/* * LPC32xx built-in touchscreen driver * * Copyright (C) 2010 NXP Semiconductors * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include <linux/platform_device.h> #include <linux/input.h> #include <linux/interrupt.h> #include <linux/module.h> #include <linux/clk.h> #include <linux/io.h> #include <linux/slab.h> #include <linux/of.h> /* * Touchscreen controller register offsets */ #define LPC32XX_TSC_STAT 0x00 #define LPC32XX_TSC_SEL 0x04 #define LPC32XX_TSC_CON 0x08 #define LPC32XX_TSC_FIFO 0x0C #define LPC32XX_TSC_DTR 0x10 #define LPC32XX_TSC_RTR 0x14 #define LPC32XX_TSC_UTR 0x18 #define LPC32XX_TSC_TTR 0x1C #define LPC32XX_TSC_DXP 0x20 #define LPC32XX_TSC_MIN_X 0x24 #define LPC32XX_TSC_MAX_X 0x28 #define LPC32XX_TSC_MIN_Y 0x2C #define LPC32XX_TSC_MAX_Y 0x30 #define LPC32XX_TSC_AUX_UTR 0x34 #define LPC32XX_TSC_AUX_MIN 0x38 #define LPC32XX_TSC_AUX_MAX 0x3C #define LPC32XX_TSC_STAT_FIFO_OVRRN (1 << 8) #define LPC32XX_TSC_STAT_FIFO_EMPTY (1 << 7) #define LPC32XX_TSC_SEL_DEFVAL 0x0284 #define LPC32XX_TSC_ADCCON_IRQ_TO_FIFO_4 (0x1 << 11) #define LPC32XX_TSC_ADCCON_X_SAMPLE_SIZE(s) ((10 - (s)) << 7) #define LPC32XX_TSC_ADCCON_Y_SAMPLE_SIZE(s) ((10 - (s)) << 4) #define LPC32XX_TSC_ADCCON_POWER_UP (1 << 2) #define LPC32XX_TSC_ADCCON_AUTO_EN (1 << 0) #define LPC32XX_TSC_FIFO_TS_P_LEVEL (1 << 31) #define LPC32XX_TSC_FIFO_NORMALIZE_X_VAL(x) (((x) & 0x03FF0000) >> 16) #define LPC32XX_TSC_FIFO_NORMALIZE_Y_VAL(y) ((y) & 0x000003FF) #define LPC32XX_TSC_ADCDAT_VALUE_MASK 0x000003FF #define LPC32XX_TSC_MIN_XY_VAL 0x0 #define LPC32XX_TSC_MAX_XY_VAL 0x3FF #define MOD_NAME "ts-lpc32xx" #define tsc_readl(dev, reg) \ __raw_readl((dev)->tsc_base + (reg)) #define tsc_writel(dev, reg, val) \ __raw_writel((val), (dev)->tsc_base + (reg)) struct lpc32xx_tsc { struct input_dev *dev; void __iomem *tsc_base; int irq; struct clk *clk; }; static void lpc32xx_fifo_clear(struct lpc32xx_tsc *tsc) { while (!(tsc_readl(tsc, LPC32XX_TSC_STAT) & LPC32XX_TSC_STAT_FIFO_EMPTY)) tsc_readl(tsc, LPC32XX_TSC_FIFO); } static irqreturn_t lpc32xx_ts_interrupt(int irq, void *dev_id) { u32 tmp, rv[4], xs[4], ys[4]; int idx; struct lpc32xx_tsc *tsc = dev_id; struct input_dev *input = tsc->dev; tmp = tsc_readl(tsc, LPC32XX_TSC_STAT); if (tmp & LPC32XX_TSC_STAT_FIFO_OVRRN) { /* FIFO overflow - throw away samples */ lpc32xx_fifo_clear(tsc); return IRQ_HANDLED; } /* * Gather and normalize 4 samples. Pen-up events may have less * than 4 samples, but its ok to pop 4 and let the last sample * pen status check drop the samples. */ idx = 0; while (idx < 4 && !(tsc_readl(tsc, LPC32XX_TSC_STAT) & LPC32XX_TSC_STAT_FIFO_EMPTY)) { tmp = tsc_readl(tsc, LPC32XX_TSC_FIFO); xs[idx] = LPC32XX_TSC_ADCDAT_VALUE_MASK - LPC32XX_TSC_FIFO_NORMALIZE_X_VAL(tmp); ys[idx] = LPC32XX_TSC_ADCDAT_VALUE_MASK - LPC32XX_TSC_FIFO_NORMALIZE_Y_VAL(tmp); rv[idx] = tmp; idx++; } /* Data is only valid if pen is still down in last sample */ if (!(rv[3] & LPC32XX_TSC_FIFO_TS_P_LEVEL) && idx == 4) { /* Use average of 2nd and 3rd sample for position */ input_report_abs(input, ABS_X, (xs[1] + xs[2]) / 2); input_report_abs(input, ABS_Y, (ys[1] + ys[2]) / 2); input_report_key(input, BTN_TOUCH, 1); } else { input_report_key(input, BTN_TOUCH, 0); } input_sync(input); return IRQ_HANDLED; } static void lpc32xx_stop_tsc(struct lpc32xx_tsc *tsc) { /* Disable auto mode */ tsc_writel(tsc, LPC32XX_TSC_CON, tsc_readl(tsc, LPC32XX_TSC_CON) & ~LPC32XX_TSC_ADCCON_AUTO_EN); clk_disable_unprepare(tsc->clk); } static int lpc32xx_setup_tsc(struct lpc32xx_tsc *tsc) { u32 tmp; int err; err = clk_prepare_enable(tsc->clk); if (err) return err; tmp = tsc_readl(tsc, LPC32XX_TSC_CON) & ~LPC32XX_TSC_ADCCON_POWER_UP; /* Set the TSC FIFO depth to 4 samples @ 10-bits per sample (max) */ tmp = LPC32XX_TSC_ADCCON_IRQ_TO_FIFO_4 | LPC32XX_TSC_ADCCON_X_SAMPLE_SIZE(10) | LPC32XX_TSC_ADCCON_Y_SAMPLE_SIZE(10); tsc_writel(tsc, LPC32XX_TSC_CON, tmp); /* These values are all preset */ tsc_writel(tsc, LPC32XX_TSC_SEL, LPC32XX_TSC_SEL_DEFVAL); tsc_writel(tsc, LPC32XX_TSC_MIN_X, LPC32XX_TSC_MIN_XY_VAL); tsc_writel(tsc, LPC32XX_TSC_MAX_X, LPC32XX_TSC_MAX_XY_VAL); tsc_writel(tsc, LPC32XX_TSC_MIN_Y, LPC32XX_TSC_MIN_XY_VAL); tsc_writel(tsc, LPC32XX_TSC_MAX_Y, LPC32XX_TSC_MAX_XY_VAL); /* Aux support is not used */ tsc_writel(tsc, LPC32XX_TSC_AUX_UTR, 0); tsc_writel(tsc, LPC32XX_TSC_AUX_MIN, 0); tsc_writel(tsc, LPC32XX_TSC_AUX_MAX, 0); /* * Set sample rate to about 240Hz per X/Y pair. A single measurement * consists of 4 pairs which gives about a 60Hz sample rate based on * a stable 32768Hz clock source. Values are in clocks. * Rate is (32768 / (RTR + XCONV + RTR + YCONV + DXP + TTR + UTR) / 4 */ tsc_writel(tsc, LPC32XX_TSC_RTR, 0x2); tsc_writel(tsc, LPC32XX_TSC_DTR, 0x2); tsc_writel(tsc, LPC32XX_TSC_TTR, 0x10); tsc_writel(tsc, LPC32XX_TSC_DXP, 0x4); tsc_writel(tsc, LPC32XX_TSC_UTR, 88); lpc32xx_fifo_clear(tsc); /* Enable automatic ts event capture */ tsc_writel(tsc, LPC32XX_TSC_CON, tmp | LPC32XX_TSC_ADCCON_AUTO_EN); return 0; } static int lpc32xx_ts_open(struct input_dev *dev) { struct lpc32xx_tsc *tsc = input_get_drvdata(dev); return lpc32xx_setup_tsc(tsc); } static void lpc32xx_ts_close(struct input_dev *dev) { struct lpc32xx_tsc *tsc = input_get_drvdata(dev); lpc32xx_stop_tsc(tsc); } static int lpc32xx_ts_probe(struct platform_device *pdev) { struct lpc32xx_tsc *tsc; struct input_dev *input; struct resource *res; resource_size_t size; int irq; int error; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) { dev_err(&pdev->dev, "Can't get memory resource\n"); return -ENOENT; } irq = platform_get_irq(pdev, 0); if (irq < 0) { dev_err(&pdev->dev, "Can't get interrupt resource\n"); return irq; } tsc = kzalloc(sizeof(*tsc), GFP_KERNEL); input = input_allocate_device(); if (!tsc || !input) { dev_err(&pdev->dev, "failed allocating memory\n"); error = -ENOMEM; goto err_free_mem; } tsc->dev = input; tsc->irq = irq; size = resource_size(res); if (!request_mem_region(res->start, size, pdev->name)) { dev_err(&pdev->dev, "TSC registers are not free\n"); error = -EBUSY; goto err_free_mem; } tsc->tsc_base = ioremap(res->start, size); if (!tsc->tsc_base) { dev_err(&pdev->dev, "Can't map memory\n"); error = -ENOMEM; goto err_release_mem; } tsc->clk = clk_get(&pdev->dev, NULL); if (IS_ERR(tsc->clk)) { dev_err(&pdev->dev, "failed getting clock\n"); error = PTR_ERR(tsc->clk); goto err_unmap; } input->name = MOD_NAME; input->phys = "lpc32xx/input0"; input->id.bustype = BUS_HOST; input->id.vendor = 0x0001; input->id.product = 0x0002; input->id.version = 0x0100; input->dev.parent = &pdev->dev; input->open = lpc32xx_ts_open; input->close = lpc32xx_ts_close; input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); input_set_abs_params(input, ABS_X, LPC32XX_TSC_MIN_XY_VAL, LPC32XX_TSC_MAX_XY_VAL, 0, 0); input_set_abs_params(input, ABS_Y, LPC32XX_TSC_MIN_XY_VAL, LPC32XX_TSC_MAX_XY_VAL, 0, 0); input_set_drvdata(input, tsc); error = request_irq(tsc->irq, lpc32xx_ts_interrupt, 0, pdev->name, tsc); if (error) { dev_err(&pdev->dev, "failed requesting interrupt\n"); goto err_put_clock; } error = input_register_device(input); if (error) { dev_err(&pdev->dev, "failed registering input device\n"); goto err_free_irq; } platform_set_drvdata(pdev, tsc); device_init_wakeup(&pdev->dev, 1); return 0; err_free_irq: free_irq(tsc->irq, tsc); err_put_clock: clk_put(tsc->clk); err_unmap: iounmap(tsc->tsc_base); err_release_mem: release_mem_region(res->start, size); err_free_mem: input_free_device(input); kfree(tsc); return error; } static int lpc32xx_ts_remove(struct platform_device *pdev) { struct lpc32xx_tsc *tsc = platform_get_drvdata(pdev); struct resource *res; free_irq(tsc->irq, tsc); input_unregister_device(tsc->dev); clk_put(tsc->clk); iounmap(tsc->tsc_base); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); release_mem_region(res->start, resource_size(res)); kfree(tsc); return 0; } #ifdef CONFIG_PM static int lpc32xx_ts_suspend(struct device *dev) { struct lpc32xx_tsc *tsc = dev_get_drvdata(dev); struct input_dev *input = tsc->dev; /* * Suspend and resume can be called when the device hasn't been * enabled. If there are no users that have the device open, then * avoid calling the TSC stop and start functions as the TSC * isn't yet clocked. */ mutex_lock(&input->mutex); if (input->users) { if (device_may_wakeup(dev)) enable_irq_wake(tsc->irq); else lpc32xx_stop_tsc(tsc); } mutex_unlock(&input->mutex); return 0; } static int lpc32xx_ts_resume(struct device *dev) { struct lpc32xx_tsc *tsc = dev_get_drvdata(dev); struct input_dev *input = tsc->dev; mutex_lock(&input->mutex); if (input->users) { if (device_may_wakeup(dev)) disable_irq_wake(tsc->irq); else lpc32xx_setup_tsc(tsc); } mutex_unlock(&input->mutex); return 0; } static const struct dev_pm_ops lpc32xx_ts_pm_ops = { .suspend = lpc32xx_ts_suspend, .resume = lpc32xx_ts_resume, }; #define LPC32XX_TS_PM_OPS (&lpc32xx_ts_pm_ops) #else #define LPC32XX_TS_PM_OPS NULL #endif #ifdef CONFIG_OF static const struct of_device_id lpc32xx_tsc_of_match[] = { { .compatible = "nxp,lpc3220-tsc", }, { }, }; MODULE_DEVICE_TABLE(of, lpc32xx_tsc_of_match); #endif static struct platform_driver lpc32xx_ts_driver = { .probe = lpc32xx_ts_probe, .remove = lpc32xx_ts_remove, .driver = { .name = MOD_NAME, .pm = LPC32XX_TS_PM_OPS, .of_match_table = of_match_ptr(lpc32xx_tsc_of_match), }, }; module_platform_driver(lpc32xx_ts_driver); MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com"); MODULE_DESCRIPTION("LPC32XX TSC Driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:lpc32xx_ts");