![Fabio Estevam](/assets/img/avatar_default.png)
We should better write "Touchscreen". Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
534 lines
13 KiB
C
534 lines
13 KiB
C
/*
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* Freescale i.MX6UL touchscreen controller driver
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*
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* Copyright (C) 2015 Freescale Semiconductor, Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/gpio/consumer.h>
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#include <linux/input.h>
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#include <linux/slab.h>
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#include <linux/completion.h>
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#include <linux/delay.h>
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#include <linux/of.h>
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#include <linux/interrupt.h>
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#include <linux/platform_device.h>
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#include <linux/clk.h>
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#include <linux/io.h>
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/* ADC configuration registers field define */
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#define ADC_AIEN (0x1 << 7)
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#define ADC_CONV_DISABLE 0x1F
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#define ADC_CAL (0x1 << 7)
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#define ADC_CALF 0x2
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#define ADC_12BIT_MODE (0x2 << 2)
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#define ADC_IPG_CLK 0x00
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#define ADC_CLK_DIV_8 (0x03 << 5)
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#define ADC_SHORT_SAMPLE_MODE (0x0 << 4)
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#define ADC_HARDWARE_TRIGGER (0x1 << 13)
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#define SELECT_CHANNEL_4 0x04
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#define SELECT_CHANNEL_1 0x01
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#define DISABLE_CONVERSION_INT (0x0 << 7)
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/* ADC registers */
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#define REG_ADC_HC0 0x00
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#define REG_ADC_HC1 0x04
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#define REG_ADC_HC2 0x08
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#define REG_ADC_HC3 0x0C
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#define REG_ADC_HC4 0x10
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#define REG_ADC_HS 0x14
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#define REG_ADC_R0 0x18
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#define REG_ADC_CFG 0x2C
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#define REG_ADC_GC 0x30
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#define REG_ADC_GS 0x34
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#define ADC_TIMEOUT msecs_to_jiffies(100)
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/* TSC registers */
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#define REG_TSC_BASIC_SETING 0x00
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#define REG_TSC_PRE_CHARGE_TIME 0x10
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#define REG_TSC_FLOW_CONTROL 0x20
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#define REG_TSC_MEASURE_VALUE 0x30
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#define REG_TSC_INT_EN 0x40
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#define REG_TSC_INT_SIG_EN 0x50
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#define REG_TSC_INT_STATUS 0x60
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#define REG_TSC_DEBUG_MODE 0x70
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#define REG_TSC_DEBUG_MODE2 0x80
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/* TSC configuration registers field define */
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#define DETECT_4_WIRE_MODE (0x0 << 4)
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#define AUTO_MEASURE 0x1
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#define MEASURE_SIGNAL 0x1
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#define DETECT_SIGNAL (0x1 << 4)
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#define VALID_SIGNAL (0x1 << 8)
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#define MEASURE_INT_EN 0x1
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#define MEASURE_SIG_EN 0x1
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#define VALID_SIG_EN (0x1 << 8)
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#define DE_GLITCH_2 (0x2 << 29)
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#define START_SENSE (0x1 << 12)
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#define TSC_DISABLE (0x1 << 16)
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#define DETECT_MODE 0x2
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struct imx6ul_tsc {
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struct device *dev;
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struct input_dev *input;
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void __iomem *tsc_regs;
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void __iomem *adc_regs;
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struct clk *tsc_clk;
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struct clk *adc_clk;
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struct gpio_desc *xnur_gpio;
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int measure_delay_time;
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int pre_charge_time;
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struct completion completion;
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};
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/*
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* TSC module need ADC to get the measure value. So
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* before config TSC, we should initialize ADC module.
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*/
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static int imx6ul_adc_init(struct imx6ul_tsc *tsc)
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{
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int adc_hc = 0;
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int adc_gc;
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int adc_gs;
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int adc_cfg;
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int timeout;
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reinit_completion(&tsc->completion);
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adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG);
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adc_cfg |= ADC_12BIT_MODE | ADC_IPG_CLK;
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adc_cfg |= ADC_CLK_DIV_8 | ADC_SHORT_SAMPLE_MODE;
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adc_cfg &= ~ADC_HARDWARE_TRIGGER;
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writel(adc_cfg, tsc->adc_regs + REG_ADC_CFG);
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/* enable calibration interrupt */
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adc_hc |= ADC_AIEN;
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adc_hc |= ADC_CONV_DISABLE;
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writel(adc_hc, tsc->adc_regs + REG_ADC_HC0);
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/* start ADC calibration */
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adc_gc = readl(tsc->adc_regs + REG_ADC_GC);
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adc_gc |= ADC_CAL;
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writel(adc_gc, tsc->adc_regs + REG_ADC_GC);
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timeout = wait_for_completion_timeout
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(&tsc->completion, ADC_TIMEOUT);
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if (timeout == 0) {
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dev_err(tsc->dev, "Timeout for adc calibration\n");
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return -ETIMEDOUT;
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}
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adc_gs = readl(tsc->adc_regs + REG_ADC_GS);
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if (adc_gs & ADC_CALF) {
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dev_err(tsc->dev, "ADC calibration failed\n");
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return -EINVAL;
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}
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/* TSC need the ADC work in hardware trigger */
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adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG);
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adc_cfg |= ADC_HARDWARE_TRIGGER;
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writel(adc_cfg, tsc->adc_regs + REG_ADC_CFG);
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return 0;
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}
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/*
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* This is a TSC workaround. Currently TSC misconnect two
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* ADC channels, this function remap channel configure for
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* hardware trigger.
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*/
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static void imx6ul_tsc_channel_config(struct imx6ul_tsc *tsc)
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{
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int adc_hc0, adc_hc1, adc_hc2, adc_hc3, adc_hc4;
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adc_hc0 = DISABLE_CONVERSION_INT;
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writel(adc_hc0, tsc->adc_regs + REG_ADC_HC0);
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adc_hc1 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_4;
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writel(adc_hc1, tsc->adc_regs + REG_ADC_HC1);
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adc_hc2 = DISABLE_CONVERSION_INT;
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writel(adc_hc2, tsc->adc_regs + REG_ADC_HC2);
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adc_hc3 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_1;
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writel(adc_hc3, tsc->adc_regs + REG_ADC_HC3);
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adc_hc4 = DISABLE_CONVERSION_INT;
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writel(adc_hc4, tsc->adc_regs + REG_ADC_HC4);
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}
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/*
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* TSC setting, confige the pre-charge time and measure delay time.
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* different touch screen may need different pre-charge time and
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* measure delay time.
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*/
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static void imx6ul_tsc_set(struct imx6ul_tsc *tsc)
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{
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int basic_setting = 0;
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int start;
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basic_setting |= tsc->measure_delay_time << 8;
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basic_setting |= DETECT_4_WIRE_MODE | AUTO_MEASURE;
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writel(basic_setting, tsc->tsc_regs + REG_TSC_BASIC_SETING);
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writel(DE_GLITCH_2, tsc->tsc_regs + REG_TSC_DEBUG_MODE2);
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writel(tsc->pre_charge_time, tsc->tsc_regs + REG_TSC_PRE_CHARGE_TIME);
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writel(MEASURE_INT_EN, tsc->tsc_regs + REG_TSC_INT_EN);
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writel(MEASURE_SIG_EN | VALID_SIG_EN,
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tsc->tsc_regs + REG_TSC_INT_SIG_EN);
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/* start sense detection */
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start = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
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start |= START_SENSE;
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start &= ~TSC_DISABLE;
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writel(start, tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
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}
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static int imx6ul_tsc_init(struct imx6ul_tsc *tsc)
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{
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int err;
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err = imx6ul_adc_init(tsc);
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if (err)
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return err;
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imx6ul_tsc_channel_config(tsc);
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imx6ul_tsc_set(tsc);
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return 0;
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}
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static void imx6ul_tsc_disable(struct imx6ul_tsc *tsc)
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{
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int tsc_flow;
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int adc_cfg;
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/* TSC controller enters to idle status */
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tsc_flow = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
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tsc_flow |= TSC_DISABLE;
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writel(tsc_flow, tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
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/* ADC controller enters to stop mode */
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adc_cfg = readl(tsc->adc_regs + REG_ADC_HC0);
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adc_cfg |= ADC_CONV_DISABLE;
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writel(adc_cfg, tsc->adc_regs + REG_ADC_HC0);
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}
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/* Delay some time (max 2ms), wait the pre-charge done. */
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static bool tsc_wait_detect_mode(struct imx6ul_tsc *tsc)
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{
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unsigned long timeout = jiffies + msecs_to_jiffies(2);
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int state_machine;
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int debug_mode2;
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do {
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if (time_after(jiffies, timeout))
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return false;
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usleep_range(200, 400);
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debug_mode2 = readl(tsc->tsc_regs + REG_TSC_DEBUG_MODE2);
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state_machine = (debug_mode2 >> 20) & 0x7;
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} while (state_machine != DETECT_MODE);
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usleep_range(200, 400);
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return true;
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}
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static irqreturn_t tsc_irq_fn(int irq, void *dev_id)
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{
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struct imx6ul_tsc *tsc = dev_id;
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int status;
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int value;
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int x, y;
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int start;
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status = readl(tsc->tsc_regs + REG_TSC_INT_STATUS);
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/* write 1 to clear the bit measure-signal */
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writel(MEASURE_SIGNAL | DETECT_SIGNAL,
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tsc->tsc_regs + REG_TSC_INT_STATUS);
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/* It's a HW self-clean bit. Set this bit and start sense detection */
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start = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
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start |= START_SENSE;
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writel(start, tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
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if (status & MEASURE_SIGNAL) {
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value = readl(tsc->tsc_regs + REG_TSC_MEASURE_VALUE);
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x = (value >> 16) & 0x0fff;
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y = value & 0x0fff;
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/*
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* In detect mode, we can get the xnur gpio value,
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* otherwise assume contact is stiull active.
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*/
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if (!tsc_wait_detect_mode(tsc) ||
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gpiod_get_value_cansleep(tsc->xnur_gpio)) {
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input_report_key(tsc->input, BTN_TOUCH, 1);
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input_report_abs(tsc->input, ABS_X, x);
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input_report_abs(tsc->input, ABS_Y, y);
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} else {
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input_report_key(tsc->input, BTN_TOUCH, 0);
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}
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input_sync(tsc->input);
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}
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return IRQ_HANDLED;
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}
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static irqreturn_t adc_irq_fn(int irq, void *dev_id)
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{
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struct imx6ul_tsc *tsc = dev_id;
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int coco;
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int value;
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coco = readl(tsc->adc_regs + REG_ADC_HS);
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if (coco & 0x01) {
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value = readl(tsc->adc_regs + REG_ADC_R0);
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complete(&tsc->completion);
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}
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return IRQ_HANDLED;
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}
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static int imx6ul_tsc_open(struct input_dev *input_dev)
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{
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struct imx6ul_tsc *tsc = input_get_drvdata(input_dev);
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int err;
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err = clk_prepare_enable(tsc->adc_clk);
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if (err) {
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dev_err(tsc->dev,
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"Could not prepare or enable the adc clock: %d\n",
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err);
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return err;
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}
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err = clk_prepare_enable(tsc->tsc_clk);
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if (err) {
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dev_err(tsc->dev,
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"Could not prepare or enable the tsc clock: %d\n",
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err);
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clk_disable_unprepare(tsc->adc_clk);
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return err;
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}
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return imx6ul_tsc_init(tsc);
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}
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static void imx6ul_tsc_close(struct input_dev *input_dev)
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{
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struct imx6ul_tsc *tsc = input_get_drvdata(input_dev);
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imx6ul_tsc_disable(tsc);
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clk_disable_unprepare(tsc->tsc_clk);
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clk_disable_unprepare(tsc->adc_clk);
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}
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static int imx6ul_tsc_probe(struct platform_device *pdev)
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{
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struct device_node *np = pdev->dev.of_node;
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struct imx6ul_tsc *tsc;
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struct input_dev *input_dev;
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struct resource *tsc_mem;
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struct resource *adc_mem;
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int err;
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int tsc_irq;
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int adc_irq;
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tsc = devm_kzalloc(&pdev->dev, sizeof(*tsc), GFP_KERNEL);
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if (!tsc)
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return -ENOMEM;
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input_dev = devm_input_allocate_device(&pdev->dev);
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if (!input_dev)
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return -ENOMEM;
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input_dev->name = "iMX6UL Touchscreen Controller";
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input_dev->id.bustype = BUS_HOST;
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input_dev->open = imx6ul_tsc_open;
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input_dev->close = imx6ul_tsc_close;
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input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
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input_set_abs_params(input_dev, ABS_X, 0, 0xFFF, 0, 0);
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input_set_abs_params(input_dev, ABS_Y, 0, 0xFFF, 0, 0);
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input_set_drvdata(input_dev, tsc);
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tsc->dev = &pdev->dev;
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tsc->input = input_dev;
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init_completion(&tsc->completion);
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tsc->xnur_gpio = devm_gpiod_get(&pdev->dev, "xnur", GPIOD_IN);
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if (IS_ERR(tsc->xnur_gpio)) {
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err = PTR_ERR(tsc->xnur_gpio);
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dev_err(&pdev->dev,
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"failed to request GPIO tsc_X- (xnur): %d\n", err);
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return err;
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}
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tsc_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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tsc->tsc_regs = devm_ioremap_resource(&pdev->dev, tsc_mem);
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if (IS_ERR(tsc->tsc_regs)) {
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err = PTR_ERR(tsc->tsc_regs);
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dev_err(&pdev->dev, "failed to remap tsc memory: %d\n", err);
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return err;
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}
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adc_mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
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tsc->adc_regs = devm_ioremap_resource(&pdev->dev, adc_mem);
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if (IS_ERR(tsc->adc_regs)) {
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err = PTR_ERR(tsc->adc_regs);
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dev_err(&pdev->dev, "failed to remap adc memory: %d\n", err);
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return err;
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}
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tsc->tsc_clk = devm_clk_get(&pdev->dev, "tsc");
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if (IS_ERR(tsc->tsc_clk)) {
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err = PTR_ERR(tsc->tsc_clk);
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dev_err(&pdev->dev, "failed getting tsc clock: %d\n", err);
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return err;
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}
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tsc->adc_clk = devm_clk_get(&pdev->dev, "adc");
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if (IS_ERR(tsc->adc_clk)) {
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err = PTR_ERR(tsc->adc_clk);
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dev_err(&pdev->dev, "failed getting adc clock: %d\n", err);
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return err;
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}
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tsc_irq = platform_get_irq(pdev, 0);
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if (tsc_irq < 0) {
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dev_err(&pdev->dev, "no tsc irq resource?\n");
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return tsc_irq;
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}
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adc_irq = platform_get_irq(pdev, 1);
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if (adc_irq < 0) {
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dev_err(&pdev->dev, "no adc irq resource?\n");
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return adc_irq;
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}
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err = devm_request_threaded_irq(tsc->dev, tsc_irq,
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NULL, tsc_irq_fn, IRQF_ONESHOT,
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dev_name(&pdev->dev), tsc);
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if (err) {
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dev_err(&pdev->dev,
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"failed requesting tsc irq %d: %d\n",
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tsc_irq, err);
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return err;
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}
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err = devm_request_irq(tsc->dev, adc_irq, adc_irq_fn, 0,
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dev_name(&pdev->dev), tsc);
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if (err) {
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dev_err(&pdev->dev,
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"failed requesting adc irq %d: %d\n",
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adc_irq, err);
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return err;
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}
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err = of_property_read_u32(np, "measure-delay-time",
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&tsc->measure_delay_time);
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if (err)
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tsc->measure_delay_time = 0xffff;
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err = of_property_read_u32(np, "pre-charge-time",
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&tsc->pre_charge_time);
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if (err)
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tsc->pre_charge_time = 0xfff;
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err = input_register_device(tsc->input);
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if (err) {
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dev_err(&pdev->dev,
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"failed to register input device: %d\n", err);
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return err;
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}
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platform_set_drvdata(pdev, tsc);
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return 0;
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}
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static int __maybe_unused imx6ul_tsc_suspend(struct device *dev)
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{
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struct platform_device *pdev = to_platform_device(dev);
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struct imx6ul_tsc *tsc = platform_get_drvdata(pdev);
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struct input_dev *input_dev = tsc->input;
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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");
|