From 84882b060301c35ab7e2c1ef355b0bd06b764195 Mon Sep 17 00:00:00 2001 From: Alexandre Belloni Date: Tue, 15 Apr 2014 12:27:59 +0200 Subject: [PATCH] iio: adc: at91_adc: Add support for touchscreens without TSMR Old ADCs, as present on the sam9rl and the sam9g45 don't have a TSMR register and the touchscreen support should be handled differently. Signed-off-by: Alexandre Belloni Acked-by: Jonathan Cameron Signed-off-by: Nicolas Ferre --- arch/arm/mach-at91/include/mach/at91_adc.h | 13 ++ drivers/iio/adc/at91_adc.c | 200 ++++++++++++++++++++++------- include/linux/platform_data/at91_adc.h | 8 ++ 3 files changed, 174 insertions(+), 47 deletions(-) diff --git a/arch/arm/mach-at91/include/mach/at91_adc.h b/arch/arm/mach-at91/include/mach/at91_adc.h index c287307b9a3b..7d80396346b2 100644 --- a/arch/arm/mach-at91/include/mach/at91_adc.h +++ b/arch/arm/mach-at91/include/mach/at91_adc.h @@ -20,6 +20,9 @@ #define AT91_ADC_START (1 << 1) /* Start Conversion */ #define AT91_ADC_MR 0x04 /* Mode Register */ +#define AT91_ADC_TSAMOD (3 << 0) /* ADC mode */ +#define AT91_ADC_TSAMOD_ADC_ONLY_MODE (0 << 0) /* ADC Mode */ +#define AT91_ADC_TSAMOD_TS_ONLY_MODE (1 << 0) /* Touch Screen Only Mode */ #define AT91_ADC_TRGEN (1 << 0) /* Trigger Enable */ #define AT91_ADC_TRGSEL (7 << 1) /* Trigger Selection */ #define AT91_ADC_TRGSEL_TC0 (0 << 1) @@ -28,6 +31,7 @@ #define AT91_ADC_TRGSEL_EXTERNAL (6 << 1) #define AT91_ADC_LOWRES (1 << 4) /* Low Resolution */ #define AT91_ADC_SLEEP (1 << 5) /* Sleep Mode */ +#define AT91_ADC_PENDET (1 << 6) /* Pen contact detection enable */ #define AT91_ADC_PRESCAL_9260 (0x3f << 8) /* Prescalar Rate Selection */ #define AT91_ADC_PRESCAL_9G45 (0xff << 8) #define AT91_ADC_PRESCAL_(x) ((x) << 8) @@ -37,6 +41,12 @@ #define AT91_ADC_STARTUP_(x) ((x) << 16) #define AT91_ADC_SHTIM (0xf << 24) /* Sample & Hold Time */ #define AT91_ADC_SHTIM_(x) ((x) << 24) +#define AT91_ADC_PENDBC (0x0f << 28) /* Pen Debounce time */ +#define AT91_ADC_PENDBC_(x) ((x) << 28) + +#define AT91_ADC_TSR 0x0C +#define AT91_ADC_TSR_SHTIM (0xf << 24) /* Sample & Hold Time */ +#define AT91_ADC_TSR_SHTIM_(x) ((x) << 24) #define AT91_ADC_CHER 0x10 /* Channel Enable Register */ #define AT91_ADC_CHDR 0x14 /* Channel Disable Register */ @@ -60,6 +70,8 @@ #define AT91_ADC_IER 0x24 /* Interrupt Enable Register */ #define AT91_ADC_IDR 0x28 /* Interrupt Disable Register */ #define AT91_ADC_IMR 0x2C /* Interrupt Mask Register */ +#define AT91RL_ADC_IER_PEN (1 << 20) +#define AT91RL_ADC_IER_NOPEN (1 << 21) #define AT91_ADC_IER_PEN (1 << 29) #define AT91_ADC_IER_NOPEN (1 << 30) #define AT91_ADC_IER_XRDY (1 << 20) @@ -102,6 +114,7 @@ #define AT91_ADC_TRGR_TRGPER (0xffff << 16) #define AT91_ADC_TRGR_TRGPER_(x) ((x) << 16) #define AT91_ADC_TRGR_TRGMOD (0x7 << 0) +#define AT91_ADC_TRGR_NONE (0 << 0) #define AT91_ADC_TRGR_MOD_PERIOD_TRIG (5 << 0) #endif diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c index 1beae65aef2c..c0e4206e34e5 100644 --- a/drivers/iio/adc/at91_adc.c +++ b/drivers/iio/adc/at91_adc.c @@ -46,6 +46,10 @@ #define TOUCH_SAMPLE_PERIOD_US 2000 /* 2ms */ #define TOUCH_PEN_DETECT_DEBOUNCE_US 200 +#define MAX_RLPOS_BITS 10 +#define TOUCH_SAMPLE_PERIOD_US_RL 10000 /* 10ms, the SoC can't keep up with 2ms */ +#define TOUCH_SHTIM 0xa + /** * struct at91_adc_reg_desc - Various informations relative to registers * @channel_base: Base offset for the channel data registers @@ -83,12 +87,6 @@ struct at91_adc_caps { struct at91_adc_reg_desc registers; }; -enum atmel_adc_ts_type { - ATMEL_ADC_TOUCHSCREEN_NONE = 0, - ATMEL_ADC_TOUCHSCREEN_4WIRE = 4, - ATMEL_ADC_TOUCHSCREEN_5WIRE = 5, -}; - struct at91_adc_state { struct clk *adc_clk; u16 *buffer; @@ -133,6 +131,11 @@ struct at91_adc_state { u16 ts_sample_period_val; u32 ts_pressure_threshold; + u16 ts_pendbc; + + bool ts_bufferedmeasure; + u32 ts_prev_absx; + u32 ts_prev_absy; }; static irqreturn_t at91_adc_trigger_handler(int irq, void *p) @@ -239,7 +242,72 @@ static int at91_ts_sample(struct at91_adc_state *st) return 0; } -static irqreturn_t at91_adc_interrupt(int irq, void *private) +static irqreturn_t at91_adc_rl_interrupt(int irq, void *private) +{ + struct iio_dev *idev = private; + struct at91_adc_state *st = iio_priv(idev); + u32 status = at91_adc_readl(st, st->registers->status_register); + unsigned int reg; + + status &= at91_adc_readl(st, AT91_ADC_IMR); + if (status & st->registers->drdy_mask) + handle_adc_eoc_trigger(irq, idev); + + if (status & AT91RL_ADC_IER_PEN) { + /* Disabling pen debounce is required to get a NOPEN irq */ + reg = at91_adc_readl(st, AT91_ADC_MR); + reg &= ~AT91_ADC_PENDBC; + at91_adc_writel(st, AT91_ADC_MR, reg); + + at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_PEN); + at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_NOPEN + | AT91_ADC_EOC(3)); + /* Set up period trigger for sampling */ + at91_adc_writel(st, st->registers->trigger_register, + AT91_ADC_TRGR_MOD_PERIOD_TRIG | + AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val)); + } else if (status & AT91RL_ADC_IER_NOPEN) { + reg = at91_adc_readl(st, AT91_ADC_MR); + reg |= AT91_ADC_PENDBC_(st->ts_pendbc) & AT91_ADC_PENDBC; + at91_adc_writel(st, AT91_ADC_MR, reg); + at91_adc_writel(st, st->registers->trigger_register, + AT91_ADC_TRGR_NONE); + + at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_NOPEN + | AT91_ADC_EOC(3)); + at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_PEN); + st->ts_bufferedmeasure = false; + input_report_key(st->ts_input, BTN_TOUCH, 0); + input_sync(st->ts_input); + } else if (status & AT91_ADC_EOC(3)) { + /* Conversion finished */ + if (st->ts_bufferedmeasure) { + /* + * Last measurement is always discarded, since it can + * be erroneous. + * Always report previous measurement + */ + input_report_abs(st->ts_input, ABS_X, st->ts_prev_absx); + input_report_abs(st->ts_input, ABS_Y, st->ts_prev_absy); + input_report_key(st->ts_input, BTN_TOUCH, 1); + input_sync(st->ts_input); + } else + st->ts_bufferedmeasure = true; + + /* Now make new measurement */ + st->ts_prev_absx = at91_adc_readl(st, AT91_ADC_CHAN(st, 3)) + << MAX_RLPOS_BITS; + st->ts_prev_absx /= at91_adc_readl(st, AT91_ADC_CHAN(st, 2)); + + st->ts_prev_absy = at91_adc_readl(st, AT91_ADC_CHAN(st, 1)) + << MAX_RLPOS_BITS; + st->ts_prev_absy /= at91_adc_readl(st, AT91_ADC_CHAN(st, 0)); + } + + return IRQ_HANDLED; +} + +static irqreturn_t at91_adc_9x5_interrupt(int irq, void *private) { struct iio_dev *idev = private; struct at91_adc_state *st = iio_priv(idev); @@ -672,6 +740,8 @@ static int at91_adc_probe_dt_ts(struct device_node *node, return -EINVAL; } + if (!st->caps->has_tsmr) + return 0; prop = 0; of_property_read_u32(node, "atmel,adc-ts-pressure-threshold", &prop); st->ts_pressure_threshold = prop; @@ -795,6 +865,7 @@ static int at91_adc_probe_pdata(struct at91_adc_state *st, st->trigger_number = pdata->trigger_number; st->trigger_list = pdata->trigger_list; st->registers = &st->caps->registers; + st->touchscreen_type = pdata->touchscreen_type; return 0; } @@ -809,7 +880,10 @@ static int atmel_ts_open(struct input_dev *dev) { struct at91_adc_state *st = input_get_drvdata(dev); - at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN); + if (st->caps->has_tsmr) + at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN); + else + at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_PEN); return 0; } @@ -817,45 +891,61 @@ static void atmel_ts_close(struct input_dev *dev) { struct at91_adc_state *st = input_get_drvdata(dev); - at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN); + if (st->caps->has_tsmr) + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN); + else + at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_PEN); } static int at91_ts_hw_init(struct at91_adc_state *st, u32 adc_clk_khz) { - u32 reg = 0, pendbc; + u32 reg = 0; int i = 0; - if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE) - reg = AT91_ADC_TSMR_TSMODE_4WIRE_PRESS; - else - reg = AT91_ADC_TSMR_TSMODE_5WIRE; - /* a Pen Detect Debounce Time is necessary for the ADC Touch to avoid * pen detect noise. * The formula is : Pen Detect Debounce Time = (2 ^ pendbc) / ADCClock */ - pendbc = round_up(TOUCH_PEN_DETECT_DEBOUNCE_US * adc_clk_khz / 1000, 1); + st->ts_pendbc = round_up(TOUCH_PEN_DETECT_DEBOUNCE_US * adc_clk_khz / + 1000, 1); - while (pendbc >> ++i) + while (st->ts_pendbc >> ++i) ; /* Empty! Find the shift offset */ - if (abs(pendbc - (1 << i)) < abs(pendbc - (1 << (i - 1)))) - pendbc = i; + if (abs(st->ts_pendbc - (1 << i)) < abs(st->ts_pendbc - (1 << (i - 1)))) + st->ts_pendbc = i; else - pendbc = i - 1; + st->ts_pendbc = i - 1; - if (st->caps->has_tsmr) { - reg |= AT91_ADC_TSMR_TSAV_(st->caps->ts_filter_average) - & AT91_ADC_TSMR_TSAV; - reg |= AT91_ADC_TSMR_PENDBC_(pendbc) & AT91_ADC_TSMR_PENDBC; - reg |= AT91_ADC_TSMR_NOTSDMA; - reg |= AT91_ADC_TSMR_PENDET_ENA; - reg |= 0x03 << 8; /* TSFREQ, need bigger than TSAV */ - - at91_adc_writel(st, AT91_ADC_TSMR, reg); - } else { - /* TODO: for 9g45 which has no TSMR */ + if (!st->caps->has_tsmr) { + reg = at91_adc_readl(st, AT91_ADC_MR); + reg |= AT91_ADC_TSAMOD_TS_ONLY_MODE | AT91_ADC_PENDET; + + reg |= AT91_ADC_PENDBC_(st->ts_pendbc) & AT91_ADC_PENDBC; + at91_adc_writel(st, AT91_ADC_MR, reg); + + reg = AT91_ADC_TSR_SHTIM_(TOUCH_SHTIM) & AT91_ADC_TSR_SHTIM; + at91_adc_writel(st, AT91_ADC_TSR, reg); + + st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US_RL * + adc_clk_khz / 1000) - 1, 1); + + return 0; } + if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE) + reg = AT91_ADC_TSMR_TSMODE_4WIRE_PRESS; + else + reg = AT91_ADC_TSMR_TSMODE_5WIRE; + + reg |= AT91_ADC_TSMR_TSAV_(st->caps->ts_filter_average) + & AT91_ADC_TSMR_TSAV; + reg |= AT91_ADC_TSMR_PENDBC_(st->ts_pendbc) & AT91_ADC_TSMR_PENDBC; + reg |= AT91_ADC_TSMR_NOTSDMA; + reg |= AT91_ADC_TSMR_PENDET_ENA; + reg |= 0x03 << 8; /* TSFREQ, needs to be bigger than TSAV */ + + at91_adc_writel(st, AT91_ADC_TSMR, reg); + /* Change adc internal resistor value for better pen detection, * default value is 100 kOhm. * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm @@ -864,7 +954,7 @@ static int at91_ts_hw_init(struct at91_adc_state *st, u32 adc_clk_khz) at91_adc_writel(st, AT91_ADC_ACR, st->caps->ts_pen_detect_sensitivity & AT91_ADC_ACR_PENDETSENS); - /* Sample Peroid Time = (TRGPER + 1) / ADCClock */ + /* Sample Period Time = (TRGPER + 1) / ADCClock */ st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US * adc_clk_khz / 1000) - 1, 1); @@ -893,17 +983,37 @@ static int at91_ts_register(struct at91_adc_state *st, __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, (1 << MAX_POS_BITS) - 1, 0, 0); - input_set_abs_params(input, ABS_Y, 0, (1 << MAX_POS_BITS) - 1, 0, 0); - input_set_abs_params(input, ABS_PRESSURE, 0, 0xffffff, 0, 0); + if (st->caps->has_tsmr) { + input_set_abs_params(input, ABS_X, 0, (1 << MAX_POS_BITS) - 1, + 0, 0); + input_set_abs_params(input, ABS_Y, 0, (1 << MAX_POS_BITS) - 1, + 0, 0); + input_set_abs_params(input, ABS_PRESSURE, 0, 0xffffff, 0, 0); + } else { + if (st->touchscreen_type != ATMEL_ADC_TOUCHSCREEN_4WIRE) { + dev_err(&pdev->dev, + "This touchscreen controller only support 4 wires\n"); + ret = -EINVAL; + goto err; + } + + input_set_abs_params(input, ABS_X, 0, (1 << MAX_RLPOS_BITS) - 1, + 0, 0); + input_set_abs_params(input, ABS_Y, 0, (1 << MAX_RLPOS_BITS) - 1, + 0, 0); + } st->ts_input = input; input_set_drvdata(input, st); ret = input_register_device(input); if (ret) - input_free_device(st->ts_input); + goto err; + + return ret; +err: + input_free_device(st->ts_input); return ret; } @@ -962,11 +1072,13 @@ static int at91_adc_probe(struct platform_device *pdev) */ at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_SWRST); at91_adc_writel(st, AT91_ADC_IDR, 0xFFFFFFFF); - ret = request_irq(st->irq, - at91_adc_interrupt, - 0, - pdev->dev.driver->name, - idev); + + if (st->caps->has_tsmr) + ret = request_irq(st->irq, at91_adc_9x5_interrupt, 0, + pdev->dev.driver->name, idev); + else + ret = request_irq(st->irq, at91_adc_rl_interrupt, 0, + pdev->dev.driver->name, idev); if (ret) { dev_err(&pdev->dev, "Failed to allocate IRQ.\n"); return ret; @@ -1070,12 +1182,6 @@ static int at91_adc_probe(struct platform_device *pdev) goto error_disable_adc_clk; } } else { - if (!st->caps->has_tsmr) { - dev_err(&pdev->dev, "We don't support non-TSMR adc\n"); - ret = -ENODEV; - goto error_disable_adc_clk; - } - ret = at91_ts_register(st, pdev); if (ret) goto error_disable_adc_clk; diff --git a/include/linux/platform_data/at91_adc.h b/include/linux/platform_data/at91_adc.h index fcf73879dbfe..7819fc787731 100644 --- a/include/linux/platform_data/at91_adc.h +++ b/include/linux/platform_data/at91_adc.h @@ -7,6 +7,12 @@ #ifndef _AT91_ADC_H_ #define _AT91_ADC_H_ +enum atmel_adc_ts_type { + ATMEL_ADC_TOUCHSCREEN_NONE = 0, + ATMEL_ADC_TOUCHSCREEN_4WIRE = 4, + ATMEL_ADC_TOUCHSCREEN_5WIRE = 5, +}; + /** * struct at91_adc_trigger - description of triggers * @name: name of the trigger advertised to the user @@ -28,6 +34,7 @@ struct at91_adc_trigger { * @trigger_number: Number of triggers available in the ADC * @use_external_triggers: does the board has external triggers availables * @vref: Reference voltage for the ADC in millivolts + * @touchscreen_type: If a touchscreen is connected, its type (4 or 5 wires) */ struct at91_adc_data { unsigned long channels_used; @@ -36,6 +43,7 @@ struct at91_adc_data { u8 trigger_number; bool use_external_triggers; u16 vref; + enum atmel_adc_ts_type touchscreen_type; }; extern void __init at91_add_device_adc(struct at91_adc_data *data); -- 2.11.0