iio_dev *idev = private;
+ struct at91_adc_state *st = iio_priv(idev);
+ u32 status = at91_adc_readl(st, st->registers->status_register);
+ const uint32_t ts_data_irq_mask =
+ AT91_ADC_IER_XRDY |
+ AT91_ADC_IER_YRDY |
+ AT91_ADC_IER_PRDY;
+
+ if (status & GENMASK(st->num_channels - 1, 0))
+ handle_adc_eoc_trigger(irq, idev);
+
+ if (status & AT91_ADC_IER_PEN) {
+ at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
+ at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_NOPEN |
+ ts_data_irq_mask);
+ /* Set up period trigger for sampling */
+ at91_adc_writel(st, st->registers->trigger_register,
+ AT91_ADC_TRGR_MOD_PERIOD_TRIG |
+ AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val));
+ } else if (status & AT91_ADC_IER_NOPEN) {
+ at91_adc_writel(st, st->registers->trigger_register, 0);
+ at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_NOPEN |
+ ts_data_irq_mask);
+ at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
+
+ input_report_key(st->ts_input, BTN_TOUCH, 0);
+ input_sync(st->ts_input);
+ } else if ((status & ts_data_irq_mask) == ts_data_irq_mask) {
+ /* Now all touchscreen data is ready */
+
+ if (status & AT91_ADC_ISR_PENS) {
+ /* validate data by pen contact */
+ at91_ts_sample(st);
+ } else {
+ /* triggered by event that is no pen contact, just read
+ * them to clean the interrupt and discard all.
+ */
+ at91_adc_readl(st, AT91_ADC_TSXPOSR);
+ at91_adc_readl(st, AT91_ADC_TSYPOSR);
+ at91_adc_readl(st, AT91_ADC_TSPRESSR);
+ }
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int at91_adc_channel_init(struct iio_dev *idev)
+{
+ struct at91_adc_state *st = iio_priv(idev);
+ struct iio_chan_spec *chan_array, *timestamp;
+ int bit, idx = 0;
+ unsigned long rsvd_mask = 0;
+
+ /* If touchscreen is enable, then reserve the adc channels */
+ if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
+ rsvd_mask = CHAN_MASK_TOUCHSCREEN_4WIRE;
+ else if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_5WIRE)
+ rsvd_mask = CHAN_MASK_TOUCHSCREEN_5WIRE;
+
+ /* set up the channel mask to reserve touchscreen channels */
+ st->channels_mask &= ~rsvd_mask;
+
+ idev->num_channels = bitmap_weight(&st->channels_mask,
+ st->num_channels) + 1;
+
+ chan_array = devm_kzalloc(&idev->dev,
+ ((idev->num_channels + 1) *
+ sizeof(struct iio_chan_spec)),
+ GFP_KERNEL);
+
+ if (!chan_array)
+ return -ENOMEM;
+
+ for_each_set_bit(bit, &st->channels_mask, st->num_channels) {
+ struct iio_chan_spec *chan = chan_array + idx;
+
+ chan->type = IIO_VOLTAGE;
+ chan->indexed = 1;
+ chan->channel = bit;
+ chan->scan_index = idx;
+ chan->scan_type.sign = 'u';
+ chan->scan_type.realbits = st->res;
+ chan->scan_type.storagebits = 16;
+ chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
+ chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
+ idx++;
+ }
+ timestamp = chan_array + idx;
+
+ timestamp->type = IIO_TIMESTAMP;
+ timestamp->channel = -1;
+ timestamp->scan_index = idx;
+ timestamp->scan_type.sign = 's';
+ timestamp->scan_type.realbits = 64;
+ timestamp->scan_type.storagebits = 64;
+
+ idev->channels = chan_array;
+ return idev->num_channels;
+}
+
+static int at91_adc_get_trigger_value_by_name(struct iio_dev *idev,
+ struct at91_adc_trigger *triggers,
+ const char *trigger_name)
+{
+ struct at91_adc_state *st = iio_priv(idev);
+ int i;
+
+ for (i = 0; i < st->trigger_number; i++) {
+ char *name = kasprintf(GFP_KERNEL,
+ "%s-dev%d-%s",
+ idev->name,
+ idev->id,
+ triggers[i].name);
+ if (!name)
+ return -ENOMEM;
+
+ if (strcmp(trigger_name, name) == 0) {
+ kfree(name);
+ if (triggers[i].value == 0)
+ return -EINVAL;
+ return triggers[i].value;
+ }
+
+ kfree(name);
+ }
+
+ return -EINVAL;
+}
+
+static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
+{
+ struct iio_dev *idev = iio_trigger_get_drvdata(trig);
+ struct at91_adc_state *st = iio_priv(idev);
+ struct at91_adc_reg_desc *reg = st->registers;
+ u32 status = at91_adc_readl(st, reg->trigger_register);
+ int value;
+ u8 bit;
+
+ value = at91_adc_get_trigger_value_by_name(idev,
+ st->trigger_list,
+ idev->trig->name);
+ if (value < 0)
+ return value;
+
+ if (state) {
+ st->buffer = kmalloc(idev->scan_bytes, GFP_KERNEL);
+ if (st->buffer == NULL)
+ return -ENOMEM;
+
+ at91_adc_writel(st, reg->trigger_register,
+ status | value);
+
+ for_each_set_bit(bit, idev->active_scan_mask,
+ st->num_channels) {
+ struct iio_chan_spec const *chan = idev->channels + bit;
+ at91_adc_writel(st, AT91_ADC_CHER,
+ AT91_ADC_CH(chan->channel));
+ }
+
+ at91_adc_writel(st, AT91_ADC_IER, reg->drdy_mask);
+
+ } else {
+ at91_adc_writel(st, AT91_ADC_IDR, reg->drdy_mask);
+
+ at91_adc_writel(st, reg->trigger_register,
+ status & ~value);
+
+ for_each_set_bit(bit, idev->active_scan_mask,
+ st->num_channels) {
+ struct iio_chan_spec const *chan = idev->channels + bit;
+ at91_adc_writel(st, AT91_ADC_CHDR,
+ AT91_ADC_CH(chan->channel));
+ }
+ kfree(st->buffer);
+ }
+
+ return 0;
+}
+
+static const struct iio_trigger_ops at91_adc_trigger_ops = {
+ .owner = THIS_MODULE,
+ .set_trigger_state = &at91_adc_configure_trigger,
+};
+
+static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *idev,
+ struct at91_adc_trigger *trigger)
+{
+ struct iio_trigger *trig;
+ int ret;
+
+ trig = iio_trigger_alloc("%s-dev%d-%s", idev->name,
+ idev->id, trigger->name);
+ if (trig == NULL)
+ return NULL;
+
+ trig->dev.parent = idev->dev.parent;
+ iio_trigger_set_drvdata(trig, idev);
+ trig->ops = &at91_adc_trigger_ops;
+
+ ret = iio_trigger_register(trig);
+ if (ret)
+ return NULL;
+
+ return trig;
+}
+
+static int at91_adc_trigger_init(struct iio_dev *idev)
+{
+ struct at91_adc_state *st = iio_priv(idev);
+ int i, ret;
+
+ st->trig = devm_kzalloc(&idev->dev,
+ st->trigger_number * sizeof(*st->trig),
+ GFP_KERNEL);
+
+ if (st->trig == NULL) {
+ ret = -ENOMEM;
+ goto error_ret;
+ }
+
+ for (i = 0; i < st->trigger_number; i++) {
+ if (st->trigger_list[i].is_external && !(st->use_external))
+ continue;
+
+ st->trig[i] = at91_adc_allocate_trigger(idev,
+ st->trigger_list + i);
+ if (st->trig[i] == NULL) {
+ dev_err(&idev->dev,
+ "Could not allocate trigger %d\n", i);
+ ret = -ENOMEM;
+ goto error_trigger;
+ }
+ }
+
+ return 0;
+
+error_trigger:
+ for (i--; i >= 0; i--) {
+ iio_trigger_unregister(st->trig[i]);
+ iio_trigger_free(st->trig[i]);
+ }
+error_ret:
+ return ret;
+}
+
+static void at91_adc_trigger_remove(struct iio_dev *idev)
+{
+ struct at91_adc_state *st = iio_priv(idev);
+ int i;
+
+ for (i = 0; i < st->trigger_number; i++) {
+ iio_trigger_unregister(st->trig[i]);
+ iio_trigger_free(st->trig[i]);
+ }
+}
+
+static int at91_adc_buffer_init(struct iio_dev *idev)
+{
+ return iio_triggered_buffer_setup(idev, &iio_pollfunc_store_time,
+ &at91_adc_trigger_handler, NULL);
+}
+
+static void at91_adc_buffer_remove(struct iio_dev *idev)
+{
+ iio_triggered_buffer_cleanup(idev);
+}
+
+static int at91_adc_read_raw(struct iio_dev *idev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct at91_adc_state *st = iio_priv(idev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ mutex_lock(&st->lock);
+
+ st->chnb = chan->channel;
+ at91_adc_writel(st, AT91_ADC_CHER,
+ AT91_ADC_CH(chan->channel));
+ at91_adc_writel(st, AT91_ADC_IER, BIT(chan->channel));
+ at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_START);
+
+ ret = wait_event_interruptible_timeout(st->wq_data_avail,
+ st->done,
+ msecs_to_jiffies(1000));
+ if (ret == 0)
+ ret = -ETIMEDOUT;
+ if (ret < 0) {
+ mutex_unlock(&st->lock);
+ return ret;
+ }
+
+ *val = st->last_value;
+
+ at91_adc_writel(st, AT91_ADC_CHDR,
+ AT91_ADC_CH(chan->channel));
+ at91_adc_writel(st, AT91_ADC_IDR, BIT(chan->channel));
+
+ st->last_value = 0;
+ st->done = false;
+ mutex_unlock(&st->lock);
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ *val = st->vref_mv;
+ *val2 = chan->scan_type.realbits;
+ return IIO_VAL_FRACTIONAL_LOG2;
+ default:
+ break;
+ }
+ return -EINVAL;
+}
+
+static int at91_adc_of_get_resolution(struct at91_adc_state *st,
+ struct platform_device *pdev)
+{
+ struct iio_dev *idev = iio_priv_to_dev(st);
+ struct device_node *np = pdev->dev.of_node;
+ int count, i, ret = 0;
+ char *res_name, *s;
+ u32 *resolutions;
+
+ count = of_property_count_strings(np, "atmel,adc-res-names");
+ if (count < 2) {
+ dev_err(&idev->dev, "You must specified at least two resolution names for "
+ "adc-res-names property in the DT\n");
+ return count;
+ }
+
+ resolutions = kmalloc(count * sizeof(*resolutions), GFP_KERNEL);
+ if (!resolutions)
+ return -ENOMEM;
+
+ if (of_property_read_u32_array(np, "atmel,adc-res", resolutions, count)) {
+ dev_err(&idev->dev, "Missing adc-res property in the DT.\n");
+ ret = -ENODEV;
+ goto ret;
+ }
+
+ if (of_property_read_string(np, "atmel,adc-use-res", (const char **)&res_name))
+ res_name = "highres";
+
+ for (i = 0; i < count; i++) {
+ if (of_property_read_string_index(np, "atmel,adc-res-names", i, (const char **)&s))
+ continue;
+
+ if (strcmp(res_name, s))
+ continue;
+
+ st->res = resolutions[i];
+ if (!strcmp(res_name, "lowres"))
+ st->low_res = true;
+ else
+ st->low_res = false;
+
+ dev_info(&idev->dev, "Resolution used: %u bits\n", st->res);
+ goto ret;
+ }
+
+ dev_err(&idev->dev, "There is no resolution for %s\n", res_name);
+
+ret:
+ kfree(resolutions);
+ return ret;
+}
+
+static u32 calc_startup_ticks_9260(u8 startup_time, u32 adc_clk_khz)
+{
+ /*
+ * Number of ticks needed to cover the startup time of the ADC
+ * as defined in the electrical characteristics of the board,
+ * divided by 8. The formula thus is :
+ * Startup Time = (ticks + 1) * 8 / ADC Clock
+ */
+ return round_up((startup_time * adc_clk_khz / 1000) - 1, 8) / 8;
+}
+
+static u32 calc_startup_ticks_9x5(u8 startup_time, u32 adc_clk_khz)
+{
+ /*
+ * For sama5d3x and at91sam9x5, the formula changes to:
+ * Startup Time = <lookup_table_value> / ADC Clock
+ */
+ const int startup_lookup[] = {
+ 0 , 8 , 16 , 24 ,
+ 64 , 80 , 96 , 112,
+ 512, 576, 640, 704,
+ 768, 832, 896, 960
+ };
+ int i, size = ARRAY_SIZE(startup_lookup);
+ unsigned int ticks;
+
+ ticks = startup_time * adc_clk_khz / 1000;
+ for (i = 0; i < size; i++)
+ if (ticks < startup_lookup[i])
+ break;
+
+ ticks = i;
+ if (ticks == size)
+ /* Reach the end of lookup table */
+ ticks = size - 1;
+
+ return ticks;
+}
+
+static const struct of_device_id at91_adc_dt_ids[];
+
+static int at91_adc_probe_dt_ts(struct device_node *node,
+ struct at91_adc_state *st, struct device *dev)
+{
+ int ret;
+ u32 prop;
+
+ ret = of_property_read_u32(node, "atmel,adc-ts-wires", &prop);
+ if (ret) {
+ dev_info(dev, "ADC Touch screen is disabled.\n");
+ return 0;
+ }
+
+ switch (prop) {
+ case 4:
+ case 5:
+ st->touchscreen_type = prop;
+ break;
+ default:
+ dev_err(dev, "Unsupported number of touchscreen wires (%d). Should be 4 or 5.\n", prop);
+ return -EINVAL;
+ }
+
+ if (!st->caps->has_tsmr)
+ return 0;
+ prop = 0;
+ of_property_read_u32(node, "atmel,adc-ts-pressure-threshold", &prop);
+ st->ts_pressure_threshold = prop;
+ if (st->ts_pressure_threshold) {
+ return 0;
+ } else {
+ dev_err(dev, "Invalid pressure threshold for the touchscreen\n");
+ return -EINVAL;
+ }
+}
+
+static int at91_adc_probe_dt(struct at91_adc_state *st,
+ struct platform_device *pdev)
+{
+ struct iio_dev *idev = iio_priv_to_dev(st);
+ struct device_node *node = pdev->dev.of_node;
+ struct device_node *trig_node;
+ int i = 0, ret;
+ u32 prop;
+
+ if (!node)
+ return -EINVAL;
+
+ st->caps = (struct at91_adc_caps *)
+ of_match_device(at91_adc_dt_ids, &pdev->dev)->data;
+
+ st->use_external = of_property_read_bool(node, "atmel,adc-use-external-triggers");
+
+ if (of_property_read_u32(node, "atmel,adc-channels-used", &prop)) {
+ dev_err(&idev->dev, "Missing adc-channels-used property in the DT.\n");
+ ret = -EINVAL;
+ goto error_ret;
+ }
+ st->channels_mask = prop;
+
+ st->sleep_mode = of_property_read_bool(node, "atmel,adc-sleep-mode");
+
+ if (of_property_read_u32(node, "atmel,adc-startup-time", &prop)) {
+ dev_err(&idev->dev, "Missing adc-startup-time property in the DT.\n");
+ ret = -EINVAL;
+ goto error_ret;
+ }
+ st->startup_time = prop;
+
+ prop = 0;
+ of_property_read_u32(node, "atmel,adc-sample-hold-time", &prop);
+ st->sample_hold_time = prop;
+
+ if (of_property_read_u32(node, "atmel,adc-vref", &prop)) {
+ dev_err(&idev->dev, "Missing adc-vref property in the DT.\n");
+ ret = -EINVAL;
+ goto error_ret;
+ }
+ st->vref_mv = prop;
+
+ ret = at91_adc_of_get_resolution(st, pdev);
+ if (ret)
+ goto error_ret;
+
+ st->registers = &st->caps->registers;
+ st->num_channels = st->caps->num_channels;
+ st->trigger_number = of_get_child_count(node);
+ st->trigger_list = devm_kzalloc(&idev->dev, st->trigger_number *
+ sizeof(struct at91_adc_trigger),
+ GFP_KERNEL);
+ if (!st->trigger_list) {
+ dev_err(&idev->dev, "Could not allocate trigger list memory.\n");
+ ret = -ENOMEM;
+ goto error_ret;
+ }
+
+ for_each_child_of_node(node, trig_node) {
+ struct at91_adc_trigger *trig = st->trigger_list + i;
+ const char *name;
+
+ if (of_property_read_string(trig_node, "trigger-name", &name)) {
+ dev_err(&idev->dev, "Missing trigger-name property in the DT.\n");
+ ret = -EINVAL;
+ goto error_ret;
+ }
+ trig->name = name;
+
+ if (of_property_read_u32(trig_node, "trigger-value", &prop)) {
+ dev_err(&idev->dev, "Missing trigger-value property in the DT.\n");
+ ret = -EINVAL;
+ goto error_ret;
+ }
+ trig->value = prop;
+ trig->is_external = of_property_read_bool(trig_node, "trigger-external");
+ i++;
+ }
+
+ /* Check if touchscreen is supported. */
+ if (st->caps->has_ts)
+ return at91_adc_probe_dt_ts(node, st, &idev->dev);
+ else
+ dev_info(&idev->dev, "not support touchscreen in the adc compatible string.\n");
+
+ return 0;
+
+error_ret:
+ return ret;
+}
+
+static int at91_adc_probe_pdata(struct at91_adc_state *st,
+ struct platform_device *pdev)
+{
+ struct at91_adc_data *pdata = pdev->dev.platform_data;
+
+ if (!pdata)
+ return -EINVAL;
+
+ st->caps = (struct at91_adc_caps *)
+ platform_get_device_id(pdev)->driver_data;
+
+ st->use_external = pdata->use_external_triggers;
+ st->vref_mv = pdata->vref;
+ st->channels_mask = pdata->channels_used;
+ st->num_channels = st->caps->num_channels;
+ st->startup_time = pdata->startup_time;
+ st->trigger_number = pdata->trigger_number;
+ st->trigger_list = pdata->trigger_list;
+ st->registers = &st->caps->registers;
+ st->touchscreen_type = pdata->touchscreen_type;
+
+ return 0;
+}
+
+static const struct iio_info at91_adc_info = {
+ .driver_module = THIS_MODULE,
+ .read_raw = &at91_adc_read_raw,
+};
+
+/* Touchscreen related functions */
+static int atmel_ts_open(struct input_dev *dev)
+{
+ struct at91_adc_state *st = input_get_drvdata(dev);
+
+ if (st->caps->has_tsmr)
+ at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
+ else
+ at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_PEN);
+ return 0;
+}
+
+static void atmel_ts_close(struct input_dev *dev)
+{
+ struct at91_adc_state *st = input_get_drvdata(dev);
+
+ if (st->caps->has_tsmr)
+ at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
+ else
+ at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_PEN);
+}
+
+static int at91_ts_hw_init(struct at91_adc_state *st, u32 adc_clk_khz)
+{
+ u32 reg = 0;
+ int i = 0;
+
+ /* a Pen Detect Debounce Time is necessary for the ADC Touch to avoid
+ * pen detect noise.
+ * The formula is : Pen Detect Debounce Time = (2 ^ pendbc) / ADCClock
+ */
+ st->ts_pendbc = round_up(TOUCH_PEN_DETECT_DEBOUNCE_US * adc_clk_khz /
+ 1000, 1);
+
+ while (st->ts_pendbc >> ++i)
+ ; /* Empty! Find the shift offset */
+ if (abs(st->ts_pendbc - (1 << i)) < abs(st->ts_pendbc - (1 << (i - 1))))
+ st->ts_pendbc = i;
+ else
+ st->ts_pendbc = i - 1;
+
+ if (!st->caps->has_tsmr) {
+ reg = at91_adc_readl(st, AT91_ADC_MR);
+ reg |= AT91_ADC_TSAMOD_TS_ONLY_MODE | AT91_ADC_PENDET;
+
+ reg |= AT91_ADC_PENDBC_(st->ts_pendbc) & AT91_ADC_PENDBC;
+ at91_adc_writel(st, AT91_ADC_MR, reg);
+
+ reg = AT91_ADC_TSR_SHTIM_(TOUCH_SHTIM) & AT91_ADC_TSR_SHTIM;
+ at91_adc_writel(st, AT91_ADC_TSR, reg);
+
+ st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US_RL *
+ adc_clk_khz / 1000) - 1, 1);
+
+ return 0;
+ }
+
+ if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
+ reg = AT91_ADC_TSMR_TSMODE_4WIRE_PRESS;
+ else
+ reg = AT91_ADC_TSMR_TSMODE_5WIRE;
+
+ reg |= AT91_ADC_TSMR_TSAV_(st->caps->ts_filter_average)
+ & AT91_ADC_TSMR_TSAV;
+ reg |= AT91_ADC_TSMR_PENDBC_(st->ts_pendbc) & AT91_ADC_TSMR_PENDBC;
+ reg |= AT91_ADC_TSMR_NOTSDMA;
+ reg |= AT91_ADC_TSMR_PENDET_ENA;
+ reg |= 0x03 << 8; /* TSFREQ, needs to be bigger than TSAV */
+
+ at91_adc_writel(st, AT91_ADC_TSMR, reg);
+
+ /* Change adc internal resistor value for better pen detection,
+ * default value is 100 kOhm.
+ * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm
+ * option only available on ES2 and higher
+ */
+ at91_adc_writel(st, AT91_ADC_ACR, st->caps->ts_pen_detect_sensitivity
+ & AT91_ADC_ACR_PENDETSENS);
+
+ /* Sample Period Time = (TRGPER + 1) / ADCClock */
+ st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US *
+ adc_clk_khz / 1000) - 1, 1);
+
+ return 0;
+}
+
+static int at91_ts_register(struct at91_adc_state *st,
+ struct platform_device *pdev)
+{
+ struct input_dev *input;
+ struct iio_dev *idev = iio_priv_to_dev(st);
+ int ret;
+
+ input = input_allocate_device();
+ if (!input) {
+ dev_err(&idev->dev, "Failed to allocate TS device!\n");
+ return -ENOMEM;
+ }
+
+ input->name = DRIVER_NAME;
+ input->id.bustype = BUS_HOST;
+ input->dev.parent = &pdev->dev;
+ input->open = atmel_ts_open;
+ input->close = atmel_ts_close;
+
+ __set_bit(EV_ABS, input->evbit);
+ __set_bit(EV_KEY, input->evbit);
+ __set_bit(BTN_TOUCH, input->keybit);
+ if (st->caps->has_tsmr) {
+ input_set_abs_params(input, ABS_X, 0, (1 << MAX_POS_BITS) - 1,
+ 0, 0);
+ input_set_abs_params(input, ABS_Y, 0, (1 << MAX_POS_BITS) - 1,
+ 0, 0);
+ input_set_abs_params(input, ABS_PRESSURE, 0, 0xffffff, 0, 0);
+ } else {
+ if (st->touchscreen_type != ATMEL_ADC_TOUCHSCREEN_4WIRE) {
+ dev_err(&pdev->dev,
+ "This touchscreen controller only support 4 wires\n");
+ ret = -EINVAL;
+ goto err;
+ }
+
+ input_set_abs_params(input, ABS_X, 0, (1 << MAX_RLPOS_BITS) - 1,
+ 0, 0);
+ input_set_abs_params(input, ABS_Y, 0, (1 << MAX_RLPOS_BITS) - 1,
+ 0, 0);
+ }
+
+ st->ts_input = input;
+ input_set_drvdata(input, st);
+
+ ret = input_register_device(input);
+ if (ret)
+ goto err;
+
+ return ret;
+
+err:
+ input_free_device(st->ts_input);
+ return ret;
+}
+
+static void at91_ts_unregister(struct at91_adc_state *st)
+{
+ input_unregister_device(st->ts_input);
+}
+
+static int at91_adc_probe(struct platform_device *pdev)
+{
+ unsigned int prsc, mstrclk, ticks, adc_clk, adc_clk_khz, shtim;
+ int ret;
+ struct iio_dev *idev;
+ struct at91_adc_state *st;
+ struct resource *res;
+ u32 reg;
+
+ idev = devm_iio_device_alloc(&pdev->dev, sizeof(struct at91_adc_state));
+ if (!idev)
+ return -ENOMEM;
+
+ st = iio_priv(idev);
+
+ if (pdev->dev.of_node)
+ ret = at91_adc_probe_dt(st, pdev);
+ else
+ ret = at91_adc_probe_pdata(st, pdev);
+
+ if (ret) {
+ dev_err(&pdev->dev, "No platform data available.\n");
+ return -EINVAL;
+ }
+
+ platform_set_drvdata(pdev, idev);
+
+ idev->dev.parent = &pdev->dev;
+ idev->name = dev_name(&pdev->dev);
+ idev->modes = INDIO_DIRECT_MODE;
+ idev->info = &at91_adc_info;
+
+ st->irq = platform_get_irq(pdev, 0);
+ if (st->irq < 0) {
+ dev_err(&pdev->dev, "No IRQ ID is designated\n");
+ return -ENODEV;
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+ st->reg_base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(st->reg_base)) {
+ return PTR_ERR(st->reg_base);
+ }
+
+ /*
+ * Disable all IRQs before setting up the handler
+ */
+ at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_SWRST);
+ at91_adc_writel(st, AT91_ADC_IDR, 0xFFFFFFFF);
+
+ if (st->caps->has_tsmr)
+ ret = request_irq(st->irq, at91_adc_9x5_interrupt, 0,
+ pdev->dev.driver->name, idev);
+ else
+ ret = request_irq(st->irq, at91_adc_rl_interrupt, 0,
+ pdev->dev.driver->name, idev);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to allocate IRQ.\n");
+ return ret;
+ }
+
+ st->clk = devm_clk_get(&pdev->dev, "adc_clk");
+ if (IS_ERR(st->clk)) {
+ dev_err(&pdev->dev, "Failed to get the clock.\n");
+ ret = PTR_ERR(st->clk);
+ goto error_free_irq;
+ }
+
+ ret = clk_prepare_enable(st->clk);
+ if (ret) {
+ dev_err(&pdev->dev,
+ "Could not prepare or enable the clock.\n");
+ goto error_free_irq;
+ }
+
+ st->adc_clk = devm_clk_get(&pdev->dev, "adc_op_clk");
+ if (IS_ERR(st->adc_clk)) {
+ dev_err(&pdev->dev, "Failed to get the ADC clock.\n");
+ ret = PTR_ERR(st->adc_clk);
+ goto error_disable_clk;
+ }
+
+ ret = clk_prepare_enable(st->adc_clk);
+ if (ret) {
+ dev_err(&pdev->dev,
+ "Could not prepare or enable the ADC clock.\n");
+ goto error_disable_clk;
+ }
+
+ /*
+ * Prescaler rate computation using the formula from the Atmel's
+ * datasheet : ADC Clock = MCK / ((Prescaler + 1) * 2), ADC Clock being
+ * specified by the electrical characteristics of the board.
+ */
+ mstrclk = clk_get_rate(st->clk);
+ adc_clk = clk_get_rate(st->adc_clk);
+ adc_clk_khz = adc_clk / 1000;
+
+ dev_dbg(&pdev->dev, "Master clock is set as: %d Hz, adc_clk should set as: %d Hz\n",
+ mstrclk, adc_clk);
+
+ prsc = (mstrclk / (2 * adc_clk)) - 1;
+
+ if (!st->startup_time) {
+ dev_err(&pdev->dev, "No startup time available.\n");
+ ret = -EINVAL;
+ goto error_disable_adc_clk;
+ }
+ ticks = (*st->caps->calc_startup_ticks)(st->startup_time, adc_clk_khz);
+
+ /*
+ * a minimal Sample and Hold Time is necessary for the ADC to guarantee
+ * the best converted final value between two channels selection
+ * The formula thus is : Sample and Hold Time = (shtim + 1) / ADCClock
+ */
+ if (st->sample_hold_time > 0)
+ shtim = round_up((st->sample_hold_time * adc_clk_khz / 1000)
+ - 1, 1);
+ else
+ shtim = 0;
+
+ reg = AT91_ADC_PRESCAL_(prsc) & st->registers->mr_prescal_mask;
+ reg |= AT91_ADC_STARTUP_(ticks) & st->registers->mr_startup_mask;
+ if (st->low_res)
+ reg |= AT91_ADC_LOWRES;
+ if (st->sleep_mode)
+ reg |= AT91_ADC_SLEEP;
+ reg |= AT91_ADC_SHTIM_(shtim) & AT91_ADC_SHTIM;
+ at91_adc_writel(st, AT91_ADC_MR, reg);
+
+ /* Setup the ADC channels available on the board */
+ ret = at91_adc_channel_init(idev);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Couldn't initialize the channels.\n");
+ goto error_disable_adc_clk;
+ }
+
+ init_waitqueue_head(&st->wq_data_avail);
+ mutex_init(&st->lock);
+
+ /*
+ * Since touch screen will set trigger register as period trigger. So
+ * when touch screen is enabled, then we have to disable hardware
+ * trigger for classic adc.
+ */
+ if (!st->touchscreen_type) {
+ ret = at91_adc_buffer_init(idev);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Couldn't initialize the buffer.\n");
+ goto error_disable_adc_clk;
+ }
+
+ ret = at91_adc_trigger_init(idev);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Couldn't setup the triggers.\n");
+ at91_adc_buffer_remove(idev);
+ goto error_disable_adc_clk;
+ }
+ } else {
+ ret = at91_ts_register(st, pdev);
+ if (ret)
+ goto error_disable_adc_clk;
+
+ at91_ts_hw_init(st, adc_clk_khz);
+ }
+
+ ret = iio_device_register(idev);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Couldn't register the device.\n");
+ goto error_iio_device_register;
+ }
+
+ return 0;
+
+error_iio_device_register:
+ if (!st->touchscreen_type) {
+ at91_adc_trigger_remove(idev);
+ at91_adc_buffer_remove(idev);
+ } else {
+ at91_ts_unregister(st);
+ }
+error_disable_adc_clk:
+ clk_disable_unprepare(st->adc_clk);
+error_disable_clk:
+ clk_disable_unprepare(st->clk);
+error_free_irq:
+ free_irq(st->irq, idev);
+ return ret;
+}
+
+static int at91_adc_remove(struct platform_device *pdev)
+{
+ struct iio_dev *idev = platform_get_drvdata(pdev);
+ struct at91_adc_state *st = iio_priv(idev);
+
+ iio_device_unregister(idev);
+ if (!st->touchscreen_type) {
+ at91_adc_trigger_remove(idev);
+ at91_adc_buffer_remove(idev);
+ } else {
+ at91_ts_unregister(st);
+ }
+ clk_disable_unprepare(st->adc_clk);
+ clk_disable_unprepare(st->clk);
+ free_irq(st->irq, idev);
+
+ return 0;
+}
+
+static struct at91_adc_caps at91sam9260_caps = {
+ .calc_startup_ticks = calc_startup_ticks_9260,
+ .num_channels = 4,
+ .registers = {
+ .channel_base = AT91_ADC_CHR(0),
+ .drdy_mask = AT91_ADC_DRDY,
+ .status_register = AT91_ADC_SR,
+ .trigger_register = AT91_ADC_TRGR_9260,
+ .mr_prescal_mask = AT91_ADC_PRESCAL_9260,
+ .mr_startup_mask = AT91_ADC_STARTUP_9260,
+ },
+};
+
+static struct at91_adc_caps at91sam9rl_caps = {
+ .has_ts = true,
+ .calc_startup_ticks = calc_startup_ticks_9260, /* same as 9260 */
+ .num_channels = 6,
+ .registers = {
+ .channel_base = AT91_ADC_CHR(0),
+ .drdy_mask = AT91_ADC_DRDY,
+ .status_register = AT91_ADC_SR,
+ .trigger_register = AT91_ADC_TRGR_9G45,
+ .mr_prescal_mask = AT91_ADC_PRESCAL_9260,
+ .mr_startup_mask = AT91_ADC_STARTUP_9G45,
+ },
+};
+
+static struct at91_adc_caps at91sam9g45_caps = {
+ .has_ts = true,
+ .calc_startup_ticks = calc_startup_ticks_9260, /* same as 9260 */
+ .num_channels = 8,
+ .registers = {
+ .channel_base = AT91_ADC_CHR(0),
+ .drdy_mask = AT91_ADC_DRDY,
+ .status_register = AT91_ADC_SR,
+ .trigger_register = AT91_ADC_TRGR_9G45,
+ .mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
+ .mr_startup_mask = AT91_ADC_STARTUP_9G45,
+ },
+};
+
+static struct at91_adc_caps at91sam9x5_caps = {
+ .has_ts = true,
+ .has_tsmr = true,
+ .ts_filter_average = 3,
+ .ts_pen_detect_sensitivity = 2,
+ .calc_startup_ticks = calc_startup_ticks_9x5,
+ .num_channels = 12,
+ .registers = {
+ .channel_base = AT91_ADC_CDR0_9X5,
+ .drdy_mask = AT91_ADC_SR_DRDY_9X5,
+ .status_register = AT91_ADC_SR_9X5,
+ .trigger_register = AT91_ADC_TRGR_9X5,
+ /* prescal mask is same as 9G45 */
+ .mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
+ .mr_startup_mask = AT91_ADC_STARTUP_9X5,
+ },
+};
+
+static const struct of_device_id at91_adc_dt_ids[] = {
+ { .compatible = "atmel,at91sam9260-adc", .data = &at91sam9260_caps },
+ { .compatible = "atmel,at91sam9rl-adc", .data = &at91sam9rl_caps },
+ { .compatible = "atmel,at91sam9g45-adc", .data = &at91sam9g45_caps },
+ { .compatible = "atmel,at91sam9x5-adc", .data = &at91sam9x5_caps },
+ {},
+};
+MODULE_DEVICE_TABLE(of, at91_adc_dt_ids);
+
+static const struct platform_device_id at91_adc_ids[] = {
+ {
+ .name = "at91sam9260-adc",
+ .driver_data = (unsigned long)&at91sam9260_caps,
+ }, {
+ .name = "at91sam9rl-adc",
+ .driver_data = (unsigned long)&at91sam9rl_caps,
+ }, {
+ .name = "at91sam9g45-adc",
+ .driver_data = (unsigned long)&at91sam9g45_caps,
+ }, {
+ .name = "at91sam9x5-adc",
+ .driver_data = (unsigned long)&at91sam9x5_caps,
+ }, {
+ /* terminator */
+ }
+};
+MODULE_DEVICE_TABLE(platform, at91_adc_ids);
+
+static struct platform_driver at91_adc_driver = {
+ .probe = at91_adc_probe,
+ .remove = at91_adc_remove,
+ .id_table = at91_adc_ids,
+ .driver = {
+ .name = DRIVER_NAME,
+ .of_match_table = of_match_ptr(at91_adc_dt_ids),
+ },
+};
+
+module_platform_driver(at91_adc_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Atmel AT91 ADC Driver");
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
Code Review / kvmfornfv.git / blobdiff