diff options
Diffstat (limited to 'drivers/input/touchscreen/imx6ul_tsc.c')
| -rw-r--r-- | drivers/input/touchscreen/imx6ul_tsc.c | 569 |
1 files changed, 569 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/imx6ul_tsc.c b/drivers/input/touchscreen/imx6ul_tsc.c new file mode 100644 index 000000000..2d4facf70 --- /dev/null +++ b/drivers/input/touchscreen/imx6ul_tsc.c @@ -0,0 +1,569 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// Freescale i.MX6UL touchscreen controller driver +// +// Copyright (C) 2015 Freescale Semiconductor, Inc. + +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/gpio/consumer.h> +#include <linux/input.h> +#include <linux/slab.h> +#include <linux/completion.h> +#include <linux/delay.h> +#include <linux/of.h> +#include <linux/interrupt.h> +#include <linux/platform_device.h> +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/log2.h> + +/* ADC configuration registers field define */ +#define ADC_AIEN (0x1 << 7) +#define ADC_CONV_DISABLE 0x1F +#define ADC_AVGE (0x1 << 5) +#define ADC_CAL (0x1 << 7) +#define ADC_CALF 0x2 +#define ADC_12BIT_MODE (0x2 << 2) +#define ADC_CONV_MODE_MASK (0x3 << 2) +#define ADC_IPG_CLK 0x00 +#define ADC_INPUT_CLK_MASK 0x3 +#define ADC_CLK_DIV_8 (0x03 << 5) +#define ADC_CLK_DIV_MASK (0x3 << 5) +#define ADC_SHORT_SAMPLE_MODE (0x0 << 4) +#define ADC_SAMPLE_MODE_MASK (0x1 << 4) +#define ADC_HARDWARE_TRIGGER (0x1 << 13) +#define ADC_AVGS_SHIFT 14 +#define ADC_AVGS_MASK (0x3 << 14) +#define SELECT_CHANNEL_4 0x04 +#define SELECT_CHANNEL_1 0x01 +#define DISABLE_CONVERSION_INT (0x0 << 7) + +/* ADC registers */ +#define REG_ADC_HC0 0x00 +#define REG_ADC_HC1 0x04 +#define REG_ADC_HC2 0x08 +#define REG_ADC_HC3 0x0C +#define REG_ADC_HC4 0x10 +#define REG_ADC_HS 0x14 +#define REG_ADC_R0 0x18 +#define REG_ADC_CFG 0x2C +#define REG_ADC_GC 0x30 +#define REG_ADC_GS 0x34 + +#define ADC_TIMEOUT msecs_to_jiffies(100) + +/* TSC registers */ +#define REG_TSC_BASIC_SETING 0x00 +#define REG_TSC_PRE_CHARGE_TIME 0x10 +#define REG_TSC_FLOW_CONTROL 0x20 +#define REG_TSC_MEASURE_VALUE 0x30 +#define REG_TSC_INT_EN 0x40 +#define REG_TSC_INT_SIG_EN 0x50 +#define REG_TSC_INT_STATUS 0x60 +#define REG_TSC_DEBUG_MODE 0x70 +#define REG_TSC_DEBUG_MODE2 0x80 + +/* TSC configuration registers field define */ +#define DETECT_4_WIRE_MODE (0x0 << 4) +#define AUTO_MEASURE 0x1 +#define MEASURE_SIGNAL 0x1 +#define DETECT_SIGNAL (0x1 << 4) +#define VALID_SIGNAL (0x1 << 8) +#define MEASURE_INT_EN 0x1 +#define MEASURE_SIG_EN 0x1 +#define VALID_SIG_EN (0x1 << 8) +#define DE_GLITCH_2 (0x2 << 29) +#define START_SENSE (0x1 << 12) +#define TSC_DISABLE (0x1 << 16) +#define DETECT_MODE 0x2 + +struct imx6ul_tsc { + struct device *dev; + struct input_dev *input; + void __iomem *tsc_regs; + void __iomem *adc_regs; + struct clk *tsc_clk; + struct clk *adc_clk; + struct gpio_desc *xnur_gpio; + + u32 measure_delay_time; + u32 pre_charge_time; + bool average_enable; + u32 average_select; + + struct completion completion; +}; + +/* + * TSC module need ADC to get the measure value. So + * before config TSC, we should initialize ADC module. + */ +static int imx6ul_adc_init(struct imx6ul_tsc *tsc) +{ + u32 adc_hc = 0; + u32 adc_gc; + u32 adc_gs; + u32 adc_cfg; + unsigned long timeout; + + reinit_completion(&tsc->completion); + + adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG); + adc_cfg &= ~(ADC_CONV_MODE_MASK | ADC_INPUT_CLK_MASK); + adc_cfg |= ADC_12BIT_MODE | ADC_IPG_CLK; + adc_cfg &= ~(ADC_CLK_DIV_MASK | ADC_SAMPLE_MODE_MASK); + adc_cfg |= ADC_CLK_DIV_8 | ADC_SHORT_SAMPLE_MODE; + if (tsc->average_enable) { + adc_cfg &= ~ADC_AVGS_MASK; + adc_cfg |= (tsc->average_select) << ADC_AVGS_SHIFT; + } + adc_cfg &= ~ADC_HARDWARE_TRIGGER; + writel(adc_cfg, tsc->adc_regs + REG_ADC_CFG); + + /* enable calibration interrupt */ + adc_hc |= ADC_AIEN; + adc_hc |= ADC_CONV_DISABLE; + writel(adc_hc, tsc->adc_regs + REG_ADC_HC0); + + /* start ADC calibration */ + adc_gc = readl(tsc->adc_regs + REG_ADC_GC); + adc_gc |= ADC_CAL; + if (tsc->average_enable) + adc_gc |= ADC_AVGE; + writel(adc_gc, tsc->adc_regs + REG_ADC_GC); + + timeout = wait_for_completion_timeout + (&tsc->completion, ADC_TIMEOUT); + if (timeout == 0) { + dev_err(tsc->dev, "Timeout for adc calibration\n"); + return -ETIMEDOUT; + } + + adc_gs = readl(tsc->adc_regs + REG_ADC_GS); + if (adc_gs & ADC_CALF) { + dev_err(tsc->dev, "ADC calibration failed\n"); + return -EINVAL; + } + + /* TSC need the ADC work in hardware trigger */ + adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG); + adc_cfg |= ADC_HARDWARE_TRIGGER; + writel(adc_cfg, tsc->adc_regs + REG_ADC_CFG); + + return 0; +} + +/* + * This is a TSC workaround. Currently TSC misconnect two + * ADC channels, this function remap channel configure for + * hardware trigger. + */ +static void imx6ul_tsc_channel_config(struct imx6ul_tsc *tsc) +{ + u32 adc_hc0, adc_hc1, adc_hc2, adc_hc3, adc_hc4; + + adc_hc0 = DISABLE_CONVERSION_INT; + writel(adc_hc0, tsc->adc_regs + REG_ADC_HC0); + + adc_hc1 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_4; + writel(adc_hc1, tsc->adc_regs + REG_ADC_HC1); + + adc_hc2 = DISABLE_CONVERSION_INT; + writel(adc_hc2, tsc->adc_regs + REG_ADC_HC2); + + adc_hc3 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_1; + writel(adc_hc3, tsc->adc_regs + REG_ADC_HC3); + + adc_hc4 = DISABLE_CONVERSION_INT; + writel(adc_hc4, tsc->adc_regs + REG_ADC_HC4); +} + +/* + * TSC setting, confige the pre-charge time and measure delay time. + * different touch screen may need different pre-charge time and + * measure delay time. + */ +static void imx6ul_tsc_set(struct imx6ul_tsc *tsc) +{ + u32 basic_setting = 0; + u32 start; + + basic_setting |= tsc->measure_delay_time << 8; + basic_setting |= DETECT_4_WIRE_MODE | AUTO_MEASURE; + writel(basic_setting, tsc->tsc_regs + REG_TSC_BASIC_SETING); + + writel(DE_GLITCH_2, tsc->tsc_regs + REG_TSC_DEBUG_MODE2); + + writel(tsc->pre_charge_time, tsc->tsc_regs + REG_TSC_PRE_CHARGE_TIME); + writel(MEASURE_INT_EN, tsc->tsc_regs + REG_TSC_INT_EN); + writel(MEASURE_SIG_EN | VALID_SIG_EN, + tsc->tsc_regs + REG_TSC_INT_SIG_EN); + + /* start sense detection */ + start = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL); + start |= START_SENSE; + start &= ~TSC_DISABLE; + writel(start, tsc->tsc_regs + REG_TSC_FLOW_CONTROL); +} + +static int imx6ul_tsc_init(struct imx6ul_tsc *tsc) +{ + int err; + + err = imx6ul_adc_init(tsc); + if (err) + return err; + imx6ul_tsc_channel_config(tsc); + imx6ul_tsc_set(tsc); + + return 0; +} + +static void imx6ul_tsc_disable(struct imx6ul_tsc *tsc) +{ + u32 tsc_flow; + u32 adc_cfg; + + /* TSC controller enters to idle status */ + tsc_flow = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL); + tsc_flow |= TSC_DISABLE; + writel(tsc_flow, tsc->tsc_regs + REG_TSC_FLOW_CONTROL); + + /* ADC controller enters to stop mode */ + adc_cfg = readl(tsc->adc_regs + REG_ADC_HC0); + adc_cfg |= ADC_CONV_DISABLE; + writel(adc_cfg, tsc->adc_regs + REG_ADC_HC0); +} + +/* Delay some time (max 2ms), wait the pre-charge done. */ +static bool tsc_wait_detect_mode(struct imx6ul_tsc *tsc) +{ + unsigned long timeout = jiffies + msecs_to_jiffies(2); + u32 state_machine; + u32 debug_mode2; + + do { + if (time_after(jiffies, timeout)) + return false; + + usleep_range(200, 400); + debug_mode2 = readl(tsc->tsc_regs + REG_TSC_DEBUG_MODE2); + state_machine = (debug_mode2 >> 20) & 0x7; + } while (state_machine != DETECT_MODE); + + usleep_range(200, 400); + return true; +} + +static irqreturn_t tsc_irq_fn(int irq, void *dev_id) +{ + struct imx6ul_tsc *tsc = dev_id; + u32 status; + u32 value; + u32 x, y; + u32 start; + + status = readl(tsc->tsc_regs + REG_TSC_INT_STATUS); + + /* write 1 to clear the bit measure-signal */ + writel(MEASURE_SIGNAL | DETECT_SIGNAL, + tsc->tsc_regs + REG_TSC_INT_STATUS); + + /* It's a HW self-clean bit. Set this bit and start sense detection */ + start = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL); + start |= START_SENSE; + writel(start, tsc->tsc_regs + REG_TSC_FLOW_CONTROL); + + if (status & MEASURE_SIGNAL) { + value = readl(tsc->tsc_regs + REG_TSC_MEASURE_VALUE); + x = (value >> 16) & 0x0fff; + y = value & 0x0fff; + + /* + * In detect mode, we can get the xnur gpio value, + * otherwise assume contact is stiull active. + */ + if (!tsc_wait_detect_mode(tsc) || + gpiod_get_value_cansleep(tsc->xnur_gpio)) { + input_report_key(tsc->input, BTN_TOUCH, 1); + input_report_abs(tsc->input, ABS_X, x); + input_report_abs(tsc->input, ABS_Y, y); + } else { + input_report_key(tsc->input, BTN_TOUCH, 0); + } + + input_sync(tsc->input); + } + + return IRQ_HANDLED; +} + +static irqreturn_t adc_irq_fn(int irq, void *dev_id) +{ + struct imx6ul_tsc *tsc = dev_id; + u32 coco; + + coco = readl(tsc->adc_regs + REG_ADC_HS); + if (coco & 0x01) { + readl(tsc->adc_regs + REG_ADC_R0); + complete(&tsc->completion); + } + + return IRQ_HANDLED; +} + +static int imx6ul_tsc_start(struct imx6ul_tsc *tsc) +{ + int err; + + err = clk_prepare_enable(tsc->adc_clk); + if (err) { + dev_err(tsc->dev, + "Could not prepare or enable the adc clock: %d\n", + err); + return err; + } + + err = clk_prepare_enable(tsc->tsc_clk); + if (err) { + dev_err(tsc->dev, + "Could not prepare or enable the tsc clock: %d\n", + err); + goto disable_adc_clk; + } + + err = imx6ul_tsc_init(tsc); + if (err) + goto disable_tsc_clk; + + return 0; + +disable_tsc_clk: + clk_disable_unprepare(tsc->tsc_clk); +disable_adc_clk: + clk_disable_unprepare(tsc->adc_clk); + return err; +} + +static void imx6ul_tsc_stop(struct imx6ul_tsc *tsc) +{ + imx6ul_tsc_disable(tsc); + + clk_disable_unprepare(tsc->tsc_clk); + clk_disable_unprepare(tsc->adc_clk); +} + + +static int imx6ul_tsc_open(struct input_dev *input_dev) +{ + struct imx6ul_tsc *tsc = input_get_drvdata(input_dev); + + return imx6ul_tsc_start(tsc); +} + +static void imx6ul_tsc_close(struct input_dev *input_dev) +{ + struct imx6ul_tsc *tsc = input_get_drvdata(input_dev); + + imx6ul_tsc_stop(tsc); +} + +static int imx6ul_tsc_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct imx6ul_tsc *tsc; + struct input_dev *input_dev; + int err; + int tsc_irq; + int adc_irq; + u32 average_samples; + + tsc = devm_kzalloc(&pdev->dev, sizeof(*tsc), GFP_KERNEL); + if (!tsc) + return -ENOMEM; + + input_dev = devm_input_allocate_device(&pdev->dev); + if (!input_dev) + return -ENOMEM; + + input_dev->name = "iMX6UL Touchscreen Controller"; + input_dev->id.bustype = BUS_HOST; + + input_dev->open = imx6ul_tsc_open; + input_dev->close = imx6ul_tsc_close; + + input_set_capability(input_dev, EV_KEY, BTN_TOUCH); + input_set_abs_params(input_dev, ABS_X, 0, 0xFFF, 0, 0); + input_set_abs_params(input_dev, ABS_Y, 0, 0xFFF, 0, 0); + + input_set_drvdata(input_dev, tsc); + + tsc->dev = &pdev->dev; + tsc->input = input_dev; + init_completion(&tsc->completion); + + tsc->xnur_gpio = devm_gpiod_get(&pdev->dev, "xnur", GPIOD_IN); + if (IS_ERR(tsc->xnur_gpio)) { + err = PTR_ERR(tsc->xnur_gpio); + dev_err(&pdev->dev, + "failed to request GPIO tsc_X- (xnur): %d\n", err); + return err; + } + + tsc->tsc_regs = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(tsc->tsc_regs)) { + err = PTR_ERR(tsc->tsc_regs); + dev_err(&pdev->dev, "failed to remap tsc memory: %d\n", err); + return err; + } + + tsc->adc_regs = devm_platform_ioremap_resource(pdev, 1); + if (IS_ERR(tsc->adc_regs)) { + err = PTR_ERR(tsc->adc_regs); + dev_err(&pdev->dev, "failed to remap adc memory: %d\n", err); + return err; + } + + tsc->tsc_clk = devm_clk_get(&pdev->dev, "tsc"); + if (IS_ERR(tsc->tsc_clk)) { + err = PTR_ERR(tsc->tsc_clk); + dev_err(&pdev->dev, "failed getting tsc clock: %d\n", err); + return err; + } + + tsc->adc_clk = devm_clk_get(&pdev->dev, "adc"); + if (IS_ERR(tsc->adc_clk)) { + err = PTR_ERR(tsc->adc_clk); + dev_err(&pdev->dev, "failed getting adc clock: %d\n", err); + return err; + } + + tsc_irq = platform_get_irq(pdev, 0); + if (tsc_irq < 0) + return tsc_irq; + + adc_irq = platform_get_irq(pdev, 1); + if (adc_irq < 0) + return adc_irq; + + err = devm_request_threaded_irq(tsc->dev, tsc_irq, + NULL, tsc_irq_fn, IRQF_ONESHOT, + dev_name(&pdev->dev), tsc); + if (err) { + dev_err(&pdev->dev, + "failed requesting tsc irq %d: %d\n", + tsc_irq, err); + return err; + } + + err = devm_request_irq(tsc->dev, adc_irq, adc_irq_fn, 0, + dev_name(&pdev->dev), tsc); + if (err) { + dev_err(&pdev->dev, + "failed requesting adc irq %d: %d\n", + adc_irq, err); + return err; + } + + err = of_property_read_u32(np, "measure-delay-time", + &tsc->measure_delay_time); + if (err) + tsc->measure_delay_time = 0xffff; + + err = of_property_read_u32(np, "pre-charge-time", + &tsc->pre_charge_time); + if (err) + tsc->pre_charge_time = 0xfff; + + err = of_property_read_u32(np, "touchscreen-average-samples", + &average_samples); + if (err) + average_samples = 1; + + switch (average_samples) { + case 1: + tsc->average_enable = false; + tsc->average_select = 0; /* value unused; initialize anyway */ + break; + case 4: + case 8: + case 16: + case 32: + tsc->average_enable = true; + tsc->average_select = ilog2(average_samples) - 2; + break; + default: + dev_err(&pdev->dev, + "touchscreen-average-samples (%u) must be 1, 4, 8, 16 or 32\n", + average_samples); + return -EINVAL; + } + + err = input_register_device(tsc->input); + if (err) { + dev_err(&pdev->dev, + "failed to register input device: %d\n", err); + return err; + } + + platform_set_drvdata(pdev, tsc); + return 0; +} + +static int __maybe_unused imx6ul_tsc_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct imx6ul_tsc *tsc = platform_get_drvdata(pdev); + struct input_dev *input_dev = tsc->input; + + mutex_lock(&input_dev->mutex); + + if (input_device_enabled(input_dev)) + imx6ul_tsc_stop(tsc); + + mutex_unlock(&input_dev->mutex); + + return 0; +} + +static int __maybe_unused imx6ul_tsc_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct imx6ul_tsc *tsc = platform_get_drvdata(pdev); + struct input_dev *input_dev = tsc->input; + int retval = 0; + + mutex_lock(&input_dev->mutex); + + if (input_device_enabled(input_dev)) + retval = imx6ul_tsc_start(tsc); + + mutex_unlock(&input_dev->mutex); + + return retval; +} + +static SIMPLE_DEV_PM_OPS(imx6ul_tsc_pm_ops, + imx6ul_tsc_suspend, imx6ul_tsc_resume); + +static const struct of_device_id imx6ul_tsc_match[] = { + { .compatible = "fsl,imx6ul-tsc", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, imx6ul_tsc_match); + +static struct platform_driver imx6ul_tsc_driver = { + .driver = { + .name = "imx6ul-tsc", + .of_match_table = imx6ul_tsc_match, + .pm = &imx6ul_tsc_pm_ops, + }, + .probe = imx6ul_tsc_probe, +}; +module_platform_driver(imx6ul_tsc_driver); + +MODULE_AUTHOR("Haibo Chen <haibo.chen@freescale.com>"); +MODULE_DESCRIPTION("Freescale i.MX6UL Touchscreen controller driver"); +MODULE_LICENSE("GPL v2"); |