/* * Atmel Touch Screen Driver * * Copyright (c) 2008 ATMEL * Copyright (c) 2008 Dan Liang * Copyright (c) 2008 TimeSys Corporation * Copyright (c) 2008 Justin Waters * * Based on touchscreen code from Atmel Corporation. * * 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/init.h> #include <linux/err.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/input.h> #include <linux/slab.h> #include <linux/interrupt.h> #include <linux/clk.h> #include <linux/platform_device.h> #include <linux/io.h> /* Register definitions based on AT91SAM9RL64 preliminary draft datasheet */ #define ATMEL_TSADCC_CR 0x00 /* Control register */ #define ATMEL_TSADCC_SWRST (1 << 0) /* Software Reset*/ #define ATMEL_TSADCC_START (1 << 1) /* Start conversion */ #define ATMEL_TSADCC_MR 0x04 /* Mode register */ #define ATMEL_TSADCC_TSAMOD (3 << 0) /* ADC mode */ #define ATMEL_TSADCC_TSAMOD_ADC_ONLY_MODE (0x0) /* ADC Mode */ #define ATMEL_TSADCC_TSAMOD_TS_ONLY_MODE (0x1) /* Touch Screen Only Mode */ #define ATMEL_TSADCC_LOWRES (1 << 4) /* Resolution selection */ #define ATMEL_TSADCC_SLEEP (1 << 5) /* Sleep mode */ #define ATMEL_TSADCC_PENDET (1 << 6) /* Pen Detect selection */ #define ATMEL_TSADCC_PRESCAL (0x3f << 8) /* Prescalar Rate Selection */ #define ATMEL_TSADCC_STARTUP (0x7f << 16) /* Start Up time */ #define ATMEL_TSADCC_SHTIM (0xf << 24) /* Sample & Hold time */ #define ATMEL_TSADCC_PENDBC (0xf << 28) /* Pen Detect debouncing time */ #define ATMEL_TSADCC_TRGR 0x08 /* Trigger register */ #define ATMEL_TSADCC_TRGMOD (7 << 0) /* Trigger mode */ #define ATMEL_TSADCC_TRGMOD_NONE (0 << 0) #define ATMEL_TSADCC_TRGMOD_EXT_RISING (1 << 0) #define ATMEL_TSADCC_TRGMOD_EXT_FALLING (2 << 0) #define ATMEL_TSADCC_TRGMOD_EXT_ANY (3 << 0) #define ATMEL_TSADCC_TRGMOD_PENDET (4 << 0) #define ATMEL_TSADCC_TRGMOD_PERIOD (5 << 0) #define ATMEL_TSADCC_TRGMOD_CONTINUOUS (6 << 0) #define ATMEL_TSADCC_TRGPER (0xffff << 16) /* Trigger period */ #define ATMEL_TSADCC_TSR 0x0C /* Touch Screen register */ #define ATMEL_TSADCC_TSFREQ (0xf << 0) /* TS Frequency in Interleaved mode */ #define ATMEL_TSADCC_TSSHTIM (0xf << 24) /* Sample & Hold time */ #define ATMEL_TSADCC_CHER 0x10 /* Channel Enable register */ #define ATMEL_TSADCC_CHDR 0x14 /* Channel Disable register */ #define ATMEL_TSADCC_CHSR 0x18 /* Channel Status register */ #define ATMEL_TSADCC_CH(n) (1 << (n)) /* Channel number */ #define ATMEL_TSADCC_SR 0x1C /* Status register */ #define ATMEL_TSADCC_EOC(n) (1 << ((n)+0)) /* End of conversion for channel N */ #define ATMEL_TSADCC_OVRE(n) (1 << ((n)+8)) /* Overrun error for channel N */ #define ATMEL_TSADCC_DRDY (1 << 16) /* Data Ready */ #define ATMEL_TSADCC_GOVRE (1 << 17) /* General Overrun Error */ #define ATMEL_TSADCC_ENDRX (1 << 18) /* End of RX Buffer */ #define ATMEL_TSADCC_RXBUFF (1 << 19) /* TX Buffer full */ #define ATMEL_TSADCC_PENCNT (1 << 20) /* Pen contact */ #define ATMEL_TSADCC_NOCNT (1 << 21) /* No contact */ #define ATMEL_TSADCC_LCDR 0x20 /* Last Converted Data register */ #define ATMEL_TSADCC_DATA (0x3ff << 0) /* Channel data */ #define ATMEL_TSADCC_IER 0x24 /* Interrupt Enable register */ #define ATMEL_TSADCC_IDR 0x28 /* Interrupt Disable register */ #define ATMEL_TSADCC_IMR 0x2C /* Interrupt Mask register */ #define ATMEL_TSADCC_CDR0 0x30 /* Channel Data 0 */ #define ATMEL_TSADCC_CDR1 0x34 /* Channel Data 1 */ #define ATMEL_TSADCC_CDR2 0x38 /* Channel Data 2 */ #define ATMEL_TSADCC_CDR3 0x3C /* Channel Data 3 */ #define ATMEL_TSADCC_CDR4 0x40 /* Channel Data 4 */ #define ATMEL_TSADCC_CDR5 0x44 /* Channel Data 5 */ #define ADC_CLOCK 1000000 struct atmel_tsadcc { struct input_dev *input; char phys[32]; struct clk *clk; int irq; unsigned int prev_absx; unsigned int prev_absy; unsigned char bufferedmeasure; }; static void __iomem *tsc_base; #define atmel_tsadcc_read(reg) __raw_readl(tsc_base + (reg)) #define atmel_tsadcc_write(reg, val) __raw_writel((val), tsc_base + (reg)) static irqreturn_t atmel_tsadcc_interrupt(int irq, void *dev) { struct atmel_tsadcc *ts_dev = (struct atmel_tsadcc *)dev; struct input_dev *input_dev = ts_dev->input; unsigned int status; unsigned int reg; status = atmel_tsadcc_read(ATMEL_TSADCC_SR); status &= atmel_tsadcc_read(ATMEL_TSADCC_IMR); if (status & ATMEL_TSADCC_NOCNT) { /* Contact lost */ reg = atmel_tsadcc_read(ATMEL_TSADCC_MR) | ATMEL_TSADCC_PENDBC; atmel_tsadcc_write(ATMEL_TSADCC_MR, reg); atmel_tsadcc_write(ATMEL_TSADCC_TRGR, ATMEL_TSADCC_TRGMOD_NONE); atmel_tsadcc_write(ATMEL_TSADCC_IDR, ATMEL_TSADCC_EOC(3) | ATMEL_TSADCC_NOCNT); atmel_tsadcc_write(ATMEL_TSADCC_IER, ATMEL_TSADCC_PENCNT); input_report_key(input_dev, BTN_TOUCH, 0); ts_dev->bufferedmeasure = 0; input_sync(input_dev); } else if (status & ATMEL_TSADCC_PENCNT) { /* Pen detected */ reg = atmel_tsadcc_read(ATMEL_TSADCC_MR); reg &= ~ATMEL_TSADCC_PENDBC; atmel_tsadcc_write(ATMEL_TSADCC_IDR, ATMEL_TSADCC_PENCNT); atmel_tsadcc_write(ATMEL_TSADCC_MR, reg); atmel_tsadcc_write(ATMEL_TSADCC_IER, ATMEL_TSADCC_EOC(3) | ATMEL_TSADCC_NOCNT); atmel_tsadcc_write(ATMEL_TSADCC_TRGR, ATMEL_TSADCC_TRGMOD_PERIOD | (0x0FFF << 16)); } else if (status & ATMEL_TSADCC_EOC(3)) { /* Conversion finished */ if (ts_dev->bufferedmeasure) { /* Last measurement is always discarded, since it can * be erroneous. * Always report previous measurement */ input_report_abs(input_dev, ABS_X, ts_dev->prev_absx); input_report_abs(input_dev, ABS_Y, ts_dev->prev_absy); input_report_key(input_dev, BTN_TOUCH, 1); input_sync(input_dev); } else ts_dev->bufferedmeasure = 1; /* Now make new measurement */ ts_dev->prev_absx = atmel_tsadcc_read(ATMEL_TSADCC_CDR3) << 10; ts_dev->prev_absx /= atmel_tsadcc_read(ATMEL_TSADCC_CDR2); ts_dev->prev_absy = atmel_tsadcc_read(ATMEL_TSADCC_CDR1) << 10; ts_dev->prev_absy /= atmel_tsadcc_read(ATMEL_TSADCC_CDR0); } return IRQ_HANDLED; } /* * The functions for inserting/removing us as a module. */ static int __devinit atmel_tsadcc_probe(struct platform_device *pdev) { struct atmel_tsadcc *ts_dev; struct input_dev *input_dev; struct resource *res; int err = 0; unsigned int prsc; unsigned int reg; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) { dev_err(&pdev->dev, "no mmio resource defined.\n"); return -ENXIO; } /* Allocate memory for device */ ts_dev = kzalloc(sizeof(struct atmel_tsadcc), GFP_KERNEL); if (!ts_dev) { dev_err(&pdev->dev, "failed to allocate memory.\n"); return -ENOMEM; } platform_set_drvdata(pdev, ts_dev); input_dev = input_allocate_device(); if (!input_dev) { dev_err(&pdev->dev, "failed to allocate input device.\n"); err = -EBUSY; goto err_free_mem; } ts_dev->irq = platform_get_irq(pdev, 0); if (ts_dev->irq < 0) { dev_err(&pdev->dev, "no irq ID is designated.\n"); err = -ENODEV; goto err_free_dev; } if (!request_mem_region(res->start, res->end - res->start + 1, "atmel tsadcc regs")) { dev_err(&pdev->dev, "resources is unavailable.\n"); err = -EBUSY; goto err_free_dev; } tsc_base = ioremap(res->start, res->end - res->start + 1); if (!tsc_base) { dev_err(&pdev->dev, "failed to map registers.\n"); err = -ENOMEM; goto err_release_mem; } err = request_irq(ts_dev->irq, atmel_tsadcc_interrupt, IRQF_DISABLED, pdev->dev.driver->name, ts_dev); if (err) { dev_err(&pdev->dev, "failed to allocate irq.\n"); goto err_unmap_regs; } ts_dev->clk = clk_get(&pdev->dev, "tsc_clk"); if (IS_ERR(ts_dev->clk)) { dev_err(&pdev->dev, "failed to get ts_clk\n"); err = PTR_ERR(ts_dev->clk); goto err_free_irq; } ts_dev->input = input_dev; ts_dev->bufferedmeasure = 0; snprintf(ts_dev->phys, sizeof(ts_dev->phys), "%s/input0", dev_name(&pdev->dev)); input_dev->name = "atmel touch screen controller"; input_dev->phys = ts_dev->phys; input_dev->dev.parent = &pdev->dev; input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); input_set_abs_params(input_dev, ABS_X, 0, 0x3FF, 0, 0); input_set_abs_params(input_dev, ABS_Y, 0, 0x3FF, 0, 0); /* clk_enable() always returns 0, no need to check it */ clk_enable(ts_dev->clk); prsc = clk_get_rate(ts_dev->clk); dev_info(&pdev->dev, "Master clock is set at: %d Hz\n", prsc); prsc = prsc / ADC_CLOCK / 2 - 1; reg = ATMEL_TSADCC_TSAMOD_TS_ONLY_MODE | ((0x00 << 5) & ATMEL_TSADCC_SLEEP) | /* Normal Mode */ ((0x01 << 6) & ATMEL_TSADCC_PENDET) | /* Enable Pen Detect */ ((prsc << 8) & ATMEL_TSADCC_PRESCAL) | /* PRESCAL */ ((0x13 << 16) & ATMEL_TSADCC_STARTUP) | /* STARTUP */ ((0x0F << 28) & ATMEL_TSADCC_PENDBC); /* PENDBC */ atmel_tsadcc_write(ATMEL_TSADCC_CR, ATMEL_TSADCC_SWRST); atmel_tsadcc_write(ATMEL_TSADCC_MR, reg); atmel_tsadcc_write(ATMEL_TSADCC_TRGR, ATMEL_TSADCC_TRGMOD_NONE); atmel_tsadcc_write(ATMEL_TSADCC_TSR, (0x3 << 24) & ATMEL_TSADCC_TSSHTIM); atmel_tsadcc_read(ATMEL_TSADCC_SR); atmel_tsadcc_write(ATMEL_TSADCC_IER, ATMEL_TSADCC_PENCNT); /* All went ok, so register to the input system */ err = input_register_device(input_dev); if (err) goto err_fail; return 0; err_fail: clk_disable(ts_dev->clk); clk_put(ts_dev->clk); err_free_irq: free_irq(ts_dev->irq, ts_dev); err_unmap_regs: iounmap(tsc_base); err_release_mem: release_mem_region(res->start, res->end - res->start + 1); err_free_dev: input_free_device(ts_dev->input); err_free_mem: kfree(ts_dev); return err; } static int __devexit atmel_tsadcc_remove(struct platform_device *pdev) { struct atmel_tsadcc *ts_dev = dev_get_drvdata(&pdev->dev); struct resource *res; free_irq(ts_dev->irq, ts_dev); input_unregister_device(ts_dev->input); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); iounmap(tsc_base); release_mem_region(res->start, res->end - res->start + 1); clk_disable(ts_dev->clk); clk_put(ts_dev->clk); kfree(ts_dev); return 0; } static struct platform_driver atmel_tsadcc_driver = { .probe = atmel_tsadcc_probe, .remove = __devexit_p(atmel_tsadcc_remove), .driver = { .name = "atmel_tsadcc", }, }; static int __init atmel_tsadcc_init(void) { return platform_driver_register(&atmel_tsadcc_driver); } static void __exit atmel_tsadcc_exit(void) { platform_driver_unregister(&atmel_tsadcc_driver); } module_init(atmel_tsadcc_init); module_exit(atmel_tsadcc_exit); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Atmel TouchScreen Driver"); MODULE_AUTHOR("Dan Liang <dan.liang@atmel.com>");