/* * Freescale i.MX28 LRADC driver * * Copyright (c) 2012 DENX Software Engineering, GmbH. * Marek Vasut * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define DRIVER_NAME "mxs-lradc" #define LRADC_MAX_DELAY_CHANS 4 #define LRADC_MAX_MAPPED_CHANS 8 #define LRADC_MAX_TOTAL_CHANS 16 #define LRADC_DELAY_TIMER_HZ 2000 /* * Make this runtime configurable if necessary. Currently, if the buffered mode * is enabled, the LRADC takes LRADC_DELAY_TIMER_LOOP samples of data before * triggering IRQ. The sampling happens every (LRADC_DELAY_TIMER_PER / 2000) * seconds. The result is that the samples arrive every 500mS. */ #define LRADC_DELAY_TIMER_PER 200 #define LRADC_DELAY_TIMER_LOOP 5 /* * Once the pen touches the touchscreen, the touchscreen switches from * IRQ-driven mode to polling mode to prevent interrupt storm. The polling * is realized by worker thread, which is called every 20 or so milliseconds. * This gives the touchscreen enough fluence and does not strain the system * too much. */ #define LRADC_TS_SAMPLE_DELAY_MS 5 /* * The LRADC reads the following amount of samples from each touchscreen * channel and the driver then computes avarage of these. */ #define LRADC_TS_SAMPLE_AMOUNT 4 enum mxs_lradc_id { IMX23_LRADC, IMX28_LRADC, }; static const char * const mx23_lradc_irq_names[] = { "mxs-lradc-touchscreen", "mxs-lradc-channel0", "mxs-lradc-channel1", "mxs-lradc-channel2", "mxs-lradc-channel3", "mxs-lradc-channel4", "mxs-lradc-channel5", "mxs-lradc-channel6", "mxs-lradc-channel7", }; static const char * const mx28_lradc_irq_names[] = { "mxs-lradc-touchscreen", "mxs-lradc-thresh0", "mxs-lradc-thresh1", "mxs-lradc-channel0", "mxs-lradc-channel1", "mxs-lradc-channel2", "mxs-lradc-channel3", "mxs-lradc-channel4", "mxs-lradc-channel5", "mxs-lradc-channel6", "mxs-lradc-channel7", "mxs-lradc-button0", "mxs-lradc-button1", }; struct mxs_lradc_of_config { const int irq_count; const char * const *irq_name; const uint32_t *vref_mv; }; #define VREF_MV_BASE 1850 static const uint32_t 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 uint32_t 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; uint32_t *buffer; struct iio_trigger *trig; struct mutex lock; struct completion completion; const uint32_t *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 bitfields below represents which parts of the LRADC block are * switched into special mode of operation. These channels can not * be sampled as regular LRADC channels. The driver will refuse any * attempt to sample these channels. */ #define CHAN_MASK_TOUCHBUTTON (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; /* statemachine */ 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 (0xff << 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 (1 << 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 progess. If there is, simply * bail out. This can be improved to support both buffered and raw IO at * the same time, yet the code becomes horribly complicated. Therefore I * applied KISS principle here. */ ret = mutex_trylock(&lradc->lock); if (!ret) return -EBUSY; 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 * -272.15 * scale */ *val = -1075; *val2 = 691699; 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); uint32_t clr_irq = mxs_lradc_irq_mask(lradc); const uint32_t 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 uint32_t chan_value = LRADC_CH_ACCUMULATE | ((LRADC_DELAY_TIMER_LOOP - 1) << LRADC_CH_NUM_SAMPLES_OFFSET); unsigned int i, j = 0; for_each_set_bit(i, iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS) { lradc->buffer[j] = readl(lradc->base + LRADC_CH(j)); 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 uint32_t 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 == NULL) return -ENOMEM; trig->dev.parent = lradc->dev; iio_trigger_set_drvdata(trig, iio); trig->ops = &mxs_lradc_trigger_ops; ret = iio_trigger_register(trig); if (ret) { iio_trigger_free(trig); return ret; } lradc->trig = trig; return 0; } static void mxs_lradc_trigger_remove(struct iio_dev *iio) { struct mxs_lradc *lradc = iio_priv(iio); iio_trigger_unregister(lradc->trig); iio_trigger_free(lradc->trig); } static int mxs_lradc_buffer_preenable(struct iio_dev *iio) { struct mxs_lradc *lradc = iio_priv(iio); int ret = 0, chan, ofs = 0; unsigned long enable = 0; uint32_t ctrl4_set = 0; uint32_t ctrl4_clr = 0; uint32_t ctrl1_irq = 0; const uint32_t chan_value = LRADC_CH_ACCUMULATE | ((LRADC_DELAY_TIMER_LOOP - 1) << LRADC_CH_NUM_SAMPLES_OFFSET); const int len = bitmap_weight(iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS); if (!len) return -EINVAL; /* * Lock the driver so raw access can not be done during buffered * operation. This simplifies the code a lot. */ ret = mutex_trylock(&lradc->lock); if (!ret) return -EBUSY; lradc->buffer = kmalloc_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) { \ .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, \ }, \ } static const struct iio_chan_spec mxs_lradc_chan_spec[] = { MXS_ADC_CHAN(0, IIO_VOLTAGE), MXS_ADC_CHAN(1, IIO_VOLTAGE), MXS_ADC_CHAN(2, IIO_VOLTAGE), MXS_ADC_CHAN(3, IIO_VOLTAGE), MXS_ADC_CHAN(4, IIO_VOLTAGE), MXS_ADC_CHAN(5, IIO_VOLTAGE), MXS_ADC_CHAN(6, IIO_VOLTAGE), MXS_ADC_CHAN(7, IIO_VOLTAGE), /* VBATT */ /* 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,}, }, /* 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 uint32_t adc_cfg = (1 << (LRADC_DELAY_TRIGGER_DELAYS_OFFSET + 0)) | (LRADC_DELAY_TIMER_PER << LRADC_DELAY_DELAY_OFFSET); int ret = stmp_reset_block(lradc->base); if (ret) return ret; /* Configure DELAY CHANNEL 0 for generic ADC sampling. */ 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; uint64_t 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->channels = mxs_lradc_chan_spec; iio->num_channels = ARRAY_SIZE(mxs_lradc_chan_spec); iio->masklength = LRADC_MAX_TOTAL_CHANS; ret = iio_triggered_buffer_setup(iio, &iio_pollfunc_store_time, &mxs_lradc_trigger_handler, &mxs_lradc_buffer_ops); if (ret) 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 "); MODULE_DESCRIPTION("Freescale i.MX28 LRADC driver"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:" DRIVER_NAME);