diff options
| -rw-r--r-- | Documentation/devicetree/bindings/arm/atmel-adc.txt | 7 | ||||
| -rw-r--r-- | arch/arm/mach-at91/include/mach/at91_adc.h | 34 | ||||
| -rw-r--r-- | drivers/iio/adc/at91_adc.c | 388 |
3 files changed, 405 insertions, 24 deletions
diff --git a/Documentation/devicetree/bindings/arm/atmel-adc.txt b/Documentation/devicetree/bindings/arm/atmel-adc.txt index 0e65e0137487..d1061469f63d 100644 --- a/Documentation/devicetree/bindings/arm/atmel-adc.txt +++ b/Documentation/devicetree/bindings/arm/atmel-adc.txt @@ -23,6 +23,13 @@ Optional properties: resolution will be used. - atmel,adc-sleep-mode: Boolean to enable sleep mode when no conversion - atmel,adc-sample-hold-time: Sample and Hold Time in microseconds + - atmel,adc-ts-wires: Number of touch screen wires. Should be 4 or 5. If this + value is set, then adc driver will enable touch screen + support. + NOTE: when adc touch screen enabled, the adc hardware trigger will be + disabled. Since touch screen will occupied the trigger register. + - atmel,adc-ts-pressure-threshold: a pressure threshold for touchscreen. It + make touch detect more precision. Optional trigger Nodes: - Required properties: diff --git a/arch/arm/mach-at91/include/mach/at91_adc.h b/arch/arm/mach-at91/include/mach/at91_adc.h index 048a57f76bd3..c287307b9a3b 100644 --- a/arch/arm/mach-at91/include/mach/at91_adc.h +++ b/arch/arm/mach-at91/include/mach/at91_adc.h @@ -60,14 +60,48 @@ #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 AT91_ADC_IER_PEN (1 << 29) +#define AT91_ADC_IER_NOPEN (1 << 30) +#define AT91_ADC_IER_XRDY (1 << 20) +#define AT91_ADC_IER_YRDY (1 << 21) +#define AT91_ADC_IER_PRDY (1 << 22) +#define AT91_ADC_ISR_PENS (1 << 31) #define AT91_ADC_CHR(n) (0x30 + ((n) * 4)) /* Channel Data Register N */ #define AT91_ADC_DATA (0x3ff) #define AT91_ADC_CDR0_9X5 (0x50) /* Channel Data Register 0 for 9X5 */ +#define AT91_ADC_ACR 0x94 /* Analog Control Register */ +#define AT91_ADC_ACR_PENDETSENS (0x3 << 0) /* pull-up resistor */ + +#define AT91_ADC_TSMR 0xB0 +#define AT91_ADC_TSMR_TSMODE (3 << 0) /* Touch Screen Mode */ +#define AT91_ADC_TSMR_TSMODE_NONE (0 << 0) +#define AT91_ADC_TSMR_TSMODE_4WIRE_NO_PRESS (1 << 0) +#define AT91_ADC_TSMR_TSMODE_4WIRE_PRESS (2 << 0) +#define AT91_ADC_TSMR_TSMODE_5WIRE (3 << 0) +#define AT91_ADC_TSMR_TSAV (3 << 4) /* Averages samples */ +#define AT91_ADC_TSMR_TSAV_(x) ((x) << 4) +#define AT91_ADC_TSMR_SCTIM (0x0f << 16) /* Switch closure time */ +#define AT91_ADC_TSMR_PENDBC (0x0f << 28) /* Pen Debounce time */ +#define AT91_ADC_TSMR_PENDBC_(x) ((x) << 28) +#define AT91_ADC_TSMR_NOTSDMA (1 << 22) /* No Touchscreen DMA */ +#define AT91_ADC_TSMR_PENDET_DIS (0 << 24) /* Pen contact detection disable */ +#define AT91_ADC_TSMR_PENDET_ENA (1 << 24) /* Pen contact detection enable */ + +#define AT91_ADC_TSXPOSR 0xB4 +#define AT91_ADC_TSYPOSR 0xB8 +#define AT91_ADC_TSPRESSR 0xBC + #define AT91_ADC_TRGR_9260 AT91_ADC_MR #define AT91_ADC_TRGR_9G45 0x08 #define AT91_ADC_TRGR_9X5 0xC0 +/* Trigger Register bit field */ +#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_MOD_PERIOD_TRIG (5 << 0) + #endif diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c index 690a560e0dab..17df74908db1 100644 --- a/drivers/iio/adc/at91_adc.c +++ b/drivers/iio/adc/at91_adc.c @@ -11,6 +11,7 @@ #include <linux/clk.h> #include <linux/err.h> #include <linux/io.h> +#include <linux/input.h> #include <linux/interrupt.h> #include <linux/jiffies.h> #include <linux/kernel.h> @@ -39,7 +40,23 @@ #define at91_adc_writel(st, reg, val) \ (writel_relaxed(val, st->reg_base + reg)) +#define DRIVER_NAME "at91_adc" +#define MAX_POS_BITS 12 + +#define TOUCH_SAMPLE_PERIOD_US 2000 /* 2ms */ +#define TOUCH_PEN_DETECT_DEBOUNCE_US 200 + struct at91_adc_caps { + bool has_ts; /* Support touch screen */ + bool has_tsmr; /* only at91sam9x5, sama5d3 have TSMR reg */ + /* + * Numbers of sampling data will be averaged. Can be 0~3. + * Hardware can average (2 ^ ts_filter_average) sample data. + */ + u8 ts_filter_average; + /* Pen Detection input pull-up resistor, can be 0~3 */ + u8 ts_pen_detect_sensitivity; + /* startup time calculate function */ u32 (*calc_startup_ticks)(u8 startup_time, u32 adc_clk_khz); @@ -47,6 +64,12 @@ 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; @@ -71,6 +94,26 @@ struct at91_adc_state { bool low_res; /* the resolution corresponds to the lowest one */ wait_queue_head_t wq_data_avail; struct at91_adc_caps *caps; + + /* + * Following ADC channels are shared by touchscreen: + * + * CH0 -- Touch screen XP/UL + * CH1 -- Touch screen XM/UR + * CH2 -- Touch screen YP/LL + * CH3 -- Touch screen YM/Sense + * CH4 -- Touch screen LR(5-wire only) + * + * The bitfields below represents the reserved channel in the + * touchscreen mode. + */ +#define CHAN_MASK_TOUCHSCREEN_4WIRE (0xf << 0) +#define CHAN_MASK_TOUCHSCREEN_5WIRE (0x1f << 0) + enum atmel_adc_ts_type touchscreen_type; + struct input_dev *ts_input; + + u16 ts_sample_period_val; + u32 ts_pressure_threshold; }; static irqreturn_t at91_adc_trigger_handler(int irq, void *p) @@ -99,14 +142,10 @@ static irqreturn_t at91_adc_trigger_handler(int irq, void *p) return IRQ_HANDLED; } -static irqreturn_t at91_adc_eoc_trigger(int irq, void *private) +/* Handler for classic adc channel eoc trigger */ +void handle_adc_eoc_trigger(int irq, struct iio_dev *idev) { - struct iio_dev *idev = private; struct at91_adc_state *st = iio_priv(idev); - u32 status = at91_adc_readl(st, st->registers->status_register); - - if (!(status & st->registers->drdy_mask)) - return IRQ_HANDLED; if (iio_buffer_enabled(idev)) { disable_irq_nosync(irq); @@ -116,6 +155,115 @@ static irqreturn_t at91_adc_eoc_trigger(int irq, void *private) st->done = true; wake_up_interruptible(&st->wq_data_avail); } +} + +static int at91_ts_sample(struct at91_adc_state *st) +{ + unsigned int xscale, yscale, reg, z1, z2; + unsigned int x, y, pres, xpos, ypos; + unsigned int rxp = 1; + unsigned int factor = 1000; + struct iio_dev *idev = iio_priv_to_dev(st); + + unsigned int xyz_mask_bits = st->res; + unsigned int xyz_mask = (1 << xyz_mask_bits) - 1; + + /* calculate position */ + /* x position = (x / xscale) * max, max = 2^MAX_POS_BITS - 1 */ + reg = at91_adc_readl(st, AT91_ADC_TSXPOSR); + xpos = reg & xyz_mask; + x = (xpos << MAX_POS_BITS) - xpos; + xscale = (reg >> 16) & xyz_mask; + if (xscale == 0) { + dev_err(&idev->dev, "Error: xscale == 0!\n"); + return -1; + } + x /= xscale; + + /* y position = (y / yscale) * max, max = 2^MAX_POS_BITS - 1 */ + reg = at91_adc_readl(st, AT91_ADC_TSYPOSR); + ypos = reg & xyz_mask; + y = (ypos << MAX_POS_BITS) - ypos; + yscale = (reg >> 16) & xyz_mask; + if (yscale == 0) { + dev_err(&idev->dev, "Error: yscale == 0!\n"); + return -1; + } + y /= yscale; + + /* calculate the pressure */ + reg = at91_adc_readl(st, AT91_ADC_TSPRESSR); + z1 = reg & xyz_mask; + z2 = (reg >> 16) & xyz_mask; + + if (z1 != 0) + pres = rxp * (x * factor / 1024) * (z2 * factor / z1 - factor) + / factor; + else + pres = st->ts_pressure_threshold; /* no pen contacted */ + + dev_dbg(&idev->dev, "xpos = %d, xscale = %d, ypos = %d, yscale = %d, z1 = %d, z2 = %d, press = %d\n", + xpos, xscale, ypos, yscale, z1, z2, pres); + + if (pres < st->ts_pressure_threshold) { + dev_dbg(&idev->dev, "x = %d, y = %d, pressure = %d\n", + x, y, pres / factor); + input_report_abs(st->ts_input, ABS_X, x); + input_report_abs(st->ts_input, ABS_Y, y); + input_report_abs(st->ts_input, ABS_PRESSURE, pres); + input_report_key(st->ts_input, BTN_TOUCH, 1); + input_sync(st->ts_input); + } else { + dev_dbg(&idev->dev, "pressure too low: not reporting\n"); + } + + return 0; +} + +static irqreturn_t at91_adc_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); + const uint32_t ts_data_irq_mask = + AT91_ADC_IER_XRDY | + AT91_ADC_IER_YRDY | + AT91_ADC_IER_PRDY; + + if (status & st->registers->drdy_mask) + handle_adc_eoc_trigger(irq, idev); + + if (status & AT91_ADC_IER_PEN) { + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN); + at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_NOPEN | + ts_data_irq_mask); + /* 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 & AT91_ADC_IER_NOPEN) { + at91_adc_writel(st, st->registers->trigger_register, 0); + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_NOPEN | + ts_data_irq_mask); + at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN); + + input_report_key(st->ts_input, BTN_TOUCH, 0); + input_sync(st->ts_input); + } else if ((status & ts_data_irq_mask) == ts_data_irq_mask) { + /* Now all touchscreen data is ready */ + + if (status & AT91_ADC_ISR_PENS) { + /* validate data by pen contact */ + at91_ts_sample(st); + } else { + /* triggered by event that is no pen contact, just read + * them to clean the interrupt and discard all. + */ + at91_adc_readl(st, AT91_ADC_TSXPOSR); + at91_adc_readl(st, AT91_ADC_TSYPOSR); + at91_adc_readl(st, AT91_ADC_TSPRESSR); + } + } return IRQ_HANDLED; } @@ -125,6 +273,16 @@ static int at91_adc_channel_init(struct iio_dev *idev) struct at91_adc_state *st = iio_priv(idev); struct iio_chan_spec *chan_array, *timestamp; int bit, idx = 0; + unsigned long rsvd_mask = 0; + + /* If touchscreen is enable, then reserve the adc channels */ + if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE) + rsvd_mask = CHAN_MASK_TOUCHSCREEN_4WIRE; + else if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_5WIRE) + rsvd_mask = CHAN_MASK_TOUCHSCREEN_5WIRE; + + /* set up the channel mask to reserve touchscreen channels */ + st->channels_mask &= ~rsvd_mask; idev->num_channels = bitmap_weight(&st->channels_mask, st->num_channels) + 1; @@ -473,6 +631,39 @@ static u32 calc_startup_ticks_9x5(u8 startup_time, u32 adc_clk_khz) static const struct of_device_id at91_adc_dt_ids[]; +static int at91_adc_probe_dt_ts(struct device_node *node, + struct at91_adc_state *st, struct device *dev) +{ + int ret; + u32 prop; + + ret = of_property_read_u32(node, "atmel,adc-ts-wires", &prop); + if (ret) { + dev_info(dev, "ADC Touch screen is disabled.\n"); + return 0; + } + + switch (prop) { + case 4: + case 5: + st->touchscreen_type = prop; + break; + default: + dev_err(dev, "Unsupported number of touchscreen wires (%d). Should be 4 or 5.\n", prop); + return -EINVAL; + } + + prop = 0; + of_property_read_u32(node, "atmel,adc-ts-pressure-threshold", &prop); + st->ts_pressure_threshold = prop; + if (st->ts_pressure_threshold) { + return 0; + } else { + dev_err(dev, "Invalid pressure threshold for the touchscreen\n"); + return -EINVAL; + } +} + static int at91_adc_probe_dt(struct at91_adc_state *st, struct platform_device *pdev) { @@ -554,6 +745,12 @@ static int at91_adc_probe_dt(struct at91_adc_state *st, i++; } + /* Check if touchscreen is supported. */ + if (st->caps->has_ts) + return at91_adc_probe_dt_ts(node, st, &idev->dev); + else + dev_info(&idev->dev, "not support touchscreen in the adc compatible string.\n"); + return 0; error_ret: @@ -585,6 +782,114 @@ static const struct iio_info at91_adc_info = { .read_raw = &at91_adc_read_raw, }; +/* Touchscreen related functions */ +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); + return 0; +} + +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); +} + +static int at91_ts_hw_init(struct at91_adc_state *st, u32 adc_clk_khz) +{ + u32 reg = 0, pendbc; + 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); + + while (pendbc >> ++i) + ; /* Empty! Find the shift offset */ + if (abs(pendbc - (1 << i)) < abs(pendbc - (1 << (i - 1)))) + pendbc = i; + else + 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 */ + } + + /* 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 + * option only available on ES2 and higher + */ + at91_adc_writel(st, AT91_ADC_ACR, st->caps->ts_pen_detect_sensitivity + & AT91_ADC_ACR_PENDETSENS); + + /* Sample Peroid Time = (TRGPER + 1) / ADCClock */ + st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US * + adc_clk_khz / 1000) - 1, 1); + + return 0; +} + +static int at91_ts_register(struct at91_adc_state *st, + struct platform_device *pdev) +{ + struct input_dev *input; + struct iio_dev *idev = iio_priv_to_dev(st); + int ret; + + input = input_allocate_device(); + if (!input) { + dev_err(&idev->dev, "Failed to allocate TS device!\n"); + return -ENOMEM; + } + + input->name = DRIVER_NAME; + input->id.bustype = BUS_HOST; + input->dev.parent = &pdev->dev; + input->open = atmel_ts_open; + input->close = atmel_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, (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); + + st->ts_input = input; + input_set_drvdata(input, st); + + ret = input_register_device(input); + if (ret) + input_free_device(st->ts_input); + + return ret; +} + +static void at91_ts_unregister(struct at91_adc_state *st) +{ + input_unregister_device(st->ts_input); +} + static int at91_adc_probe(struct platform_device *pdev) { unsigned int prsc, mstrclk, ticks, adc_clk, adc_clk_khz, shtim; @@ -636,7 +941,7 @@ 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_eoc_trigger, + at91_adc_interrupt, 0, pdev->dev.driver->name, idev); @@ -681,6 +986,10 @@ static int at91_adc_probe(struct platform_device *pdev) mstrclk = clk_get_rate(st->clk); adc_clk = clk_get_rate(st->adc_clk); adc_clk_khz = adc_clk / 1000; + + dev_dbg(&pdev->dev, "Master clock is set as: %d Hz, adc_clk should set as: %d Hz\n", + mstrclk, adc_clk); + prsc = (mstrclk / (2 * adc_clk)) - 1; if (!st->startup_time) { @@ -717,30 +1026,52 @@ static int at91_adc_probe(struct platform_device *pdev) init_waitqueue_head(&st->wq_data_avail); mutex_init(&st->lock); - ret = at91_adc_buffer_init(idev); - if (ret < 0) { - dev_err(&pdev->dev, "Couldn't initialize the buffer.\n"); - goto error_disable_adc_clk; - } + /* + * Since touch screen will set trigger register as period trigger. So + * when touch screen is enabled, then we have to disable hardware + * trigger for classic adc. + */ + if (!st->touchscreen_type) { + ret = at91_adc_buffer_init(idev); + if (ret < 0) { + dev_err(&pdev->dev, "Couldn't initialize the buffer.\n"); + goto error_disable_adc_clk; + } - ret = at91_adc_trigger_init(idev); - if (ret < 0) { - dev_err(&pdev->dev, "Couldn't setup the triggers.\n"); - goto error_unregister_buffer; + ret = at91_adc_trigger_init(idev); + if (ret < 0) { + dev_err(&pdev->dev, "Couldn't setup the triggers.\n"); + at91_adc_buffer_remove(idev); + goto error_disable_adc_clk; + } + } else { + if (!st->caps->has_tsmr) { + dev_err(&pdev->dev, "We don't support non-TSMR adc\n"); + goto error_disable_adc_clk; + } + + ret = at91_ts_register(st, pdev); + if (ret) + goto error_disable_adc_clk; + + at91_ts_hw_init(st, adc_clk_khz); } ret = iio_device_register(idev); if (ret < 0) { dev_err(&pdev->dev, "Couldn't register the device.\n"); - goto error_remove_triggers; + goto error_iio_device_register; } return 0; -error_remove_triggers: - at91_adc_trigger_remove(idev); -error_unregister_buffer: - at91_adc_buffer_remove(idev); +error_iio_device_register: + if (!st->touchscreen_type) { + at91_adc_trigger_remove(idev); + at91_adc_buffer_remove(idev); + } else { + at91_ts_unregister(st); + } error_disable_adc_clk: clk_disable_unprepare(st->adc_clk); error_disable_clk: @@ -756,8 +1087,12 @@ static int at91_adc_remove(struct platform_device *pdev) struct at91_adc_state *st = iio_priv(idev); iio_device_unregister(idev); - at91_adc_trigger_remove(idev); - at91_adc_buffer_remove(idev); + if (!st->touchscreen_type) { + at91_adc_trigger_remove(idev); + at91_adc_buffer_remove(idev); + } else { + at91_ts_unregister(st); + } clk_disable_unprepare(st->adc_clk); clk_disable_unprepare(st->clk); free_irq(st->irq, idev); @@ -780,6 +1115,7 @@ static struct at91_adc_caps at91sam9260_caps = { }; static struct at91_adc_caps at91sam9g45_caps = { + .has_ts = true, .calc_startup_ticks = calc_startup_ticks_9260, /* same as 9260 */ .num_channels = 8, .registers = { @@ -793,6 +1129,10 @@ static struct at91_adc_caps at91sam9g45_caps = { }; static struct at91_adc_caps at91sam9x5_caps = { + .has_ts = true, + .has_tsmr = true, + .ts_filter_average = 3, + .ts_pen_detect_sensitivity = 2, .calc_startup_ticks = calc_startup_ticks_9x5, .num_channels = 12, .registers = { @@ -819,7 +1159,7 @@ static struct platform_driver at91_adc_driver = { .probe = at91_adc_probe, .remove = at91_adc_remove, .driver = { - .name = "at91_adc", + .name = DRIVER_NAME, .of_match_table = of_match_ptr(at91_adc_dt_ids), }, }; |