--- /dev/null
+/*
+ * Freescale i.MX6UL touchscreen controller driver
+ *
+ * Copyright (C) 2015 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#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>
+
+/* ADC configuration registers field define */
+#define ADC_AIEN (0x1 << 7)
+#define ADC_CONV_DISABLE 0x1F
+#define ADC_CAL (0x1 << 7)
+#define ADC_CALF 0x2
+#define ADC_12BIT_MODE (0x2 << 2)
+#define ADC_IPG_CLK 0x00
+#define ADC_CLK_DIV_8 (0x03 << 5)
+#define ADC_SHORT_SAMPLE_MODE (0x0 << 4)
+#define ADC_HARDWARE_TRIGGER (0x1 << 13)
+#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;
+
+ int measure_delay_time;
+ int pre_charge_time;
+
+ 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)
+{
+ int adc_hc = 0;
+ int adc_gc;
+ int adc_gs;
+ int adc_cfg;
+ int timeout;
+
+ reinit_completion(&tsc->completion);
+
+ adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG);
+ adc_cfg |= ADC_12BIT_MODE | ADC_IPG_CLK;
+ adc_cfg |= ADC_CLK_DIV_8 | ADC_SHORT_SAMPLE_MODE;
+ 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;
+ 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)
+{
+ int 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)
+{
+ int basic_setting = 0;
+ int 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)
+{
+ int tsc_flow;
+ int 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);
+ int state_machine;
+ int 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;
+ int status;
+ int value;
+ int x, y;
+ int 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;
+ int coco;
+ int value;
+
+ coco = readl(tsc->adc_regs + REG_ADC_HS);
+ if (coco & 0x01) {
+ value = readl(tsc->adc_regs + REG_ADC_R0);
+ complete(&tsc->completion);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int imx6ul_tsc_open(struct input_dev *input_dev)
+{
+ struct imx6ul_tsc *tsc = input_get_drvdata(input_dev);
+ 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);
+ clk_disable_unprepare(tsc->adc_clk);
+ return err;
+ }
+
+ return imx6ul_tsc_init(tsc);
+}
+
+static void imx6ul_tsc_close(struct input_dev *input_dev)
+{
+ struct imx6ul_tsc *tsc = input_get_drvdata(input_dev);
+
+ imx6ul_tsc_disable(tsc);
+
+ clk_disable_unprepare(tsc->tsc_clk);
+ clk_disable_unprepare(tsc->adc_clk);
+}
+
+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;
+ struct resource *tsc_mem;
+ struct resource *adc_mem;
+ int err;
+ int tsc_irq;
+ int adc_irq;
+
+ 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_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ tsc->tsc_regs = devm_ioremap_resource(&pdev->dev, tsc_mem);
+ 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;
+ }
+
+ adc_mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+ tsc->adc_regs = devm_ioremap_resource(&pdev->dev, adc_mem);
+ 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) {
+ dev_err(&pdev->dev, "no tsc irq resource?\n");
+ return tsc_irq;
+ }
+
+ adc_irq = platform_get_irq(pdev, 1);
+ if (adc_irq < 0) {
+ dev_err(&pdev->dev, "no adc irq resource?\n");
+ 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 = 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_dev->users) {
+ imx6ul_tsc_disable(tsc);
+
+ clk_disable_unprepare(tsc->tsc_clk);
+ clk_disable_unprepare(tsc->adc_clk);
+ }
+
+ 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_dev->users) {
+ retval = clk_prepare_enable(tsc->adc_clk);
+ if (retval)
+ goto out;
+
+ retval = clk_prepare_enable(tsc->tsc_clk);
+ if (retval) {
+ clk_disable_unprepare(tsc->adc_clk);
+ goto out;
+ }
+
+ retval = imx6ul_tsc_init(tsc);
+ }
+
+out:
+ 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");
Code Review / kvmfornfv.git / blobdiff