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Release 4.11 drivers/input/touchscreen/imx6ul_tsc.c

/*
 * 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>
#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; }

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/* * 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); }

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/* * 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); }

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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; }

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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); }

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/* 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; }

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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; }

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static irqreturn_t adc_irq_fn(int irq, void *dev_id) { struct imx6ul_tsc *tsc = dev_id; u32 coco; u32 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; }

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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); }

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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); }

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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; 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_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 = 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; }

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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; }

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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; }

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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");

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