diff options
Diffstat (limited to 'drivers/iio/adc/mxs-lradc.c')
| -rw-r--r-- | drivers/iio/adc/mxs-lradc.c | 1775 |
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); |