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path: root/drivers/iio/adc/mxs-lradc.c
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-rw-r--r--drivers/iio/adc/mxs-lradc.c1775
1 files changed, 1775 insertions, 0 deletions
diff --git a/drivers/iio/adc/mxs-lradc.c b/drivers/iio/adc/mxs-lradc.c
new file mode 100644
index 000000000000..33051b87aac2
--- /dev/null
+++ b/drivers/iio/adc/mxs-lradc.c
@@ -0,0 +1,1775 @@
+/*
+ * Freescale MXS 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/bitops.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/stmp_device.h>
+#include <linux/sysfs.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/sysfs.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 fluency 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 average 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;
+ const u32 *vref_mv;
+};
+
+#define VREF_MV_BASE 1850
+
+static const u32 mx23_vref_mv[LRADC_MAX_TOTAL_CHANS] = {
+ VREF_MV_BASE, /* CH0 */
+ VREF_MV_BASE, /* CH1 */
+ VREF_MV_BASE, /* CH2 */
+ VREF_MV_BASE, /* CH3 */
+ VREF_MV_BASE, /* CH4 */
+ VREF_MV_BASE, /* CH5 */
+ VREF_MV_BASE * 2, /* CH6 VDDIO */
+ VREF_MV_BASE * 4, /* CH7 VBATT */
+ VREF_MV_BASE, /* CH8 Temp sense 0 */
+ VREF_MV_BASE, /* CH9 Temp sense 1 */
+ VREF_MV_BASE, /* CH10 */
+ VREF_MV_BASE, /* CH11 */
+ VREF_MV_BASE, /* CH12 USB_DP */
+ VREF_MV_BASE, /* CH13 USB_DN */
+ VREF_MV_BASE, /* CH14 VBG */
+ VREF_MV_BASE * 4, /* CH15 VDD5V */
+};
+
+static const u32 mx28_vref_mv[LRADC_MAX_TOTAL_CHANS] = {
+ VREF_MV_BASE, /* CH0 */
+ VREF_MV_BASE, /* CH1 */
+ VREF_MV_BASE, /* CH2 */
+ VREF_MV_BASE, /* CH3 */
+ VREF_MV_BASE, /* CH4 */
+ VREF_MV_BASE, /* CH5 */
+ VREF_MV_BASE, /* CH6 */
+ VREF_MV_BASE * 4, /* CH7 VBATT */
+ VREF_MV_BASE, /* CH8 Temp sense 0 */
+ VREF_MV_BASE, /* CH9 Temp sense 1 */
+ VREF_MV_BASE * 2, /* CH10 VDDIO */
+ VREF_MV_BASE, /* CH11 VTH */
+ VREF_MV_BASE * 2, /* CH12 VDDA */
+ VREF_MV_BASE, /* CH13 VDDD */
+ VREF_MV_BASE, /* CH14 VBG */
+ VREF_MV_BASE * 4, /* CH15 VDD5V */
+};
+
+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,
+ .vref_mv = mx23_vref_mv,
+ },
+ [IMX28_LRADC] = {
+ .irq_count = ARRAY_SIZE(mx28_lradc_irq_names),
+ .irq_name = mx28_lradc_irq_names,
+ .vref_mv = mx28_vref_mv,
+ },
+};
+
+enum mxs_lradc_ts {
+ MXS_LRADC_TOUCHSCREEN_NONE = 0,
+ MXS_LRADC_TOUCHSCREEN_4WIRE,
+ MXS_LRADC_TOUCHSCREEN_5WIRE,
+};
+
+/*
+ * Touchscreen handling
+ */
+enum lradc_ts_plate {
+ LRADC_TOUCH = 0,
+ LRADC_SAMPLE_X,
+ LRADC_SAMPLE_Y,
+ LRADC_SAMPLE_PRESSURE,
+ LRADC_SAMPLE_VALID,
+};
+
+enum mxs_lradc_divbytwo {
+ MXS_LRADC_DIV_DISABLED = 0,
+ MXS_LRADC_DIV_ENABLED,
+};
+
+struct mxs_lradc_scale {
+ unsigned int integer;
+ unsigned int nano;
+};
+
+struct mxs_lradc {
+ struct device *dev;
+ void __iomem *base;
+ int irq[13];
+
+ struct clk *clk;
+
+ u32 *buffer;
+ struct iio_trigger *trig;
+
+ struct mutex lock;
+
+ struct completion completion;
+
+ const u32 *vref_mv;
+ struct mxs_lradc_scale scale_avail[LRADC_MAX_TOTAL_CHANS][2];
+ unsigned long is_divided;
+
+ /*
+ * When the touchscreen is enabled, we give it two private virtual
+ * channels: #6 and #7. This means that only 6 virtual channels (instead
+ * of 8) will be available for buffered capture.
+ */
+#define TOUCHSCREEN_VCHANNEL1 7
+#define TOUCHSCREEN_VCHANNEL2 6
+#define BUFFER_VCHANS_LIMITED 0x3f
+#define BUFFER_VCHANS_ALL 0xff
+ u8 buffer_vchans;
+
+ /*
+ * 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 bit fields 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 (BIT(1) | BIT(0))
+#define CHAN_MASK_TOUCHSCREEN_4WIRE (0xf << 2)
+#define CHAN_MASK_TOUCHSCREEN_5WIRE (0x1f << 2)
+ enum mxs_lradc_ts use_touchscreen;
+ bool use_touchbutton;
+
+ struct input_dev *ts_input;
+
+ enum mxs_lradc_id soc;
+ enum lradc_ts_plate cur_plate; /* state machine */
+ bool ts_valid;
+ unsigned ts_x_pos;
+ unsigned ts_y_pos;
+ unsigned ts_pressure;
+
+ /* handle touchscreen's physical behaviour */
+ /* samples per coordinate */
+ unsigned over_sample_cnt;
+ /* time clocks between samples */
+ unsigned over_sample_delay;
+ /* time in clocks to wait after the plates where switched */
+ unsigned settling_delay;
+};
+
+#define LRADC_CTRL0 0x00
+# define LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE BIT(23)
+# define LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE BIT(22)
+# define LRADC_CTRL0_MX28_YNNSW /* YM */ BIT(21)
+# define LRADC_CTRL0_MX28_YPNSW /* YP */ BIT(20)
+# define LRADC_CTRL0_MX28_YPPSW /* YP */ BIT(19)
+# define LRADC_CTRL0_MX28_XNNSW /* XM */ BIT(18)
+# define LRADC_CTRL0_MX28_XNPSW /* XM */ BIT(17)
+# define LRADC_CTRL0_MX28_XPPSW /* XP */ BIT(16)
+
+# define LRADC_CTRL0_MX23_TOUCH_DETECT_ENABLE BIT(20)
+# define LRADC_CTRL0_MX23_YM BIT(19)
+# define LRADC_CTRL0_MX23_XM BIT(18)
+# define LRADC_CTRL0_MX23_YP BIT(17)
+# define LRADC_CTRL0_MX23_XP BIT(16)
+
+# define LRADC_CTRL0_MX28_PLATE_MASK \
+ (LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE | \
+ LRADC_CTRL0_MX28_YNNSW | LRADC_CTRL0_MX28_YPNSW | \
+ LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_XNNSW | \
+ LRADC_CTRL0_MX28_XNPSW | LRADC_CTRL0_MX28_XPPSW)
+
+# define LRADC_CTRL0_MX23_PLATE_MASK \
+ (LRADC_CTRL0_MX23_TOUCH_DETECT_ENABLE | \
+ LRADC_CTRL0_MX23_YM | LRADC_CTRL0_MX23_XM | \
+ LRADC_CTRL0_MX23_YP | LRADC_CTRL0_MX23_XP)
+
+#define LRADC_CTRL1 0x10
+#define LRADC_CTRL1_TOUCH_DETECT_IRQ_EN BIT(24)
+#define LRADC_CTRL1_LRADC_IRQ_EN(n) (1 << ((n) + 16))
+#define LRADC_CTRL1_MX28_LRADC_IRQ_EN_MASK (0x1fff << 16)
+#define LRADC_CTRL1_MX23_LRADC_IRQ_EN_MASK (0x01ff << 16)
+#define LRADC_CTRL1_LRADC_IRQ_EN_OFFSET 16
+#define LRADC_CTRL1_TOUCH_DETECT_IRQ BIT(8)
+#define LRADC_CTRL1_LRADC_IRQ(n) (1 << (n))
+#define LRADC_CTRL1_MX28_LRADC_IRQ_MASK 0x1fff
+#define LRADC_CTRL1_MX23_LRADC_IRQ_MASK 0x01ff
+#define LRADC_CTRL1_LRADC_IRQ_OFFSET 0
+
+#define LRADC_CTRL2 0x20
+#define LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET 24
+#define LRADC_CTRL2_TEMPSENSE_PWD BIT(15)
+
+#define LRADC_STATUS 0x40
+#define LRADC_STATUS_TOUCH_DETECT_RAW BIT(0)
+
+#define LRADC_CH(n) (0x50 + (0x10 * (n)))
+#define LRADC_CH_ACCUMULATE BIT(29)
+#define LRADC_CH_NUM_SAMPLES_MASK (0x1f << 24)
+#define LRADC_CH_NUM_SAMPLES_OFFSET 24
+#define LRADC_CH_NUM_SAMPLES(x) \
+ ((x) << LRADC_CH_NUM_SAMPLES_OFFSET)
+#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 (0xffUL << 24)
+#define LRADC_DELAY_TRIGGER_LRADCS_OFFSET 24
+#define LRADC_DELAY_TRIGGER(x) \
+ (((x) << LRADC_DELAY_TRIGGER_LRADCS_OFFSET) & \
+ LRADC_DELAY_TRIGGER_LRADCS_MASK)
+#define LRADC_DELAY_KICK BIT(20)
+#define LRADC_DELAY_TRIGGER_DELAYS_MASK (0xf << 16)
+#define LRADC_DELAY_TRIGGER_DELAYS_OFFSET 16
+#define LRADC_DELAY_TRIGGER_DELAYS(x) \
+ (((x) << LRADC_DELAY_TRIGGER_DELAYS_OFFSET) & \
+ LRADC_DELAY_TRIGGER_DELAYS_MASK)
+#define LRADC_DELAY_LOOP_COUNT_MASK (0x1f << 11)
+#define LRADC_DELAY_LOOP_COUNT_OFFSET 11
+#define LRADC_DELAY_LOOP(x) \
+ (((x) << LRADC_DELAY_LOOP_COUNT_OFFSET) & \
+ LRADC_DELAY_LOOP_COUNT_MASK)
+#define LRADC_DELAY_DELAY_MASK 0x7ff
+#define LRADC_DELAY_DELAY_OFFSET 0
+#define LRADC_DELAY_DELAY(x) \
+ (((x) << LRADC_DELAY_DELAY_OFFSET) & \
+ LRADC_DELAY_DELAY_MASK)
+
+#define LRADC_CTRL4 0x140
+#define LRADC_CTRL4_LRADCSELECT_MASK(n) (0xf << ((n) * 4))
+#define LRADC_CTRL4_LRADCSELECT_OFFSET(n) ((n) * 4)
+#define LRADC_CTRL4_LRADCSELECT(n, x) \
+ (((x) << LRADC_CTRL4_LRADCSELECT_OFFSET(n)) & \
+ LRADC_CTRL4_LRADCSELECT_MASK(n))
+
+#define LRADC_RESOLUTION 12
+#define LRADC_SINGLE_SAMPLE_MASK ((1 << LRADC_RESOLUTION) - 1)
+
+static void mxs_lradc_reg_set(struct mxs_lradc *lradc, u32 val, u32 reg)
+{
+ writel(val, lradc->base + reg + STMP_OFFSET_REG_SET);
+}
+
+static void mxs_lradc_reg_clear(struct mxs_lradc *lradc, u32 val, u32 reg)
+{
+ writel(val, lradc->base + reg + STMP_OFFSET_REG_CLR);
+}
+
+static void mxs_lradc_reg_wrt(struct mxs_lradc *lradc, u32 val, u32 reg)
+{
+ writel(val, lradc->base + reg);
+}
+
+static u32 mxs_lradc_plate_mask(struct mxs_lradc *lradc)
+{
+ if (lradc->soc == IMX23_LRADC)
+ return LRADC_CTRL0_MX23_PLATE_MASK;
+ return LRADC_CTRL0_MX28_PLATE_MASK;
+}
+
+static u32 mxs_lradc_irq_en_mask(struct mxs_lradc *lradc)
+{
+ if (lradc->soc == IMX23_LRADC)
+ return LRADC_CTRL1_MX23_LRADC_IRQ_EN_MASK;
+ return LRADC_CTRL1_MX28_LRADC_IRQ_EN_MASK;
+}
+
+static u32 mxs_lradc_irq_mask(struct mxs_lradc *lradc)
+{
+ if (lradc->soc == IMX23_LRADC)
+ return LRADC_CTRL1_MX23_LRADC_IRQ_MASK;
+ return LRADC_CTRL1_MX28_LRADC_IRQ_MASK;
+}
+
+static u32 mxs_lradc_touch_detect_bit(struct mxs_lradc *lradc)
+{
+ if (lradc->soc == IMX23_LRADC)
+ return LRADC_CTRL0_MX23_TOUCH_DETECT_ENABLE;
+ return LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE;
+}
+
+static u32 mxs_lradc_drive_x_plate(struct mxs_lradc *lradc)
+{
+ if (lradc->soc == IMX23_LRADC)
+ return LRADC_CTRL0_MX23_XP | LRADC_CTRL0_MX23_XM;
+ return LRADC_CTRL0_MX28_XPPSW | LRADC_CTRL0_MX28_XNNSW;
+}
+
+static u32 mxs_lradc_drive_y_plate(struct mxs_lradc *lradc)
+{
+ if (lradc->soc == IMX23_LRADC)
+ return LRADC_CTRL0_MX23_YP | LRADC_CTRL0_MX23_YM;
+ return LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_YNNSW;
+}
+
+static u32 mxs_lradc_drive_pressure(struct mxs_lradc *lradc)
+{
+ if (lradc->soc == IMX23_LRADC)
+ return LRADC_CTRL0_MX23_YP | LRADC_CTRL0_MX23_XM;
+ return LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_XNNSW;
+}
+
+static bool mxs_lradc_check_touch_event(struct mxs_lradc *lradc)
+{
+ return !!(readl(lradc->base + LRADC_STATUS) &
+ LRADC_STATUS_TOUCH_DETECT_RAW);
+}
+
+static void mxs_lradc_map_channel(struct mxs_lradc *lradc, unsigned vch,
+ unsigned ch)
+{
+ mxs_lradc_reg_clear(lradc, LRADC_CTRL4_LRADCSELECT_MASK(vch),
+ LRADC_CTRL4);
+ mxs_lradc_reg_set(lradc, LRADC_CTRL4_LRADCSELECT(vch, ch), LRADC_CTRL4);
+}
+
+static void mxs_lradc_setup_ts_channel(struct mxs_lradc *lradc, unsigned ch)
+{
+ /*
+ * prepare for oversampling conversion
+ *
+ * from the datasheet:
+ * "The ACCUMULATE bit in the appropriate channel register
+ * HW_LRADC_CHn must be set to 1 if NUM_SAMPLES is greater then 0;
+ * otherwise, the IRQs will not fire."
+ */
+ mxs_lradc_reg_wrt(lradc, LRADC_CH_ACCUMULATE |
+ LRADC_CH_NUM_SAMPLES(lradc->over_sample_cnt - 1),
+ LRADC_CH(ch));
+
+ /*
+ * from the datasheet:
+ * "Software must clear this register in preparation for a
+ * multi-cycle accumulation.
+ */
+ mxs_lradc_reg_clear(lradc, LRADC_CH_VALUE_MASK, LRADC_CH(ch));
+
+ /*
+ * prepare the delay/loop unit according to the oversampling count
+ *
+ * from the datasheet:
+ * "The DELAY fields in HW_LRADC_DELAY0, HW_LRADC_DELAY1,
+ * HW_LRADC_DELAY2, and HW_LRADC_DELAY3 must be non-zero; otherwise,
+ * the LRADC will not trigger the delay group."
+ */
+ mxs_lradc_reg_wrt(lradc, LRADC_DELAY_TRIGGER(1 << ch) |
+ LRADC_DELAY_TRIGGER_DELAYS(0) |
+ LRADC_DELAY_LOOP(lradc->over_sample_cnt - 1) |
+ LRADC_DELAY_DELAY(lradc->over_sample_delay - 1),
+ LRADC_DELAY(3));
+
+ mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ(ch), LRADC_CTRL1);
+
+ /*
+ * after changing the touchscreen plates setting
+ * the signals need some initial time to settle. Start the
+ * SoC's delay unit and start the conversion later
+ * and automatically.
+ */
+ mxs_lradc_reg_wrt(
+ lradc,
+ LRADC_DELAY_TRIGGER(0) | /* don't trigger ADC */
+ LRADC_DELAY_TRIGGER_DELAYS(BIT(3)) | /* trigger DELAY unit#3 */
+ LRADC_DELAY_KICK |
+ LRADC_DELAY_DELAY(lradc->settling_delay),
+ LRADC_DELAY(2));
+}
+
+/*
+ * Pressure detection is special:
+ * We want to do both required measurements for the pressure detection in
+ * one turn. Use the hardware features to chain both conversions and let the
+ * hardware report one interrupt if both conversions are done
+ */
+static void mxs_lradc_setup_ts_pressure(struct mxs_lradc *lradc, unsigned ch1,
+ unsigned ch2)
+{
+ u32 reg;
+
+ /*
+ * prepare for oversampling conversion
+ *
+ * from the datasheet:
+ * "The ACCUMULATE bit in the appropriate channel register
+ * HW_LRADC_CHn must be set to 1 if NUM_SAMPLES is greater then 0;
+ * otherwise, the IRQs will not fire."
+ */
+ reg = LRADC_CH_ACCUMULATE |
+ LRADC_CH_NUM_SAMPLES(lradc->over_sample_cnt - 1);
+ mxs_lradc_reg_wrt(lradc, reg, LRADC_CH(ch1));
+ mxs_lradc_reg_wrt(lradc, reg, LRADC_CH(ch2));
+
+ /*
+ * from the datasheet:
+ * "Software must clear this register in preparation for a
+ * multi-cycle accumulation.
+ */
+ mxs_lradc_reg_clear(lradc, LRADC_CH_VALUE_MASK, LRADC_CH(ch1));
+ mxs_lradc_reg_clear(lradc, LRADC_CH_VALUE_MASK, LRADC_CH(ch2));
+
+ /* prepare the delay/loop unit according to the oversampling count */
+ mxs_lradc_reg_wrt(
+ lradc,
+ LRADC_DELAY_TRIGGER(1 << ch1) |
+ LRADC_DELAY_TRIGGER(1 << ch2) | /* start both channels */
+ LRADC_DELAY_TRIGGER_DELAYS(0) |
+ LRADC_DELAY_LOOP(lradc->over_sample_cnt - 1) |
+ LRADC_DELAY_DELAY(lradc->over_sample_delay - 1),
+ LRADC_DELAY(3));
+
+ mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ(ch2), LRADC_CTRL1);
+
+ /*
+ * after changing the touchscreen plates setting
+ * the signals need some initial time to settle. Start the
+ * SoC's delay unit and start the conversion later
+ * and automatically.
+ */
+ mxs_lradc_reg_wrt(
+ lradc,
+ LRADC_DELAY_TRIGGER(0) | /* don't trigger ADC */
+ LRADC_DELAY_TRIGGER_DELAYS(BIT(3)) | /* trigger DELAY unit#3 */
+ LRADC_DELAY_KICK |
+ LRADC_DELAY_DELAY(lradc->settling_delay), LRADC_DELAY(2));
+}
+
+static unsigned mxs_lradc_read_raw_channel(struct mxs_lradc *lradc,
+ unsigned channel)
+{
+ u32 reg;
+ unsigned num_samples, val;
+
+ reg = readl(lradc->base + LRADC_CH(channel));
+ if (reg & LRADC_CH_ACCUMULATE)
+ num_samples = lradc->over_sample_cnt;
+ else
+ num_samples = 1;
+
+ val = (reg & LRADC_CH_VALUE_MASK) >> LRADC_CH_VALUE_OFFSET;
+ return val / num_samples;
+}
+
+static unsigned mxs_lradc_read_ts_pressure(struct mxs_lradc *lradc,
+ unsigned ch1, unsigned ch2)
+{
+ u32 reg, mask;
+ unsigned pressure, m1, m2;
+
+ mask = LRADC_CTRL1_LRADC_IRQ(ch1) | LRADC_CTRL1_LRADC_IRQ(ch2);
+ reg = readl(lradc->base + LRADC_CTRL1) & mask;
+
+ while (reg != mask) {
+ reg = readl(lradc->base + LRADC_CTRL1) & mask;
+ dev_dbg(lradc->dev, "One channel is still busy: %X\n", reg);
+ }
+
+ m1 = mxs_lradc_read_raw_channel(lradc, ch1);
+ m2 = mxs_lradc_read_raw_channel(lradc, ch2);
+
+ if (m2 == 0) {
+ dev_warn(lradc->dev, "Cannot calculate pressure\n");
+ return 1 << (LRADC_RESOLUTION - 1);
+ }
+
+ /* simply scale the value from 0 ... max ADC resolution */
+ pressure = m1;
+ pressure *= (1 << LRADC_RESOLUTION);
+ pressure /= m2;
+
+ dev_dbg(lradc->dev, "Pressure = %u\n", pressure);
+ return pressure;
+}
+
+#define TS_CH_XP 2
+#define TS_CH_YP 3
+#define TS_CH_XM 4
+#define TS_CH_YM 5
+
+/*
+ * YP(open)--+-------------+
+ * | |--+
+ * | | |
+ * YM(-)--+-------------+ |
+ * +--------------+
+ * | |
+ * XP(weak+) XM(open)
+ *
+ * "weak+" means 200k Ohm VDDIO
+ * (-) means GND
+ */
+static void mxs_lradc_setup_touch_detection(struct mxs_lradc *lradc)
+{
+ /*
+ * In order to detect a touch event the 'touch detect enable' bit
+ * enables:
+ * - a weak pullup to the X+ connector
+ * - a strong ground at the Y- connector
+ */
+ mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
+ mxs_lradc_reg_set(lradc, mxs_lradc_touch_detect_bit(lradc),
+ LRADC_CTRL0);
+}
+
+/*
+ * YP(meas)--+-------------+
+ * | |--+
+ * | | |
+ * YM(open)--+-------------+ |
+ * +--------------+
+ * | |
+ * XP(+) XM(-)
+ *
+ * (+) means here 1.85 V
+ * (-) means here GND
+ */
+static void mxs_lradc_prepare_x_pos(struct mxs_lradc *lradc)
+{
+ mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
+ mxs_lradc_reg_set(lradc, mxs_lradc_drive_x_plate(lradc), LRADC_CTRL0);
+
+ lradc->cur_plate = LRADC_SAMPLE_X;
+ mxs_lradc_map_channel(lradc, TOUCHSCREEN_VCHANNEL1, TS_CH_YP);
+ mxs_lradc_setup_ts_channel(lradc, TOUCHSCREEN_VCHANNEL1);
+}
+
+/*
+ * YP(+)--+-------------+
+ * | |--+
+ * | | |
+ * YM(-)--+-------------+ |
+ * +--------------+
+ * | |
+ * XP(open) XM(meas)
+ *
+ * (+) means here 1.85 V
+ * (-) means here GND
+ */
+static void mxs_lradc_prepare_y_pos(struct mxs_lradc *lradc)
+{
+ mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
+ mxs_lradc_reg_set(lradc, mxs_lradc_drive_y_plate(lradc), LRADC_CTRL0);
+
+ lradc->cur_plate = LRADC_SAMPLE_Y;
+ mxs_lradc_map_channel(lradc, TOUCHSCREEN_VCHANNEL1, TS_CH_XM);
+ mxs_lradc_setup_ts_channel(lradc, TOUCHSCREEN_VCHANNEL1);
+}
+
+/*
+ * YP(+)--+-------------+
+ * | |--+
+ * | | |
+ * YM(meas)--+-------------+ |
+ * +--------------+
+ * | |
+ * XP(meas) XM(-)
+ *
+ * (+) means here 1.85 V
+ * (-) means here GND
+ */
+static void mxs_lradc_prepare_pressure(struct mxs_lradc *lradc)
+{
+ mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
+ mxs_lradc_reg_set(lradc, mxs_lradc_drive_pressure(lradc), LRADC_CTRL0);
+
+ lradc->cur_plate = LRADC_SAMPLE_PRESSURE;
+ mxs_lradc_map_channel(lradc, TOUCHSCREEN_VCHANNEL1, TS_CH_YM);
+ mxs_lradc_map_channel(lradc, TOUCHSCREEN_VCHANNEL2, TS_CH_XP);
+ mxs_lradc_setup_ts_pressure(lradc, TOUCHSCREEN_VCHANNEL2,
+ TOUCHSCREEN_VCHANNEL1);
+}
+
+static void mxs_lradc_enable_touch_detection(struct mxs_lradc *lradc)
+{
+ mxs_lradc_setup_touch_detection(lradc);
+
+ lradc->cur_plate = LRADC_TOUCH;
+ mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ |
+ LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
+ mxs_lradc_reg_set(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
+}
+
+static void mxs_lradc_start_touch_event(struct mxs_lradc *lradc)
+{
+ mxs_lradc_reg_clear(lradc,
+ LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
+ LRADC_CTRL1);
+ mxs_lradc_reg_set(lradc,
+ LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1),
+ LRADC_CTRL1);
+ /*
+ * start with the Y-pos, because it uses nearly the same plate
+ * settings like the touch detection
+ */
+ mxs_lradc_prepare_y_pos(lradc);
+}
+
+static void mxs_lradc_report_ts_event(struct mxs_lradc *lradc)
+{
+ input_report_abs(lradc->ts_input, ABS_X, lradc->ts_x_pos);
+ input_report_abs(lradc->ts_input, ABS_Y, lradc->ts_y_pos);
+ input_report_abs(lradc->ts_input, ABS_PRESSURE, lradc->ts_pressure);
+ input_report_key(lradc->ts_input, BTN_TOUCH, 1);
+ input_sync(lradc->ts_input);
+}
+
+static void mxs_lradc_complete_touch_event(struct mxs_lradc *lradc)
+{
+ mxs_lradc_setup_touch_detection(lradc);
+ lradc->cur_plate = LRADC_SAMPLE_VALID;
+ /*
+ * start a dummy conversion to burn time to settle the signals
+ * note: we are not interested in the conversion's value
+ */
+ mxs_lradc_reg_wrt(lradc, 0, LRADC_CH(TOUCHSCREEN_VCHANNEL1));
+ mxs_lradc_reg_clear(lradc,
+ LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) |
+ LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2),
+ LRADC_CTRL1);
+ mxs_lradc_reg_wrt(
+ lradc,
+ LRADC_DELAY_TRIGGER(1 << TOUCHSCREEN_VCHANNEL1) |
+ LRADC_DELAY_KICK | LRADC_DELAY_DELAY(10), /* waste 5 ms */
+ LRADC_DELAY(2));
+}
+
+/*
+ * in order to avoid false measurements, report only samples where
+ * the surface is still touched after the position measurement
+ */
+static void mxs_lradc_finish_touch_event(struct mxs_lradc *lradc, bool valid)
+{
+ /* if it is still touched, report the sample */
+ if (valid && mxs_lradc_check_touch_event(lradc)) {
+ lradc->ts_valid = true;
+ mxs_lradc_report_ts_event(lradc);
+ }
+
+ /* if it is even still touched, continue with the next measurement */
+ if (mxs_lradc_check_touch_event(lradc)) {
+ mxs_lradc_prepare_y_pos(lradc);
+ return;
+ }
+
+ if (lradc->ts_valid) {
+ /* signal the release */
+ lradc->ts_valid = false;
+ input_report_key(lradc->ts_input, BTN_TOUCH, 0);
+ input_sync(lradc->ts_input);
+ }
+
+ /* if it is released, wait for the next touch via IRQ */
+ lradc->cur_plate = LRADC_TOUCH;
+ mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(2));
+ mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(3));
+ mxs_lradc_reg_clear(lradc,
+ LRADC_CTRL1_TOUCH_DETECT_IRQ |
+ LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1) |
+ LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1),
+ LRADC_CTRL1);
+ mxs_lradc_reg_set(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
+}
+
+/* touchscreen's state machine */
+static void mxs_lradc_handle_touch(struct mxs_lradc *lradc)
+{
+ switch (lradc->cur_plate) {
+ case LRADC_TOUCH:
+ if (mxs_lradc_check_touch_event(lradc))
+ mxs_lradc_start_touch_event(lradc);
+ mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ,
+ LRADC_CTRL1);
+ return;
+
+ case LRADC_SAMPLE_Y:
+ lradc->ts_y_pos =
+ mxs_lradc_read_raw_channel(lradc,
+ TOUCHSCREEN_VCHANNEL1);
+ mxs_lradc_prepare_x_pos(lradc);
+ return;
+
+ case LRADC_SAMPLE_X:
+ lradc->ts_x_pos =
+ mxs_lradc_read_raw_channel(lradc,
+ TOUCHSCREEN_VCHANNEL1);
+ mxs_lradc_prepare_pressure(lradc);
+ return;
+
+ case LRADC_SAMPLE_PRESSURE:
+ lradc->ts_pressure =
+ mxs_lradc_read_ts_pressure(lradc,
+ TOUCHSCREEN_VCHANNEL2,
+ TOUCHSCREEN_VCHANNEL1);
+ mxs_lradc_complete_touch_event(lradc);
+ return;
+
+ case LRADC_SAMPLE_VALID:
+ mxs_lradc_finish_touch_event(lradc, 1);
+ break;
+ }
+}
+
+/*
+ * Raw I/O operations
+ */
+static int mxs_lradc_read_single(struct iio_dev *iio_dev, int chan, int *val)
+{
+ struct mxs_lradc *lradc = iio_priv(iio_dev);
+ int ret;
+
+ /*
+ * See if there is no buffered operation in progress. 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;
+
+ reinit_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.
+ */
+ if (lradc->soc == IMX28_LRADC)
+ mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ_EN(0),
+ LRADC_CTRL1);
+ mxs_lradc_reg_clear(lradc, 0x1, LRADC_CTRL0);
+
+ /* Enable / disable the divider per requirement */
+ if (test_bit(chan, &lradc->is_divided))
+ mxs_lradc_reg_set(lradc,
+ 1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET,
+ LRADC_CTRL2);
+ else
+ mxs_lradc_reg_clear(lradc,
+ 1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET,
+ LRADC_CTRL2);
+
+ /* Clean the slot's previous content, then set new one. */
+ mxs_lradc_reg_clear(lradc, LRADC_CTRL4_LRADCSELECT_MASK(0),
+ LRADC_CTRL4);
+ mxs_lradc_reg_set(lradc, chan, LRADC_CTRL4);
+
+ mxs_lradc_reg_wrt(lradc, 0, LRADC_CH(0));
+
+ /* Enable the IRQ and start sampling the channel. */
+ mxs_lradc_reg_set(lradc, LRADC_CTRL1_LRADC_IRQ_EN(0), LRADC_CTRL1);
+ mxs_lradc_reg_set(lradc, BIT(0), LRADC_CTRL0);
+
+ /* 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:
+ mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ_EN(0), LRADC_CTRL1);
+
+ mutex_unlock(&lradc->lock);
+
+ return ret;
+}
+
+static int mxs_lradc_read_temp(struct iio_dev *iio_dev, int *val)
+{
+ int ret, min, max;
+
+ ret = mxs_lradc_read_single(iio_dev, 8, &min);
+ if (ret != IIO_VAL_INT)
+ return ret;
+
+ ret = mxs_lradc_read_single(iio_dev, 9, &max);
+ if (ret != IIO_VAL_INT)
+ return ret;
+
+ *val = max - min;
+
+ return IIO_VAL_INT;
+}
+
+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);
+
+ switch (m) {
+ case IIO_CHAN_INFO_RAW:
+ if (chan->type == IIO_TEMP)
+ return mxs_lradc_read_temp(iio_dev, val);
+
+ return mxs_lradc_read_single(iio_dev, chan->channel, val);
+
+ case IIO_CHAN_INFO_SCALE:
+ if (chan->type == IIO_TEMP) {
+ /*
+ * From the datasheet, we have to multiply by 1.012 and
+ * divide by 4
+ */
+ *val = 0;
+ *val2 = 253000;
+ return IIO_VAL_INT_PLUS_MICRO;
+ }
+
+ *val = lradc->vref_mv[chan->channel];
+ *val2 = chan->scan_type.realbits -
+ test_bit(chan->channel, &lradc->is_divided);
+ return IIO_VAL_FRACTIONAL_LOG2;
+
+ case IIO_CHAN_INFO_OFFSET:
+ if (chan->type == IIO_TEMP) {
+ /*
+ * The calculated value from the ADC is in Kelvin, we
+ * want Celsius for hwmon so the offset is -273.15
+ * The offset is applied before scaling so it is
+ * actually -213.15 * 4 / 1.012 = -1079.644268
+ */
+ *val = -1079;
+ *val2 = 644268;
+
+ return IIO_VAL_INT_PLUS_MICRO;
+ }
+
+ return -EINVAL;
+
+ default:
+ break;
+ }
+
+ return -EINVAL;
+}
+
+static int mxs_lradc_write_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);
+ struct mxs_lradc_scale *scale_avail =
+ lradc->scale_avail[chan->channel];
+ int ret;
+
+ ret = mutex_trylock(&lradc->lock);
+ if (!ret)
+ return -EBUSY;
+
+ switch (m) {
+ case IIO_CHAN_INFO_SCALE:
+ ret = -EINVAL;
+ if (val == scale_avail[MXS_LRADC_DIV_DISABLED].integer &&
+ val2 == scale_avail[MXS_LRADC_DIV_DISABLED].nano) {
+ /* divider by two disabled */
+ clear_bit(chan->channel, &lradc->is_divided);
+ ret = 0;
+ } else if (val == scale_avail[MXS_LRADC_DIV_ENABLED].integer &&
+ val2 == scale_avail[MXS_LRADC_DIV_ENABLED].nano) {
+ /* divider by two enabled */
+ set_bit(chan->channel, &lradc->is_divided);
+ ret = 0;
+ }
+
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ mutex_unlock(&lradc->lock);
+
+ return ret;
+}
+
+static int mxs_lradc_write_raw_get_fmt(struct iio_dev *iio_dev,
+ const struct iio_chan_spec *chan,
+ long m)
+{
+ return IIO_VAL_INT_PLUS_NANO;
+}
+
+static ssize_t mxs_lradc_show_scale_available_ch(struct device *dev,
+ struct device_attribute *attr,
+ char *buf,
+ int ch)
+{
+ struct iio_dev *iio = dev_to_iio_dev(dev);
+ struct mxs_lradc *lradc = iio_priv(iio);
+ int i, len = 0;
+
+ for (i = 0; i < ARRAY_SIZE(lradc->scale_avail[ch]); i++)
+ len += sprintf(buf + len, "%u.%09u ",
+ lradc->scale_avail[ch][i].integer,
+ lradc->scale_avail[ch][i].nano);
+
+ len += sprintf(buf + len, "\n");
+
+ return len;
+}
+
+static ssize_t mxs_lradc_show_scale_available(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev_attr *iio_attr = to_iio_dev_attr(attr);
+
+ return mxs_lradc_show_scale_available_ch(dev, attr, buf,
+ iio_attr->address);
+}
+
+#define SHOW_SCALE_AVAILABLE_ATTR(ch) \
+static IIO_DEVICE_ATTR(in_voltage##ch##_scale_available, S_IRUGO, \
+ mxs_lradc_show_scale_available, NULL, ch)
+
+SHOW_SCALE_AVAILABLE_ATTR(0);
+SHOW_SCALE_AVAILABLE_ATTR(1);
+SHOW_SCALE_AVAILABLE_ATTR(2);
+SHOW_SCALE_AVAILABLE_ATTR(3);
+SHOW_SCALE_AVAILABLE_ATTR(4);
+SHOW_SCALE_AVAILABLE_ATTR(5);
+SHOW_SCALE_AVAILABLE_ATTR(6);
+SHOW_SCALE_AVAILABLE_ATTR(7);
+SHOW_SCALE_AVAILABLE_ATTR(10);
+SHOW_SCALE_AVAILABLE_ATTR(11);
+SHOW_SCALE_AVAILABLE_ATTR(12);
+SHOW_SCALE_AVAILABLE_ATTR(13);
+SHOW_SCALE_AVAILABLE_ATTR(14);
+SHOW_SCALE_AVAILABLE_ATTR(15);
+
+static struct attribute *mxs_lradc_attributes[] = {
+ &iio_dev_attr_in_voltage0_scale_available.dev_attr.attr,
+ &iio_dev_attr_in_voltage1_scale_available.dev_attr.attr,
+ &iio_dev_attr_in_voltage2_scale_available.dev_attr.attr,
+ &iio_dev_attr_in_voltage3_scale_available.dev_attr.attr,
+ &iio_dev_attr_in_voltage4_scale_available.dev_attr.attr,
+ &iio_dev_attr_in_voltage5_scale_available.dev_attr.attr,
+ &iio_dev_attr_in_voltage6_scale_available.dev_attr.attr,
+ &iio_dev_attr_in_voltage7_scale_available.dev_attr.attr,
+ &iio_dev_attr_in_voltage10_scale_available.dev_attr.attr,
+ &iio_dev_attr_in_voltage11_scale_available.dev_attr.attr,
+ &iio_dev_attr_in_voltage12_scale_available.dev_attr.attr,
+ &iio_dev_attr_in_voltage13_scale_available.dev_attr.attr,
+ &iio_dev_attr_in_voltage14_scale_available.dev_attr.attr,
+ &iio_dev_attr_in_voltage15_scale_available.dev_attr.attr,
+ NULL
+};
+
+static const struct attribute_group mxs_lradc_attribute_group = {
+ .attrs = mxs_lradc_attributes,
+};
+
+static const struct iio_info mxs_lradc_iio_info = {
+ .driver_module = THIS_MODULE,
+ .read_raw = mxs_lradc_read_raw,
+ .write_raw = mxs_lradc_write_raw,
+ .write_raw_get_fmt = mxs_lradc_write_raw_get_fmt,
+ .attrs = &mxs_lradc_attribute_group,
+};
+
+static int mxs_lradc_ts_open(struct input_dev *dev)
+{
+ struct mxs_lradc *lradc = input_get_drvdata(dev);
+
+ /* Enable the touch-detect circuitry. */
+ mxs_lradc_enable_touch_detection(lradc);
+
+ return 0;
+}
+
+static void mxs_lradc_disable_ts(struct mxs_lradc *lradc)
+{
+ /* stop all interrupts from firing */
+ mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN |
+ LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1) |
+ LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL2), LRADC_CTRL1);
+
+ /* Power-down touchscreen touch-detect circuitry. */
+ mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
+}
+
+static void mxs_lradc_ts_close(struct input_dev *dev)
+{
+ struct mxs_lradc *lradc = input_get_drvdata(dev);
+
+ mxs_lradc_disable_ts(lradc);
+}
+
+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)
+ 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;
+
+ mxs_lradc_disable_ts(lradc);
+ 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);
+ u32 clr_irq = mxs_lradc_irq_mask(lradc);
+ const u32 ts_irq_mask =
+ LRADC_CTRL1_TOUCH_DETECT_IRQ |
+ LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) |
+ LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2);
+
+ if (!(reg & mxs_lradc_irq_mask(lradc)))
+ return IRQ_NONE;
+
+ if (lradc->use_touchscreen && (reg & ts_irq_mask)) {
+ mxs_lradc_handle_touch(lradc);
+
+ /* Make sure we don't clear the next conversion's interrupt. */
+ clr_irq &= ~(LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) |
+ LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2));
+ }
+
+ if (iio_buffer_enabled(iio)) {
+ if (reg & lradc->buffer_vchans)
+ iio_trigger_poll(iio->trig);
+ } else if (reg & LRADC_CTRL1_LRADC_IRQ(0)) {
+ complete(&lradc->completion);
+ }
+
+ mxs_lradc_reg_clear(lradc, reg & clr_irq, LRADC_CTRL1);
+
+ 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 u32 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));
+ mxs_lradc_reg_wrt(lradc, chan_value, 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 u32 st = state ? STMP_OFFSET_REG_SET : STMP_OFFSET_REG_CLR;
+
+ mxs_lradc_reg_wrt(lradc, LRADC_DELAY_KICK, 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)
+ 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;
+ u32 ctrl4_set = 0;
+ u32 ctrl4_clr = 0;
+ u32 ctrl1_irq = 0;
+ const u32 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_array(len, sizeof(*lradc->buffer), GFP_KERNEL);
+ if (!lradc->buffer) {
+ ret = -ENOMEM;
+ goto err_mem;
+ }
+
+ if (lradc->soc == IMX28_LRADC)
+ mxs_lradc_reg_clear(
+ lradc,
+ lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET,
+ LRADC_CTRL1);
+ mxs_lradc_reg_clear(lradc, lradc->buffer_vchans, LRADC_CTRL0);
+
+ 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);
+ mxs_lradc_reg_wrt(lradc, chan_value, LRADC_CH(ofs));
+ bitmap_set(&enable, ofs, 1);
+ ofs++;
+ }
+
+ mxs_lradc_reg_clear(lradc, LRADC_DELAY_TRIGGER_LRADCS_MASK |
+ LRADC_DELAY_KICK, LRADC_DELAY(0));
+ mxs_lradc_reg_clear(lradc, ctrl4_clr, LRADC_CTRL4);
+ mxs_lradc_reg_set(lradc, ctrl4_set, LRADC_CTRL4);
+ mxs_lradc_reg_set(lradc, ctrl1_irq, LRADC_CTRL1);
+ mxs_lradc_reg_set(lradc, enable << LRADC_DELAY_TRIGGER_LRADCS_OFFSET,
+ LRADC_DELAY(0));
+
+ return 0;
+
+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);
+
+ mxs_lradc_reg_clear(lradc, LRADC_DELAY_TRIGGER_LRADCS_MASK |
+ LRADC_DELAY_KICK, LRADC_DELAY(0));
+
+ mxs_lradc_reg_clear(lradc, lradc->buffer_vchans, LRADC_CTRL0);
+ if (lradc->soc == IMX28_LRADC)
+ mxs_lradc_reg_clear(
+ lradc,
+ lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET,
+ LRADC_CTRL1);
+
+ 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 += 2;
+
+ /* 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, name) { \
+ .type = (chan_type), \
+ .indexed = 1, \
+ .scan_index = (idx), \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+ BIT(IIO_CHAN_INFO_SCALE), \
+ .channel = (idx), \
+ .address = (idx), \
+ .scan_type = { \
+ .sign = 'u', \
+ .realbits = LRADC_RESOLUTION, \
+ .storagebits = 32, \
+ }, \
+ .datasheet_name = (name), \
+}
+
+static const struct iio_chan_spec mx23_lradc_chan_spec[] = {
+ MXS_ADC_CHAN(0, IIO_VOLTAGE, "LRADC0"),
+ MXS_ADC_CHAN(1, IIO_VOLTAGE, "LRADC1"),
+ MXS_ADC_CHAN(2, IIO_VOLTAGE, "LRADC2"),
+ MXS_ADC_CHAN(3, IIO_VOLTAGE, "LRADC3"),
+ MXS_ADC_CHAN(4, IIO_VOLTAGE, "LRADC4"),
+ MXS_ADC_CHAN(5, IIO_VOLTAGE, "LRADC5"),
+ MXS_ADC_CHAN(6, IIO_VOLTAGE, "VDDIO"),
+ MXS_ADC_CHAN(7, IIO_VOLTAGE, "VBATT"),
+ /* Combined Temperature sensors */
+ {
+ .type = IIO_TEMP,
+ .indexed = 1,
+ .scan_index = 8,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_OFFSET) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .channel = 8,
+ .scan_type = {.sign = 'u', .realbits = 18, .storagebits = 32,},
+ .datasheet_name = "TEMP_DIE",
+ },
+ /* Hidden channel to keep indexes */
+ {
+ .type = IIO_TEMP,
+ .indexed = 1,
+ .scan_index = -1,
+ .channel = 9,
+ },
+ MXS_ADC_CHAN(10, IIO_VOLTAGE, NULL),
+ MXS_ADC_CHAN(11, IIO_VOLTAGE, NULL),
+ MXS_ADC_CHAN(12, IIO_VOLTAGE, "USB_DP"),
+ MXS_ADC_CHAN(13, IIO_VOLTAGE, "USB_DN"),
+ MXS_ADC_CHAN(14, IIO_VOLTAGE, "VBG"),
+ MXS_ADC_CHAN(15, IIO_VOLTAGE, "VDD5V"),
+};
+
+static const struct iio_chan_spec mx28_lradc_chan_spec[] = {
+ MXS_ADC_CHAN(0, IIO_VOLTAGE, "LRADC0"),
+ MXS_ADC_CHAN(1, IIO_VOLTAGE, "LRADC1"),
+ MXS_ADC_CHAN(2, IIO_VOLTAGE, "LRADC2"),
+ MXS_ADC_CHAN(3, IIO_VOLTAGE, "LRADC3"),
+ MXS_ADC_CHAN(4, IIO_VOLTAGE, "LRADC4"),
+ MXS_ADC_CHAN(5, IIO_VOLTAGE, "LRADC5"),
+ MXS_ADC_CHAN(6, IIO_VOLTAGE, "LRADC6"),
+ MXS_ADC_CHAN(7, IIO_VOLTAGE, "VBATT"),
+ /* Combined Temperature sensors */
+ {
+ .type = IIO_TEMP,
+ .indexed = 1,
+ .scan_index = 8,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_OFFSET) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .channel = 8,
+ .scan_type = {.sign = 'u', .realbits = 18, .storagebits = 32,},
+ .datasheet_name = "TEMP_DIE",
+ },
+ /* Hidden channel to keep indexes */
+ {
+ .type = IIO_TEMP,
+ .indexed = 1,
+ .scan_index = -1,
+ .channel = 9,
+ },
+ 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 u32 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. */
+ mxs_lradc_reg_wrt(lradc, adc_cfg, LRADC_DELAY(0));
+
+ /* Disable remaining DELAY CHANNELs */
+ mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(1));
+ mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(2));
+ mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(3));
+
+ /* Configure the touchscreen type */
+ if (lradc->soc == IMX28_LRADC) {
+ mxs_lradc_reg_clear(lradc, LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE,
+ LRADC_CTRL0);
+
+ if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_5WIRE)
+ mxs_lradc_reg_set(lradc, LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE,
+ LRADC_CTRL0);
+ }
+
+ /* Start internal temperature sensing. */
+ mxs_lradc_reg_wrt(lradc, 0, LRADC_CTRL2);
+
+ return 0;
+}
+
+static void mxs_lradc_hw_stop(struct mxs_lradc *lradc)
+{
+ int i;
+
+ mxs_lradc_reg_clear(lradc, mxs_lradc_irq_en_mask(lradc), LRADC_CTRL1);
+
+ for (i = 0; i < LRADC_MAX_DELAY_CHANS; i++)
+ mxs_lradc_reg_wrt(lradc, 0, 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_touchscreen(struct mxs_lradc *lradc,
+ struct device_node *lradc_node)
+{
+ int ret;
+ u32 ts_wires = 0, adapt;
+
+ ret = of_property_read_u32(lradc_node, "fsl,lradc-touchscreen-wires",
+ &ts_wires);
+ if (ret)
+ return -ENODEV; /* touchscreen feature disabled */
+
+ switch (ts_wires) {
+ case 4:
+ lradc->use_touchscreen = MXS_LRADC_TOUCHSCREEN_4WIRE;
+ break;
+ case 5:
+ if (lradc->soc == IMX28_LRADC) {
+ lradc->use_touchscreen = MXS_LRADC_TOUCHSCREEN_5WIRE;
+ break;
+ }
+ /* fall through an error message for i.MX23 */
+ default:
+ dev_err(lradc->dev,
+ "Unsupported number of touchscreen wires (%d)\n",
+ ts_wires);
+ return -EINVAL;
+ }
+
+ if (of_property_read_u32(lradc_node, "fsl,ave-ctrl", &adapt)) {
+ lradc->over_sample_cnt = 4;
+ } else {
+ if (adapt < 1 || adapt > 32) {
+ dev_err(lradc->dev, "Invalid sample count (%u)\n",
+ adapt);
+ return -EINVAL;
+ }
+ lradc->over_sample_cnt = adapt;
+ }
+
+ if (of_property_read_u32(lradc_node, "fsl,ave-delay", &adapt)) {
+ lradc->over_sample_delay = 2;
+ } else {
+ if (adapt < 2 || adapt > LRADC_DELAY_DELAY_MASK + 1) {
+ dev_err(lradc->dev, "Invalid sample delay (%u)\n",
+ adapt);
+ return -EINVAL;
+ }
+ lradc->over_sample_delay = adapt;
+ }
+
+ if (of_property_read_u32(lradc_node, "fsl,settling", &adapt)) {
+ lradc->settling_delay = 10;
+ } else {
+ if (adapt < 1 || adapt > LRADC_DELAY_DELAY_MASK) {
+ dev_err(lradc->dev, "Invalid settling delay (%u)\n",
+ adapt);
+ return -EINVAL;
+ }
+ lradc->settling_delay = adapt;
+ }
+
+ return 0;
+}
+
+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;
+ int ret = 0, touch_ret;
+ int i, s;
+ u64 scale_uv;
+
+ /* 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);
+ lradc->soc = (enum mxs_lradc_id)of_id->data;
+
+ /* 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;
+ }
+
+ touch_ret = mxs_lradc_probe_touchscreen(lradc, node);
+
+ if (touch_ret == 0)
+ lradc->buffer_vchans = BUFFER_VCHANS_LIMITED;
+ else
+ lradc->buffer_vchans = BUFFER_VCHANS_ALL;
+
+ /* 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) {
+ ret = lradc->irq[i];
+ goto err_clk;
+ }
+
+ ret = devm_request_irq(dev, lradc->irq[i],
+ mxs_lradc_handle_irq, 0,
+ of_cfg->irq_name[i], iio);
+ if (ret)
+ goto err_clk;
+ }
+
+ lradc->vref_mv = of_cfg->vref_mv;
+
+ 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->masklength = LRADC_MAX_TOTAL_CHANS;
+
+ if (lradc->soc == IMX23_LRADC) {
+ iio->channels = mx23_lradc_chan_spec;
+ iio->num_channels = ARRAY_SIZE(mx23_lradc_chan_spec);
+ } else {
+ iio->channels = mx28_lradc_chan_spec;
+ iio->num_channels = ARRAY_SIZE(mx28_lradc_chan_spec);
+ }
+
+ ret = iio_triggered_buffer_setup(iio, &iio_pollfunc_store_time,
+ &mxs_lradc_trigger_handler,
+ &mxs_lradc_buffer_ops);
+ if (ret)
+ goto err_clk;
+
+ ret = mxs_lradc_trigger_init(iio);
+ if (ret)
+ goto err_trig;
+
+ /* Populate available ADC input ranges */
+ for (i = 0; i < LRADC_MAX_TOTAL_CHANS; i++) {
+ for (s = 0; s < ARRAY_SIZE(lradc->scale_avail[i]); s++) {
+ /*
+ * [s=0] = optional divider by two disabled (default)
+ * [s=1] = optional divider by two enabled
+ *
+ * The scale is calculated by doing:
+ * Vref >> (realbits - s)
+ * which multiplies by two on the second component
+ * of the array.
+ */
+ scale_uv = ((u64)lradc->vref_mv[i] * 100000000) >>
+ (LRADC_RESOLUTION - s);
+ lradc->scale_avail[i][s].nano =
+ do_div(scale_uv, 100000000) * 10;
+ lradc->scale_avail[i][s].integer = scale_uv;
+ }
+ }
+
+ /* Configure the hardware. */
+ ret = mxs_lradc_hw_init(lradc);
+ if (ret)
+ goto err_dev;
+
+ /* Register the touchscreen input device. */
+ if (touch_ret == 0) {
+ 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);
+err_clk:
+ clk_disable_unprepare(lradc->clk);
+ 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,
+ .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 MXS LRADC driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRIVER_NAME);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-18 00:08:19 +0000