| /* |
| * Freescale i.MX28 LRADC driver |
| * |
| * Copyright (c) 2012 DENX Software Engineering, GmbH. |
| * Marek Vasut <marex@denx.de> |
| * |
| * 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; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * 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. |
| */ |
| |
| #include <linux/err.h> |
| #include <linux/interrupt.h> |
| #include <linux/device.h> |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/of.h> |
| #include <linux/of_device.h> |
| #include <linux/sysfs.h> |
| #include <linux/list.h> |
| #include <linux/io.h> |
| #include <linux/module.h> |
| #include <linux/platform_device.h> |
| #include <linux/spinlock.h> |
| #include <linux/wait.h> |
| #include <linux/sched.h> |
| #include <linux/stmp_device.h> |
| #include <linux/bitops.h> |
| #include <linux/completion.h> |
| #include <linux/delay.h> |
| #include <linux/input.h> |
| #include <linux/clk.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> |
| |
| #define DRIVER_NAME "mxs-lradc" |
| |
| #define LRADC_MAX_DELAY_CHANS 4 |
| #define LRADC_MAX_MAPPED_CHANS 8 |
| #define LRADC_MAX_TOTAL_CHANS 16 |
| |
| #define LRADC_DELAY_TIMER_HZ 2000 |
| |
| /* |
| * Make this runtime configurable if necessary. Currently, if the buffered mode |
| * is enabled, the LRADC takes LRADC_DELAY_TIMER_LOOP samples of data before |
| * triggering IRQ. The sampling happens every (LRADC_DELAY_TIMER_PER / 2000) |
| * seconds. The result is that the samples arrive every 500mS. |
| */ |
| #define LRADC_DELAY_TIMER_PER 200 |
| #define LRADC_DELAY_TIMER_LOOP 5 |
| |
| /* |
| * Once the pen touches the touchscreen, the touchscreen switches from |
| * IRQ-driven mode to polling mode to prevent interrupt storm. The polling |
| * is realized by worker thread, which is called every 20 or so milliseconds. |
| * This gives the touchscreen enough fluence and does not strain the system |
| * too much. |
| */ |
| #define LRADC_TS_SAMPLE_DELAY_MS 5 |
| |
| /* |
| * The LRADC reads the following amount of samples from each touchscreen |
| * channel and the driver then computes avarage of these. |
| */ |
| #define LRADC_TS_SAMPLE_AMOUNT 4 |
| |
| enum mxs_lradc_id { |
| IMX23_LRADC, |
| IMX28_LRADC, |
| }; |
| |
| static const char * const mx23_lradc_irq_names[] = { |
| "mxs-lradc-touchscreen", |
| "mxs-lradc-channel0", |
| "mxs-lradc-channel1", |
| "mxs-lradc-channel2", |
| "mxs-lradc-channel3", |
| "mxs-lradc-channel4", |
| "mxs-lradc-channel5", |
| "mxs-lradc-channel6", |
| "mxs-lradc-channel7", |
| }; |
| |
| static const char * const mx28_lradc_irq_names[] = { |
| "mxs-lradc-touchscreen", |
| "mxs-lradc-thresh0", |
| "mxs-lradc-thresh1", |
| "mxs-lradc-channel0", |
| "mxs-lradc-channel1", |
| "mxs-lradc-channel2", |
| "mxs-lradc-channel3", |
| "mxs-lradc-channel4", |
| "mxs-lradc-channel5", |
| "mxs-lradc-channel6", |
| "mxs-lradc-channel7", |
| "mxs-lradc-button0", |
| "mxs-lradc-button1", |
| }; |
| |
| struct mxs_lradc_of_config { |
| const int irq_count; |
| const char * const *irq_name; |
| }; |
| |
| static const struct mxs_lradc_of_config mxs_lradc_of_config[] = { |
| [IMX23_LRADC] = { |
| .irq_count = ARRAY_SIZE(mx23_lradc_irq_names), |
| .irq_name = mx23_lradc_irq_names, |
| }, |
| [IMX28_LRADC] = { |
| .irq_count = ARRAY_SIZE(mx28_lradc_irq_names), |
| .irq_name = mx28_lradc_irq_names, |
| }, |
| }; |
| |
| enum mxs_lradc_ts { |
| MXS_LRADC_TOUCHSCREEN_NONE = 0, |
| MXS_LRADC_TOUCHSCREEN_4WIRE, |
| MXS_LRADC_TOUCHSCREEN_5WIRE, |
| }; |
| |
| struct mxs_lradc { |
| struct device *dev; |
| void __iomem *base; |
| int irq[13]; |
| |
| struct clk *clk; |
| |
| uint32_t *buffer; |
| struct iio_trigger *trig; |
| |
| struct mutex lock; |
| |
| struct completion completion; |
| |
| /* |
| * Touchscreen LRADC channels receives a private slot in the CTRL4 |
| * register, the slot #7. Therefore only 7 slots instead of 8 in the |
| * CTRL4 register can be mapped to LRADC channels when using the |
| * touchscreen. |
| * |
| * Furthermore, certain LRADC channels are shared between touchscreen |
| * and/or touch-buttons and generic LRADC block. Therefore when using |
| * either of these, these channels are not available for the regular |
| * sampling. The shared channels are as follows: |
| * |
| * CH0 -- Touch button #0 |
| * CH1 -- Touch button #1 |
| * CH2 -- Touch screen XPUL |
| * CH3 -- Touch screen YPLL |
| * CH4 -- Touch screen XNUL |
| * CH5 -- Touch screen YNLR |
| * CH6 -- Touch screen WIPER (5-wire only) |
| * |
| * The bitfields below represents which parts of the LRADC block are |
| * switched into special mode of operation. These channels can not |
| * be sampled as regular LRADC channels. The driver will refuse any |
| * attempt to sample these channels. |
| */ |
| #define CHAN_MASK_TOUCHBUTTON (0x3 << 0) |
| #define CHAN_MASK_TOUCHSCREEN_4WIRE (0xf << 2) |
| #define CHAN_MASK_TOUCHSCREEN_5WIRE (0x1f << 2) |
| enum mxs_lradc_ts use_touchscreen; |
| bool stop_touchscreen; |
| bool use_touchbutton; |
| |
| struct input_dev *ts_input; |
| struct work_struct ts_work; |
| }; |
| |
| #define LRADC_CTRL0 0x00 |
| #define LRADC_CTRL0_TOUCH_DETECT_ENABLE (1 << 23) |
| #define LRADC_CTRL0_TOUCH_SCREEN_TYPE (1 << 22) |
| #define LRADC_CTRL0_YNNSW /* YM */ (1 << 21) |
| #define LRADC_CTRL0_YPNSW /* YP */ (1 << 20) |
| #define LRADC_CTRL0_YPPSW /* YP */ (1 << 19) |
| #define LRADC_CTRL0_XNNSW /* XM */ (1 << 18) |
| #define LRADC_CTRL0_XNPSW /* XM */ (1 << 17) |
| #define LRADC_CTRL0_XPPSW /* XP */ (1 << 16) |
| #define LRADC_CTRL0_PLATE_MASK (0x3f << 16) |
| |
| #define LRADC_CTRL1 0x10 |
| #define LRADC_CTRL1_TOUCH_DETECT_IRQ_EN (1 << 24) |
| #define LRADC_CTRL1_LRADC_IRQ_EN(n) (1 << ((n) + 16)) |
| #define LRADC_CTRL1_LRADC_IRQ_EN_MASK (0x1fff << 16) |
| #define LRADC_CTRL1_LRADC_IRQ_EN_OFFSET 16 |
| #define LRADC_CTRL1_TOUCH_DETECT_IRQ (1 << 8) |
| #define LRADC_CTRL1_LRADC_IRQ(n) (1 << (n)) |
| #define LRADC_CTRL1_LRADC_IRQ_MASK 0x1fff |
| #define LRADC_CTRL1_LRADC_IRQ_OFFSET 0 |
| |
| #define LRADC_CTRL2 0x20 |
| #define LRADC_CTRL2_TEMPSENSE_PWD (1 << 15) |
| |
| #define LRADC_STATUS 0x40 |
| #define LRADC_STATUS_TOUCH_DETECT_RAW (1 << 0) |
| |
| #define LRADC_CH(n) (0x50 + (0x10 * (n))) |
| #define LRADC_CH_ACCUMULATE (1 << 29) |
| #define LRADC_CH_NUM_SAMPLES_MASK (0x1f << 24) |
| #define LRADC_CH_NUM_SAMPLES_OFFSET 24 |
| #define LRADC_CH_VALUE_MASK 0x3ffff |
| #define LRADC_CH_VALUE_OFFSET 0 |
| |
| #define LRADC_DELAY(n) (0xd0 + (0x10 * (n))) |
| #define LRADC_DELAY_TRIGGER_LRADCS_MASK (0xff << 24) |
| #define LRADC_DELAY_TRIGGER_LRADCS_OFFSET 24 |
| #define LRADC_DELAY_KICK (1 << 20) |
| #define LRADC_DELAY_TRIGGER_DELAYS_MASK (0xf << 16) |
| #define LRADC_DELAY_TRIGGER_DELAYS_OFFSET 16 |
| #define LRADC_DELAY_LOOP_COUNT_MASK (0x1f << 11) |
| #define LRADC_DELAY_LOOP_COUNT_OFFSET 11 |
| #define LRADC_DELAY_DELAY_MASK 0x7ff |
| #define LRADC_DELAY_DELAY_OFFSET 0 |
| |
| #define LRADC_CTRL4 0x140 |
| #define LRADC_CTRL4_LRADCSELECT_MASK(n) (0xf << ((n) * 4)) |
| #define LRADC_CTRL4_LRADCSELECT_OFFSET(n) ((n) * 4) |
| |
| #define LRADC_RESOLUTION 12 |
| #define LRADC_SINGLE_SAMPLE_MASK ((1 << LRADC_RESOLUTION) - 1) |
| |
| /* |
| * Raw I/O operations |
| */ |
| static int mxs_lradc_read_raw(struct iio_dev *iio_dev, |
| const struct iio_chan_spec *chan, |
| int *val, int *val2, long m) |
| { |
| struct mxs_lradc *lradc = iio_priv(iio_dev); |
| int ret; |
| |
| if (m != IIO_CHAN_INFO_RAW) |
| return -EINVAL; |
| |
| /* Check for invalid channel */ |
| if (chan->channel > LRADC_MAX_TOTAL_CHANS) |
| return -EINVAL; |
| |
| /* |
| * See if there is no buffered operation in progess. If there is, simply |
| * bail out. This can be improved to support both buffered and raw IO at |
| * the same time, yet the code becomes horribly complicated. Therefore I |
| * applied KISS principle here. |
| */ |
| ret = mutex_trylock(&lradc->lock); |
| if (!ret) |
| return -EBUSY; |
| |
| INIT_COMPLETION(lradc->completion); |
| |
| /* |
| * No buffered operation in progress, map the channel and trigger it. |
| * Virtual channel 0 is always used here as the others are always not |
| * used if doing raw sampling. |
| */ |
| writel(LRADC_CTRL1_LRADC_IRQ_EN_MASK, |
| lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); |
| writel(0xff, lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR); |
| |
| /* Clean the slot's previous content, then set new one. */ |
| writel(LRADC_CTRL4_LRADCSELECT_MASK(0), |
| lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_CLR); |
| writel(chan->channel, lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET); |
| |
| writel(0, lradc->base + LRADC_CH(0)); |
| |
| /* Enable the IRQ and start sampling the channel. */ |
| writel(LRADC_CTRL1_LRADC_IRQ_EN(0), |
| lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET); |
| writel(1 << 0, lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET); |
| |
| /* Wait for completion on the channel, 1 second max. */ |
| ret = wait_for_completion_killable_timeout(&lradc->completion, HZ); |
| if (!ret) |
| ret = -ETIMEDOUT; |
| if (ret < 0) |
| goto err; |
| |
| /* Read the data. */ |
| *val = readl(lradc->base + LRADC_CH(0)) & LRADC_CH_VALUE_MASK; |
| ret = IIO_VAL_INT; |
| |
| err: |
| writel(LRADC_CTRL1_LRADC_IRQ_EN(0), |
| lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); |
| |
| mutex_unlock(&lradc->lock); |
| |
| return ret; |
| } |
| |
| static const struct iio_info mxs_lradc_iio_info = { |
| .driver_module = THIS_MODULE, |
| .read_raw = mxs_lradc_read_raw, |
| }; |
| |
| /* |
| * Touchscreen handling |
| */ |
| enum lradc_ts_plate { |
| LRADC_SAMPLE_X, |
| LRADC_SAMPLE_Y, |
| LRADC_SAMPLE_PRESSURE, |
| }; |
| |
| static int mxs_lradc_ts_touched(struct mxs_lradc *lradc) |
| { |
| uint32_t reg; |
| |
| /* Enable touch detection. */ |
| writel(LRADC_CTRL0_PLATE_MASK, |
| lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR); |
| writel(LRADC_CTRL0_TOUCH_DETECT_ENABLE, |
| lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET); |
| |
| msleep(LRADC_TS_SAMPLE_DELAY_MS); |
| |
| reg = readl(lradc->base + LRADC_STATUS); |
| |
| return reg & LRADC_STATUS_TOUCH_DETECT_RAW; |
| } |
| |
| static int32_t mxs_lradc_ts_sample(struct mxs_lradc *lradc, |
| enum lradc_ts_plate plate, int change) |
| { |
| unsigned long delay, jiff; |
| uint32_t reg, ctrl0 = 0, chan = 0; |
| /* The touchscreen always uses CTRL4 slot #7. */ |
| const uint8_t slot = 7; |
| uint32_t val; |
| |
| /* |
| * There are three correct configurations of the controller sampling |
| * the touchscreen, each of these configuration provides different |
| * information from the touchscreen. |
| * |
| * The following table describes the sampling configurations: |
| * +-------------+-------+-------+-------+ |
| * | Wire \ Axis | X | Y | Z | |
| * +---------------------+-------+-------+ |
| * | X+ (CH2) | HI | TS | TS | |
| * +-------------+-------+-------+-------+ |
| * | X- (CH4) | LO | SH | HI | |
| * +-------------+-------+-------+-------+ |
| * | Y+ (CH3) | SH | HI | HI | |
| * +-------------+-------+-------+-------+ |
| * | Y- (CH5) | TS | LO | SH | |
| * +-------------+-------+-------+-------+ |
| * |
| * HI ... strong '1' ; LO ... strong '0' |
| * SH ... sample here ; TS ... tri-state |
| * |
| * There are a few other ways of obtaining the Z coordinate |
| * (aka. pressure), but the one in the table seems to be the |
| * most reliable one. |
| */ |
| switch (plate) { |
| case LRADC_SAMPLE_X: |
| ctrl0 = LRADC_CTRL0_XPPSW | LRADC_CTRL0_XNNSW; |
| chan = 3; |
| break; |
| case LRADC_SAMPLE_Y: |
| ctrl0 = LRADC_CTRL0_YPPSW | LRADC_CTRL0_YNNSW; |
| chan = 4; |
| break; |
| case LRADC_SAMPLE_PRESSURE: |
| ctrl0 = LRADC_CTRL0_YPPSW | LRADC_CTRL0_XNNSW; |
| chan = 5; |
| break; |
| } |
| |
| if (change) { |
| writel(LRADC_CTRL0_PLATE_MASK, |
| lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR); |
| writel(ctrl0, lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET); |
| |
| writel(LRADC_CTRL4_LRADCSELECT_MASK(slot), |
| lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_CLR); |
| writel(chan << LRADC_CTRL4_LRADCSELECT_OFFSET(slot), |
| lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET); |
| } |
| |
| writel(0xffffffff, lradc->base + LRADC_CH(slot) + STMP_OFFSET_REG_CLR); |
| writel(1 << slot, lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET); |
| |
| delay = jiffies + msecs_to_jiffies(LRADC_TS_SAMPLE_DELAY_MS); |
| do { |
| jiff = jiffies; |
| reg = readl_relaxed(lradc->base + LRADC_CTRL1); |
| if (reg & LRADC_CTRL1_LRADC_IRQ(slot)) |
| break; |
| } while (time_before(jiff, delay)); |
| |
| writel(LRADC_CTRL1_LRADC_IRQ(slot), |
| lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); |
| |
| if (time_after_eq(jiff, delay)) |
| return -ETIMEDOUT; |
| |
| val = readl(lradc->base + LRADC_CH(slot)); |
| val &= LRADC_CH_VALUE_MASK; |
| |
| return val; |
| } |
| |
| static int32_t mxs_lradc_ts_sample_filter(struct mxs_lradc *lradc, |
| enum lradc_ts_plate plate) |
| { |
| int32_t val, tot = 0; |
| int i; |
| |
| val = mxs_lradc_ts_sample(lradc, plate, 1); |
| |
| /* Delay a bit so the touchscreen is stable. */ |
| mdelay(2); |
| |
| for (i = 0; i < LRADC_TS_SAMPLE_AMOUNT; i++) { |
| val = mxs_lradc_ts_sample(lradc, plate, 0); |
| tot += val; |
| } |
| |
| return tot / LRADC_TS_SAMPLE_AMOUNT; |
| } |
| |
| static void mxs_lradc_ts_work(struct work_struct *ts_work) |
| { |
| struct mxs_lradc *lradc = container_of(ts_work, |
| struct mxs_lradc, ts_work); |
| int val_x, val_y, val_p; |
| bool valid = false; |
| |
| while (mxs_lradc_ts_touched(lradc)) { |
| /* Disable touch detector so we can sample the touchscreen. */ |
| writel(LRADC_CTRL0_TOUCH_DETECT_ENABLE, |
| lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR); |
| |
| if (likely(valid)) { |
| input_report_abs(lradc->ts_input, ABS_X, val_x); |
| input_report_abs(lradc->ts_input, ABS_Y, val_y); |
| input_report_abs(lradc->ts_input, ABS_PRESSURE, val_p); |
| input_report_key(lradc->ts_input, BTN_TOUCH, 1); |
| input_sync(lradc->ts_input); |
| } |
| |
| valid = false; |
| |
| val_x = mxs_lradc_ts_sample_filter(lradc, LRADC_SAMPLE_X); |
| if (val_x < 0) |
| continue; |
| val_y = mxs_lradc_ts_sample_filter(lradc, LRADC_SAMPLE_Y); |
| if (val_y < 0) |
| continue; |
| val_p = mxs_lradc_ts_sample_filter(lradc, LRADC_SAMPLE_PRESSURE); |
| if (val_p < 0) |
| continue; |
| |
| valid = true; |
| } |
| |
| input_report_abs(lradc->ts_input, ABS_PRESSURE, 0); |
| input_report_key(lradc->ts_input, BTN_TOUCH, 0); |
| input_sync(lradc->ts_input); |
| |
| /* Do not restart the TS IRQ if the driver is shutting down. */ |
| if (lradc->stop_touchscreen) |
| return; |
| |
| /* Restart the touchscreen interrupts. */ |
| writel(LRADC_CTRL1_TOUCH_DETECT_IRQ, |
| lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); |
| writel(LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, |
| lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET); |
| } |
| |
| static int mxs_lradc_ts_open(struct input_dev *dev) |
| { |
| struct mxs_lradc *lradc = input_get_drvdata(dev); |
| |
| /* The touchscreen is starting. */ |
| lradc->stop_touchscreen = false; |
| |
| /* Enable the touch-detect circuitry. */ |
| writel(LRADC_CTRL0_TOUCH_DETECT_ENABLE, |
| lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET); |
| |
| /* Enable the touch-detect IRQ. */ |
| writel(LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, |
| lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET); |
| |
| return 0; |
| } |
| |
| static void mxs_lradc_ts_close(struct input_dev *dev) |
| { |
| struct mxs_lradc *lradc = input_get_drvdata(dev); |
| |
| /* Indicate the touchscreen is stopping. */ |
| lradc->stop_touchscreen = true; |
| mb(); |
| |
| /* Wait until touchscreen thread finishes any possible remnants. */ |
| cancel_work_sync(&lradc->ts_work); |
| |
| /* Disable touchscreen touch-detect IRQ. */ |
| writel(LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, |
| lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); |
| |
| /* Power-down touchscreen touch-detect circuitry. */ |
| writel(LRADC_CTRL0_TOUCH_DETECT_ENABLE, |
| lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR); |
| } |
| |
| static int mxs_lradc_ts_register(struct mxs_lradc *lradc) |
| { |
| struct input_dev *input; |
| struct device *dev = lradc->dev; |
| int ret; |
| |
| if (!lradc->use_touchscreen) |
| return 0; |
| |
| input = input_allocate_device(); |
| if (!input) { |
| dev_err(dev, "Failed to allocate TS device!\n"); |
| return -ENOMEM; |
| } |
| |
| input->name = DRIVER_NAME; |
| input->id.bustype = BUS_HOST; |
| input->dev.parent = dev; |
| input->open = mxs_lradc_ts_open; |
| input->close = mxs_lradc_ts_close; |
| |
| __set_bit(EV_ABS, input->evbit); |
| __set_bit(EV_KEY, input->evbit); |
| __set_bit(BTN_TOUCH, input->keybit); |
| input_set_abs_params(input, ABS_X, 0, LRADC_SINGLE_SAMPLE_MASK, 0, 0); |
| input_set_abs_params(input, ABS_Y, 0, LRADC_SINGLE_SAMPLE_MASK, 0, 0); |
| input_set_abs_params(input, ABS_PRESSURE, 0, LRADC_SINGLE_SAMPLE_MASK, |
| 0, 0); |
| |
| lradc->ts_input = input; |
| input_set_drvdata(input, lradc); |
| ret = input_register_device(input); |
| if (ret) |
| input_free_device(lradc->ts_input); |
| |
| return ret; |
| } |
| |
| static void mxs_lradc_ts_unregister(struct mxs_lradc *lradc) |
| { |
| if (!lradc->use_touchscreen) |
| return; |
| |
| cancel_work_sync(&lradc->ts_work); |
| |
| input_unregister_device(lradc->ts_input); |
| } |
| |
| /* |
| * IRQ Handling |
| */ |
| static irqreturn_t mxs_lradc_handle_irq(int irq, void *data) |
| { |
| struct iio_dev *iio = data; |
| struct mxs_lradc *lradc = iio_priv(iio); |
| unsigned long reg = readl(lradc->base + LRADC_CTRL1); |
| const uint32_t ts_irq_mask = |
| LRADC_CTRL1_TOUCH_DETECT_IRQ_EN | |
| LRADC_CTRL1_TOUCH_DETECT_IRQ; |
| |
| if (!(reg & LRADC_CTRL1_LRADC_IRQ_MASK)) |
| return IRQ_NONE; |
| |
| /* |
| * Touchscreen IRQ handling code has priority and therefore |
| * is placed here. In case touchscreen IRQ arrives, disable |
| * it ASAP |
| */ |
| if (reg & LRADC_CTRL1_TOUCH_DETECT_IRQ) { |
| writel(ts_irq_mask, |
| lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); |
| if (!lradc->stop_touchscreen) |
| schedule_work(&lradc->ts_work); |
| } |
| |
| if (iio_buffer_enabled(iio)) |
| iio_trigger_poll(iio->trig, iio_get_time_ns()); |
| else if (reg & LRADC_CTRL1_LRADC_IRQ(0)) |
| complete(&lradc->completion); |
| |
| writel(reg & LRADC_CTRL1_LRADC_IRQ_MASK, |
| lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); |
| |
| return IRQ_HANDLED; |
| } |
| |
| /* |
| * Trigger handling |
| */ |
| static irqreturn_t mxs_lradc_trigger_handler(int irq, void *p) |
| { |
| struct iio_poll_func *pf = p; |
| struct iio_dev *iio = pf->indio_dev; |
| struct mxs_lradc *lradc = iio_priv(iio); |
| const uint32_t chan_value = LRADC_CH_ACCUMULATE | |
| ((LRADC_DELAY_TIMER_LOOP - 1) << LRADC_CH_NUM_SAMPLES_OFFSET); |
| unsigned int i, j = 0; |
| |
| for_each_set_bit(i, iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS) { |
| lradc->buffer[j] = readl(lradc->base + LRADC_CH(j)); |
| writel(chan_value, lradc->base + LRADC_CH(j)); |
| lradc->buffer[j] &= LRADC_CH_VALUE_MASK; |
| lradc->buffer[j] /= LRADC_DELAY_TIMER_LOOP; |
| j++; |
| } |
| |
| iio_push_to_buffers_with_timestamp(iio, lradc->buffer, pf->timestamp); |
| |
| iio_trigger_notify_done(iio->trig); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static int mxs_lradc_configure_trigger(struct iio_trigger *trig, bool state) |
| { |
| struct iio_dev *iio = iio_trigger_get_drvdata(trig); |
| struct mxs_lradc *lradc = iio_priv(iio); |
| const uint32_t st = state ? STMP_OFFSET_REG_SET : STMP_OFFSET_REG_CLR; |
| |
| writel(LRADC_DELAY_KICK, lradc->base + LRADC_DELAY(0) + st); |
| |
| return 0; |
| } |
| |
| static const struct iio_trigger_ops mxs_lradc_trigger_ops = { |
| .owner = THIS_MODULE, |
| .set_trigger_state = &mxs_lradc_configure_trigger, |
| }; |
| |
| static int mxs_lradc_trigger_init(struct iio_dev *iio) |
| { |
| int ret; |
| struct iio_trigger *trig; |
| struct mxs_lradc *lradc = iio_priv(iio); |
| |
| trig = iio_trigger_alloc("%s-dev%i", iio->name, iio->id); |
| if (trig == NULL) |
| return -ENOMEM; |
| |
| trig->dev.parent = lradc->dev; |
| iio_trigger_set_drvdata(trig, iio); |
| trig->ops = &mxs_lradc_trigger_ops; |
| |
| ret = iio_trigger_register(trig); |
| if (ret) { |
| iio_trigger_free(trig); |
| return ret; |
| } |
| |
| lradc->trig = trig; |
| |
| return 0; |
| } |
| |
| static void mxs_lradc_trigger_remove(struct iio_dev *iio) |
| { |
| struct mxs_lradc *lradc = iio_priv(iio); |
| |
| iio_trigger_unregister(lradc->trig); |
| iio_trigger_free(lradc->trig); |
| } |
| |
| static int mxs_lradc_buffer_preenable(struct iio_dev *iio) |
| { |
| struct mxs_lradc *lradc = iio_priv(iio); |
| int ret = 0, chan, ofs = 0; |
| unsigned long enable = 0; |
| uint32_t ctrl4_set = 0; |
| uint32_t ctrl4_clr = 0; |
| uint32_t ctrl1_irq = 0; |
| const uint32_t chan_value = LRADC_CH_ACCUMULATE | |
| ((LRADC_DELAY_TIMER_LOOP - 1) << LRADC_CH_NUM_SAMPLES_OFFSET); |
| const int len = bitmap_weight(iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS); |
| |
| if (!len) |
| return -EINVAL; |
| |
| /* |
| * Lock the driver so raw access can not be done during buffered |
| * operation. This simplifies the code a lot. |
| */ |
| ret = mutex_trylock(&lradc->lock); |
| if (!ret) |
| return -EBUSY; |
| |
| lradc->buffer = kmalloc(len * sizeof(*lradc->buffer), GFP_KERNEL); |
| if (!lradc->buffer) { |
| ret = -ENOMEM; |
| goto err_mem; |
| } |
| |
| ret = iio_sw_buffer_preenable(iio); |
| if (ret < 0) |
| goto err_buf; |
| |
| writel(LRADC_CTRL1_LRADC_IRQ_EN_MASK, |
| lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); |
| writel(0xff, lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR); |
| |
| for_each_set_bit(chan, iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS) { |
| ctrl4_set |= chan << LRADC_CTRL4_LRADCSELECT_OFFSET(ofs); |
| ctrl4_clr |= LRADC_CTRL4_LRADCSELECT_MASK(ofs); |
| ctrl1_irq |= LRADC_CTRL1_LRADC_IRQ_EN(ofs); |
| writel(chan_value, lradc->base + LRADC_CH(ofs)); |
| bitmap_set(&enable, ofs, 1); |
| ofs++; |
| } |
| |
| writel(LRADC_DELAY_TRIGGER_LRADCS_MASK | LRADC_DELAY_KICK, |
| lradc->base + LRADC_DELAY(0) + STMP_OFFSET_REG_CLR); |
| |
| writel(ctrl4_clr, lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_CLR); |
| writel(ctrl4_set, lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET); |
| |
| writel(ctrl1_irq, lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET); |
| |
| writel(enable << LRADC_DELAY_TRIGGER_LRADCS_OFFSET, |
| lradc->base + LRADC_DELAY(0) + STMP_OFFSET_REG_SET); |
| |
| return 0; |
| |
| err_buf: |
| kfree(lradc->buffer); |
| err_mem: |
| mutex_unlock(&lradc->lock); |
| return ret; |
| } |
| |
| static int mxs_lradc_buffer_postdisable(struct iio_dev *iio) |
| { |
| struct mxs_lradc *lradc = iio_priv(iio); |
| |
| writel(LRADC_DELAY_TRIGGER_LRADCS_MASK | LRADC_DELAY_KICK, |
| lradc->base + LRADC_DELAY(0) + STMP_OFFSET_REG_CLR); |
| |
| writel(0xff, lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR); |
| writel(LRADC_CTRL1_LRADC_IRQ_EN_MASK, |
| lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); |
| |
| kfree(lradc->buffer); |
| mutex_unlock(&lradc->lock); |
| |
| return 0; |
| } |
| |
| static bool mxs_lradc_validate_scan_mask(struct iio_dev *iio, |
| const unsigned long *mask) |
| { |
| struct mxs_lradc *lradc = iio_priv(iio); |
| const int map_chans = bitmap_weight(mask, LRADC_MAX_TOTAL_CHANS); |
| int rsvd_chans = 0; |
| unsigned long rsvd_mask = 0; |
| |
| if (lradc->use_touchbutton) |
| rsvd_mask |= CHAN_MASK_TOUCHBUTTON; |
| if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_4WIRE) |
| rsvd_mask |= CHAN_MASK_TOUCHSCREEN_4WIRE; |
| if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_5WIRE) |
| rsvd_mask |= CHAN_MASK_TOUCHSCREEN_5WIRE; |
| |
| if (lradc->use_touchbutton) |
| rsvd_chans++; |
| if (lradc->use_touchscreen) |
| rsvd_chans++; |
| |
| /* Test for attempts to map channels with special mode of operation. */ |
| if (bitmap_intersects(mask, &rsvd_mask, LRADC_MAX_TOTAL_CHANS)) |
| return false; |
| |
| /* Test for attempts to map more channels then available slots. */ |
| if (map_chans + rsvd_chans > LRADC_MAX_MAPPED_CHANS) |
| return false; |
| |
| return true; |
| } |
| |
| static const struct iio_buffer_setup_ops mxs_lradc_buffer_ops = { |
| .preenable = &mxs_lradc_buffer_preenable, |
| .postenable = &iio_triggered_buffer_postenable, |
| .predisable = &iio_triggered_buffer_predisable, |
| .postdisable = &mxs_lradc_buffer_postdisable, |
| .validate_scan_mask = &mxs_lradc_validate_scan_mask, |
| }; |
| |
| /* |
| * Driver initialization |
| */ |
| |
| #define MXS_ADC_CHAN(idx, chan_type) { \ |
| .type = (chan_type), \ |
| .indexed = 1, \ |
| .scan_index = (idx), \ |
| .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ |
| .channel = (idx), \ |
| .scan_type = { \ |
| .sign = 'u', \ |
| .realbits = LRADC_RESOLUTION, \ |
| .storagebits = 32, \ |
| }, \ |
| } |
| |
| static const struct iio_chan_spec mxs_lradc_chan_spec[] = { |
| MXS_ADC_CHAN(0, IIO_VOLTAGE), |
| MXS_ADC_CHAN(1, IIO_VOLTAGE), |
| MXS_ADC_CHAN(2, IIO_VOLTAGE), |
| MXS_ADC_CHAN(3, IIO_VOLTAGE), |
| MXS_ADC_CHAN(4, IIO_VOLTAGE), |
| MXS_ADC_CHAN(5, IIO_VOLTAGE), |
| MXS_ADC_CHAN(6, IIO_VOLTAGE), |
| MXS_ADC_CHAN(7, IIO_VOLTAGE), /* VBATT */ |
| MXS_ADC_CHAN(8, IIO_TEMP), /* Temp sense 0 */ |
| MXS_ADC_CHAN(9, IIO_TEMP), /* Temp sense 1 */ |
| MXS_ADC_CHAN(10, IIO_VOLTAGE), /* VDDIO */ |
| MXS_ADC_CHAN(11, IIO_VOLTAGE), /* VTH */ |
| MXS_ADC_CHAN(12, IIO_VOLTAGE), /* VDDA */ |
| MXS_ADC_CHAN(13, IIO_VOLTAGE), /* VDDD */ |
| MXS_ADC_CHAN(14, IIO_VOLTAGE), /* VBG */ |
| MXS_ADC_CHAN(15, IIO_VOLTAGE), /* VDD5V */ |
| }; |
| |
| static int mxs_lradc_hw_init(struct mxs_lradc *lradc) |
| { |
| /* The ADC always uses DELAY CHANNEL 0. */ |
| const uint32_t adc_cfg = |
| (1 << (LRADC_DELAY_TRIGGER_DELAYS_OFFSET + 0)) | |
| (LRADC_DELAY_TIMER_PER << LRADC_DELAY_DELAY_OFFSET); |
| |
| int ret = stmp_reset_block(lradc->base); |
| if (ret) |
| return ret; |
| |
| /* Configure DELAY CHANNEL 0 for generic ADC sampling. */ |
| writel(adc_cfg, lradc->base + LRADC_DELAY(0)); |
| |
| /* Disable remaining DELAY CHANNELs */ |
| writel(0, lradc->base + LRADC_DELAY(1)); |
| writel(0, lradc->base + LRADC_DELAY(2)); |
| writel(0, lradc->base + LRADC_DELAY(3)); |
| |
| /* Configure the touchscreen type */ |
| writel(LRADC_CTRL0_TOUCH_SCREEN_TYPE, |
| lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR); |
| |
| if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_5WIRE) { |
| writel(LRADC_CTRL0_TOUCH_SCREEN_TYPE, |
| lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET); |
| } |
| |
| /* Start internal temperature sensing. */ |
| writel(0, lradc->base + LRADC_CTRL2); |
| |
| return 0; |
| } |
| |
| static void mxs_lradc_hw_stop(struct mxs_lradc *lradc) |
| { |
| int i; |
| |
| writel(LRADC_CTRL1_LRADC_IRQ_EN_MASK, |
| lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); |
| |
| for (i = 0; i < LRADC_MAX_DELAY_CHANS; i++) |
| writel(0, lradc->base + LRADC_DELAY(i)); |
| } |
| |
| static const struct of_device_id mxs_lradc_dt_ids[] = { |
| { .compatible = "fsl,imx23-lradc", .data = (void *)IMX23_LRADC, }, |
| { .compatible = "fsl,imx28-lradc", .data = (void *)IMX28_LRADC, }, |
| { /* sentinel */ } |
| }; |
| MODULE_DEVICE_TABLE(of, mxs_lradc_dt_ids); |
| |
| static int mxs_lradc_probe(struct platform_device *pdev) |
| { |
| const struct of_device_id *of_id = |
| of_match_device(mxs_lradc_dt_ids, &pdev->dev); |
| const struct mxs_lradc_of_config *of_cfg = |
| &mxs_lradc_of_config[(enum mxs_lradc_id)of_id->data]; |
| struct device *dev = &pdev->dev; |
| struct device_node *node = dev->of_node; |
| struct mxs_lradc *lradc; |
| struct iio_dev *iio; |
| struct resource *iores; |
| uint32_t ts_wires = 0; |
| int ret = 0; |
| int i; |
| |
| /* Allocate the IIO device. */ |
| iio = devm_iio_device_alloc(dev, sizeof(*lradc)); |
| if (!iio) { |
| dev_err(dev, "Failed to allocate IIO device\n"); |
| return -ENOMEM; |
| } |
| |
| lradc = iio_priv(iio); |
| |
| /* Grab the memory area */ |
| iores = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| lradc->dev = &pdev->dev; |
| lradc->base = devm_ioremap_resource(dev, iores); |
| if (IS_ERR(lradc->base)) |
| return PTR_ERR(lradc->base); |
| |
| lradc->clk = devm_clk_get(&pdev->dev, NULL); |
| if (IS_ERR(lradc->clk)) { |
| dev_err(dev, "Failed to get the delay unit clock\n"); |
| return PTR_ERR(lradc->clk); |
| } |
| ret = clk_prepare_enable(lradc->clk); |
| if (ret != 0) { |
| dev_err(dev, "Failed to enable the delay unit clock\n"); |
| return ret; |
| } |
| |
| INIT_WORK(&lradc->ts_work, mxs_lradc_ts_work); |
| |
| /* Check if touchscreen is enabled in DT. */ |
| ret = of_property_read_u32(node, "fsl,lradc-touchscreen-wires", |
| &ts_wires); |
| if (ret) |
| dev_info(dev, "Touchscreen not enabled.\n"); |
| else if (ts_wires == 4) |
| lradc->use_touchscreen = MXS_LRADC_TOUCHSCREEN_4WIRE; |
| else if (ts_wires == 5) |
| lradc->use_touchscreen = MXS_LRADC_TOUCHSCREEN_5WIRE; |
| else |
| dev_warn(dev, "Unsupported number of touchscreen wires (%d)\n", |
| ts_wires); |
| |
| /* Grab all IRQ sources */ |
| for (i = 0; i < of_cfg->irq_count; i++) { |
| lradc->irq[i] = platform_get_irq(pdev, i); |
| if (lradc->irq[i] < 0) |
| return -EINVAL; |
| |
| ret = devm_request_irq(dev, lradc->irq[i], |
| mxs_lradc_handle_irq, 0, |
| of_cfg->irq_name[i], iio); |
| if (ret) |
| return ret; |
| } |
| |
| platform_set_drvdata(pdev, iio); |
| |
| init_completion(&lradc->completion); |
| mutex_init(&lradc->lock); |
| |
| iio->name = pdev->name; |
| iio->dev.parent = &pdev->dev; |
| iio->info = &mxs_lradc_iio_info; |
| iio->modes = INDIO_DIRECT_MODE; |
| iio->channels = mxs_lradc_chan_spec; |
| iio->num_channels = ARRAY_SIZE(mxs_lradc_chan_spec); |
| iio->masklength = LRADC_MAX_TOTAL_CHANS; |
| |
| ret = iio_triggered_buffer_setup(iio, &iio_pollfunc_store_time, |
| &mxs_lradc_trigger_handler, |
| &mxs_lradc_buffer_ops); |
| if (ret) |
| return ret; |
| |
| ret = mxs_lradc_trigger_init(iio); |
| if (ret) |
| goto err_trig; |
| |
| /* Configure the hardware. */ |
| ret = mxs_lradc_hw_init(lradc); |
| if (ret) |
| goto err_dev; |
| |
| /* Register the touchscreen input device. */ |
| ret = mxs_lradc_ts_register(lradc); |
| if (ret) |
| goto err_ts_register; |
| |
| /* Register IIO device. */ |
| ret = iio_device_register(iio); |
| if (ret) { |
| dev_err(dev, "Failed to register IIO device\n"); |
| goto err_ts; |
| } |
| |
| return 0; |
| |
| err_ts: |
| mxs_lradc_ts_unregister(lradc); |
| err_ts_register: |
| mxs_lradc_hw_stop(lradc); |
| err_dev: |
| mxs_lradc_trigger_remove(iio); |
| err_trig: |
| iio_triggered_buffer_cleanup(iio); |
| return ret; |
| } |
| |
| static int mxs_lradc_remove(struct platform_device *pdev) |
| { |
| struct iio_dev *iio = platform_get_drvdata(pdev); |
| struct mxs_lradc *lradc = iio_priv(iio); |
| |
| iio_device_unregister(iio); |
| mxs_lradc_ts_unregister(lradc); |
| mxs_lradc_hw_stop(lradc); |
| mxs_lradc_trigger_remove(iio); |
| iio_triggered_buffer_cleanup(iio); |
| |
| clk_disable_unprepare(lradc->clk); |
| return 0; |
| } |
| |
| static struct platform_driver mxs_lradc_driver = { |
| .driver = { |
| .name = DRIVER_NAME, |
| .owner = THIS_MODULE, |
| .of_match_table = mxs_lradc_dt_ids, |
| }, |
| .probe = mxs_lradc_probe, |
| .remove = mxs_lradc_remove, |
| }; |
| |
| module_platform_driver(mxs_lradc_driver); |
| |
| MODULE_AUTHOR("Marek Vasut <marex@denx.de>"); |
| MODULE_DESCRIPTION("Freescale i.MX28 LRADC driver"); |
| MODULE_LICENSE("GPL v2"); |
| MODULE_ALIAS("platform:" DRIVER_NAME); |