--- /dev/null
+/*
+ * NXP LPC32xx SoC Key Scan Interface
+ *
+ * Authors:
+ * Kevin Wells <kevin.wells@nxp.com>
+ * Roland Stigge <stigge@antcom.de>
+ *
+ * Copyright (C) 2010 NXP Semiconductors
+ * Copyright (C) 2012 Roland Stigge
+ *
+ * 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.
+ *
+ *
+ * This controller supports square key matrices from 1x1 up to 8x8
+ */
+
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/irq.h>
+#include <linux/pm.h>
+#include <linux/platform_device.h>
+#include <linux/input.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/input/matrix_keypad.h>
+
+#define DRV_NAME "lpc32xx_keys"
+
+/*
+ * Key scanner register offsets
+ */
+#define LPC32XX_KS_DEB(x) ((x) + 0x00)
+#define LPC32XX_KS_STATE_COND(x) ((x) + 0x04)
+#define LPC32XX_KS_IRQ(x) ((x) + 0x08)
+#define LPC32XX_KS_SCAN_CTL(x) ((x) + 0x0C)
+#define LPC32XX_KS_FAST_TST(x) ((x) + 0x10)
+#define LPC32XX_KS_MATRIX_DIM(x) ((x) + 0x14) /* 1..8 */
+#define LPC32XX_KS_DATA(x, y) ((x) + 0x40 + ((y) << 2))
+
+#define LPC32XX_KSCAN_DEB_NUM_DEB_PASS(n) ((n) & 0xFF)
+
+#define LPC32XX_KSCAN_SCOND_IN_IDLE 0x0
+#define LPC32XX_KSCAN_SCOND_IN_SCANONCE 0x1
+#define LPC32XX_KSCAN_SCOND_IN_IRQGEN 0x2
+#define LPC32XX_KSCAN_SCOND_IN_SCAN_MATRIX 0x3
+
+#define LPC32XX_KSCAN_IRQ_PENDING_CLR 0x1
+
+#define LPC32XX_KSCAN_SCTRL_SCAN_DELAY(n) ((n) & 0xFF)
+
+#define LPC32XX_KSCAN_FTST_FORCESCANONCE 0x1
+#define LPC32XX_KSCAN_FTST_USE32K_CLK 0x2
+
+#define LPC32XX_KSCAN_MSEL_SELECT(n) ((n) & 0xF)
+
+struct lpc32xx_kscan_drv {
+ struct input_dev *input;
+ struct clk *clk;
+ void __iomem *kscan_base;
+ unsigned int irq;
+
+ u32 matrix_sz; /* Size of matrix in XxY, ie. 3 = 3x3 */
+ u32 deb_clks; /* Debounce clocks (based on 32KHz clock) */
+ u32 scan_delay; /* Scan delay (based on 32KHz clock) */
+
+ unsigned short *keymap; /* Pointer to key map for the scan matrix */
+ unsigned int row_shift;
+
+ u8 lastkeystates[8];
+};
+
+static void lpc32xx_mod_states(struct lpc32xx_kscan_drv *kscandat, int col)
+{
+ struct input_dev *input = kscandat->input;
+ unsigned row, changed, scancode, keycode;
+ u8 key;
+
+ key = readl(LPC32XX_KS_DATA(kscandat->kscan_base, col));
+ changed = key ^ kscandat->lastkeystates[col];
+ kscandat->lastkeystates[col] = key;
+
+ for (row = 0; changed; row++, changed >>= 1) {
+ if (changed & 1) {
+ /* Key state changed, signal an event */
+ scancode = MATRIX_SCAN_CODE(row, col,
+ kscandat->row_shift);
+ keycode = kscandat->keymap[scancode];
+ input_event(input, EV_MSC, MSC_SCAN, scancode);
+ input_report_key(input, keycode, key & (1 << row));
+ }
+ }
+}
+
+static irqreturn_t lpc32xx_kscan_irq(int irq, void *dev_id)
+{
+ struct lpc32xx_kscan_drv *kscandat = dev_id;
+ int i;
+
+ for (i = 0; i < kscandat->matrix_sz; i++)
+ lpc32xx_mod_states(kscandat, i);
+
+ writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
+
+ input_sync(kscandat->input);
+
+ return IRQ_HANDLED;
+}
+
+static int lpc32xx_kscan_open(struct input_dev *dev)
+{
+ struct lpc32xx_kscan_drv *kscandat = input_get_drvdata(dev);
+ int error;
+
+ error = clk_prepare_enable(kscandat->clk);
+ if (error)
+ return error;
+
+ writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
+
+ return 0;
+}
+
+static void lpc32xx_kscan_close(struct input_dev *dev)
+{
+ struct lpc32xx_kscan_drv *kscandat = input_get_drvdata(dev);
+
+ writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
+ clk_disable_unprepare(kscandat->clk);
+}
+
+static int lpc32xx_parse_dt(struct device *dev,
+ struct lpc32xx_kscan_drv *kscandat)
+{
+ struct device_node *np = dev->of_node;
+ u32 rows = 0, columns = 0;
+ int err;
+
+ err = matrix_keypad_parse_of_params(dev, &rows, &columns);
+ if (err)
+ return err;
+ if (rows != columns) {
+ dev_err(dev, "rows and columns must be equal!\n");
+ return -EINVAL;
+ }
+
+ kscandat->matrix_sz = rows;
+ kscandat->row_shift = get_count_order(columns);
+
+ of_property_read_u32(np, "nxp,debounce-delay-ms", &kscandat->deb_clks);
+ of_property_read_u32(np, "nxp,scan-delay-ms", &kscandat->scan_delay);
+ if (!kscandat->deb_clks || !kscandat->scan_delay) {
+ dev_err(dev, "debounce or scan delay not specified\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int lpc32xx_kscan_probe(struct platform_device *pdev)
+{
+ struct lpc32xx_kscan_drv *kscandat;
+ struct input_dev *input;
+ struct resource *res;
+ size_t keymap_size;
+ int error;
+ int irq;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "failed to get platform I/O memory\n");
+ return -EINVAL;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0 || irq >= NR_IRQS) {
+ dev_err(&pdev->dev, "failed to get platform irq\n");
+ return -EINVAL;
+ }
+
+ kscandat = devm_kzalloc(&pdev->dev, sizeof(*kscandat),
+ GFP_KERNEL);
+ if (!kscandat)
+ return -ENOMEM;
+
+ error = lpc32xx_parse_dt(&pdev->dev, kscandat);
+ if (error) {
+ dev_err(&pdev->dev, "failed to parse device tree\n");
+ return error;
+ }
+
+ keymap_size = sizeof(kscandat->keymap[0]) *
+ (kscandat->matrix_sz << kscandat->row_shift);
+ kscandat->keymap = devm_kzalloc(&pdev->dev, keymap_size, GFP_KERNEL);
+ if (!kscandat->keymap)
+ return -ENOMEM;
+
+ kscandat->input = input = devm_input_allocate_device(&pdev->dev);
+ if (!input) {
+ dev_err(&pdev->dev, "failed to allocate input device\n");
+ return -ENOMEM;
+ }
+
+ /* Setup key input */
+ input->name = pdev->name;
+ input->phys = "lpc32xx/input0";
+ input->id.vendor = 0x0001;
+ input->id.product = 0x0001;
+ input->id.version = 0x0100;
+ input->open = lpc32xx_kscan_open;
+ input->close = lpc32xx_kscan_close;
+ input->dev.parent = &pdev->dev;
+
+ input_set_capability(input, EV_MSC, MSC_SCAN);
+
+ error = matrix_keypad_build_keymap(NULL, NULL,
+ kscandat->matrix_sz,
+ kscandat->matrix_sz,
+ kscandat->keymap, kscandat->input);
+ if (error) {
+ dev_err(&pdev->dev, "failed to build keymap\n");
+ return error;
+ }
+
+ input_set_drvdata(kscandat->input, kscandat);
+
+ kscandat->kscan_base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(kscandat->kscan_base))
+ return PTR_ERR(kscandat->kscan_base);
+
+ /* Get the key scanner clock */
+ kscandat->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(kscandat->clk)) {
+ dev_err(&pdev->dev, "failed to get clock\n");
+ return PTR_ERR(kscandat->clk);
+ }
+
+ /* Configure the key scanner */
+ error = clk_prepare_enable(kscandat->clk);
+ if (error)
+ return error;
+
+ writel(kscandat->deb_clks, LPC32XX_KS_DEB(kscandat->kscan_base));
+ writel(kscandat->scan_delay, LPC32XX_KS_SCAN_CTL(kscandat->kscan_base));
+ writel(LPC32XX_KSCAN_FTST_USE32K_CLK,
+ LPC32XX_KS_FAST_TST(kscandat->kscan_base));
+ writel(kscandat->matrix_sz,
+ LPC32XX_KS_MATRIX_DIM(kscandat->kscan_base));
+ writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
+ clk_disable_unprepare(kscandat->clk);
+
+ error = devm_request_irq(&pdev->dev, irq, lpc32xx_kscan_irq, 0,
+ pdev->name, kscandat);
+ if (error) {
+ dev_err(&pdev->dev, "failed to request irq\n");
+ return error;
+ }
+
+ error = input_register_device(kscandat->input);
+ if (error) {
+ dev_err(&pdev->dev, "failed to register input device\n");
+ return error;
+ }
+
+ platform_set_drvdata(pdev, kscandat);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int lpc32xx_kscan_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);
+ struct input_dev *input = kscandat->input;
+
+ mutex_lock(&input->mutex);
+
+ if (input->users) {
+ /* Clear IRQ and disable clock */
+ writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
+ clk_disable_unprepare(kscandat->clk);
+ }
+
+ mutex_unlock(&input->mutex);
+ return 0;
+}
+
+static int lpc32xx_kscan_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);
+ struct input_dev *input = kscandat->input;
+ int retval = 0;
+
+ mutex_lock(&input->mutex);
+
+ if (input->users) {
+ /* Enable clock and clear IRQ */
+ retval = clk_prepare_enable(kscandat->clk);
+ if (retval == 0)
+ writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
+ }
+
+ mutex_unlock(&input->mutex);
+ return retval;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(lpc32xx_kscan_pm_ops, lpc32xx_kscan_suspend,
+ lpc32xx_kscan_resume);
+
+static const struct of_device_id lpc32xx_kscan_match[] = {
+ { .compatible = "nxp,lpc3220-key" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, lpc32xx_kscan_match);
+
+static struct platform_driver lpc32xx_kscan_driver = {
+ .probe = lpc32xx_kscan_probe,
+ .driver = {
+ .name = DRV_NAME,
+ .pm = &lpc32xx_kscan_pm_ops,
+ .of_match_table = lpc32xx_kscan_match,
+ }
+};
+
+module_platform_driver(lpc32xx_kscan_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com>");
+MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
+MODULE_DESCRIPTION("Key scanner driver for LPC32XX devices");
Code Review / kvmfornfv.git / blobdiff