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    Subject[PATCH v5] input: keyboard: Add keys driver for the LPC32xx SoC
    Date
    This patch adds a driver for the key scan interface of the LPC32xx SoC

    Signed-off-by: Roland Stigge <stigge@antcom.de>
    For the DT binding: Acked-by: Rob Herring <rob.herring@calxeda.con>

    ---
    Applies to v3.5-rc3

    Changes since v4:
    * Remove irq from struct lpc32xx_kscan_drv

    Changes since v3:
    * Make driver DT-only since LPC32xx is converted to DT anyway now.
    * Use MATRIX_SCAN_CODE()
    * Use matrix_keypad_build_keymap()
    * Emit MSC_SCAN also
    * Use PTR_ERR() on error handling
    * Rename return value to error
    * Removed unnecessary '&' on initializations with function pointers
    * Use CONFIG_PM_SLEEP, dev_pm_ops, SIMPLE_DEV_PM_OPS instead of CONFIG_PM
    * Removed devm_*() management
    * Re-enabled clock for period of probe()

    Changes since v2:
    * Fixed case of lpc32XX_* -> lpc32xx_*
    * Removed unnecessary casts
    * Removed unnecessary unlikely()
    * Use unsigned for key bits
    * Included Russell's lpc32xx_mod_states() algorithm change suggestion
    * Replaced (res == NULL) with (!res)
    * clk_enable() -> clk_prepare_enable()
    * Moved clk_prepare_enable() and clk_disable_unprepare() to input's
    open()/close() callbacks to save power
    * Handle clk_prepare_enable() return value appropriately
    * DT: Use "keypad,num-rows", "keypad,num-columns" and "linux,keymap" properties

    Changes since v1:
    * Removed devm_kfree(), lpc32XX_free_dt(), iounmap(), release_mem_region()
    * Changed __raw_writel()+__raw_readl() to writel()+readl()

    Thanks to Axel Lin, Russell King, Rob Herring, Shubhrajyoti and Dmitry Torokhov
    for reviewing!

    Documentation/devicetree/bindings/input/lpc32xx-key.txt | 28 +
    drivers/input/keyboard/Kconfig | 10
    drivers/input/keyboard/Makefile | 1
    drivers/input/keyboard/lpc32xx-keys.c | 376 ++++++++++++++++
    4 files changed, 415 insertions(+)

    --- /dev/null
    +++ linux-2.6/Documentation/devicetree/bindings/input/lpc32xx-key.txt
    @@ -0,0 +1,28 @@
    +NXP LPC32xx Key Scan Interface
    +
    +Required Properties:
    +- compatible: Should be "nxp,lpc3220-key"
    +- reg: Physical base address of the controller and length of memory mapped
    + region.
    +- interrupts: The interrupt number to the cpu.
    +- keypad,num-rows: Number of rows and columns, e.g. 1: 1x1, 6: 6x6
    +- keypad,num-columns: Must be equal to keypad,num-rows since LPC32xx only
    + supports square matrices
    +- nxp,debounce-delay-ms: Debounce delay in ms
    +- nxp,scan-delay-ms: Repeated scan period in ms
    +- linux,keymap: the key-code to be reported when the key is pressed
    + and released, see also
    + Documentation/devicetree/bindings/input/matrix-keymap.txt
    +
    +Example:
    +
    + key@40050000 {
    + compatible = "nxp,lpc3220-key";
    + reg = <0x40050000 0x1000>;
    + interrupts = <54 0>;
    + keypad,num-rows = <1>;
    + keypad,num-columns = <1>;
    + nxp,debounce-delay-ms = <3>;
    + nxp,scan-delay-ms = <34>;
    + linux,keymap = <0x00000002>;
    + };
    --- linux-2.6.orig/drivers/input/keyboard/Kconfig
    +++ linux-2.6/drivers/input/keyboard/Kconfig
    @@ -332,6 +332,16 @@ config KEYBOARD_LOCOMO
    To compile this driver as a module, choose M here: the
    module will be called locomokbd.

    +config KEYBOARD_LPC32XX
    + tristate "LPC32XX matrix key scanner support"
    + depends on ARCH_LPC32XX && OF
    + help
    + Say Y here if you want to use NXP LPC32XX SoC key scanner interface,
    + connected to a key matrix.
    +
    + To compile this driver as a module, choose M here: the
    + module will be called lpc32xx-keys.
    +
    config KEYBOARD_MAPLE
    tristate "Maple bus keyboard"
    depends on SH_DREAMCAST && MAPLE
    --- linux-2.6.orig/drivers/input/keyboard/Makefile
    +++ linux-2.6/drivers/input/keyboard/Makefile
    @@ -26,6 +26,7 @@ obj-$(CONFIG_KEYBOARD_LKKBD) += lkkbd.o
    obj-$(CONFIG_KEYBOARD_LM8323) += lm8323.o
    obj-$(CONFIG_KEYBOARD_LM8333) += lm8333.o
    obj-$(CONFIG_KEYBOARD_LOCOMO) += locomokbd.o
    +obj-$(CONFIG_KEYBOARD_LPC32XX) += lpc32xx-keys.o
    obj-$(CONFIG_KEYBOARD_MAPLE) += maple_keyb.o
    obj-$(CONFIG_KEYBOARD_MATRIX) += matrix_keypad.o
    obj-$(CONFIG_KEYBOARD_MAX7359) += max7359_keypad.o
    --- /dev/null
    +++ linux-2.6/drivers/input/keyboard/lpc32xx-keys.c
    @@ -0,0 +1,376 @@
    +/*
    + * 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)
    +
    +/*
    + * Key scanner configuration structure
    + */
    +struct lpc32xx_kscan_cfg {
    + u32 matrix_sz; /* Size of matrix in XxY, ie. 3 = 3x3 */
    + unsigned short *keymap; /* Pointer to key map for the scan matrix */
    + u32 deb_clks; /* Debounce clocks (based on 32KHz clock) */
    + u32 scan_delay; /* Scan delay (based on 32KHz clock) */
    + int row_shift;
    +};
    +
    +struct lpc32xx_kscan_drv {
    + struct input_dev *input;
    + struct lpc32xx_kscan_cfg *kscancfg;
    + struct clk *clk;
    + void __iomem *kscan_base;
    + u8 lastkeystates[8];
    + u32 io_p_start;
    + u32 io_p_size;
    +};
    +
    +static void lpc32xx_mod_states(struct lpc32xx_kscan_drv *kscandat, int col)
    +{
    + u8 key;
    + int row;
    + unsigned changed, scancode, keycode;
    +
    + key = readl(LPC32XX_KS_DATA(kscandat->kscan_base, col));
    + changed = key ^ kscandat->lastkeystates[col];
    + if (changed) {
    + for (row = 0; row < kscandat->kscancfg->matrix_sz; row++) {
    + if (changed & (1 << row)) {
    + /* Key state changed, signal an event */
    + scancode = MATRIX_SCAN_CODE(
    + row, col, kscandat->kscancfg->row_shift);
    + keycode = kscandat->kscancfg->keymap[scancode];
    + input_event(kscandat->input, EV_MSC, MSC_SCAN,
    + scancode);
    + input_report_key(kscandat->input, keycode,
    + key & (1 << row));
    + }
    + }
    +
    + kscandat->lastkeystates[col] = key;
    + }
    +}
    +
    +static irqreturn_t lpc32xx_kscan_irq(int irq, void *dev_id)
    +{
    + int i;
    + struct lpc32xx_kscan_drv *kscandat = dev_id;
    +
    + for (i = 0; i < kscandat->kscancfg->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);
    +
    + return clk_prepare_enable(kscandat->clk);
    +}
    +
    +static void lpc32xx_kscan_close(struct input_dev *dev)
    +{
    + struct lpc32xx_kscan_drv *kscandat = input_get_drvdata(dev);
    +
    + clk_disable_unprepare(kscandat->clk);
    +}
    +
    +static struct lpc32xx_kscan_cfg *lpc32xx_parse_dt(struct device *dev)
    +{
    + struct lpc32xx_kscan_cfg *pdata;
    + struct device_node *np = dev->of_node;
    + u32 rows, columns;
    +
    + pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
    + if (!pdata) {
    + dev_err(dev, "could not allocate memory for platform data\n");
    + return NULL;
    + }
    +
    + of_property_read_u32(np, "keypad,num-rows", &rows);
    + of_property_read_u32(np, "keypad,num-columns", &columns);
    + if (!rows || rows != columns) {
    + dev_err(dev, "rows and columns must be specified and be equal!\n");
    + goto out1;
    + }
    +
    + pdata->matrix_sz = rows;
    + pdata->row_shift = get_count_order(columns);
    +
    + of_property_read_u32(np, "nxp,debounce-delay-ms", &pdata->deb_clks);
    + of_property_read_u32(np, "nxp,scan-delay-ms", &pdata->scan_delay);
    + if (!pdata->deb_clks || !pdata->scan_delay) {
    + dev_err(dev, "debounce or scan delay not specified\n");
    + goto out1;
    + }
    +
    + pdata->keymap = kzalloc(sizeof(pdata->keymap[0]) *
    + (rows << pdata->row_shift), GFP_KERNEL);
    + if (!pdata->keymap) {
    + dev_err(dev, "could not allocate memory for keymap\n");
    + goto out1;
    + }
    +
    + return pdata;
    +out1:
    + kfree(pdata);
    + return NULL;
    +}
    +
    +static int __devinit lpc32xx_kscan_probe(struct platform_device *pdev)
    +{
    + struct lpc32xx_kscan_drv *kscandat;
    + struct resource *res;
    + int error;
    + int irq;
    +
    + kscandat = kzalloc(sizeof(struct lpc32xx_kscan_drv), GFP_KERNEL);
    + if (!kscandat) {
    + dev_err(&pdev->dev, "failed to allocate memory\n");
    + return -ENOMEM;
    + }
    +
    + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    + if (!res) {
    + dev_err(&pdev->dev, "failed to get platform I/O memory\n");
    + error = -EBUSY;
    + goto out1;
    + }
    +
    + res = request_mem_region(res->start, resource_size(res), pdev->name);
    + if (!res) {
    + dev_err(&pdev->dev, "failed to request I/O memory\n");
    + error = -EBUSY;
    + goto out1;
    + }
    + kscandat->io_p_start = res->start;
    + kscandat->io_p_size = resource_size(res);
    +
    + kscandat->kscan_base = ioremap(res->start, resource_size(res));
    + if (!kscandat->kscan_base) {
    + dev_err(&pdev->dev, "failed to remap I/O memory\n");
    + error = -EBUSY;
    + goto out2;
    + }
    +
    + /* Get the key scanner clock */
    + kscandat->clk = clk_get(&pdev->dev, NULL);
    + if (IS_ERR(kscandat->clk)) {
    + dev_err(&pdev->dev, "failed to get clock\n");
    + error = PTR_ERR(kscandat->clk);
    + goto out3;
    + }
    + clk_enable(kscandat->clk);
    +
    + irq = platform_get_irq(pdev, 0);
    + if ((irq < 0) || (irq >= NR_IRQS)) {
    + dev_err(&pdev->dev, "failed to get platform irq\n");
    + error = -EINVAL;
    + goto out4;
    + }
    + error = request_irq(irq, lpc32xx_kscan_irq, 0, pdev->name, kscandat);
    + if (error) {
    + dev_err(&pdev->dev, "failed to request irq\n");
    + goto out4;
    + }
    +
    + kscandat->input = input_allocate_device();
    + if (kscandat->input == NULL) {
    + dev_err(&pdev->dev, "failed to allocate device\n");
    + error = -ENOMEM;
    + goto out5;
    + }
    +
    + kscandat->kscancfg = lpc32xx_parse_dt(&pdev->dev);
    + if (!kscandat->kscancfg) {
    + dev_err(&pdev->dev, "failed to get platform data\n");
    + error = -EINVAL;
    + goto out6;
    + }
    +
    + /* Setup key input */
    + kscandat->input->evbit[0] = BIT_MASK(EV_KEY);
    + kscandat->input->name = pdev->name;
    + kscandat->input->phys = "matrix-keys/input0";
    + kscandat->input->id.vendor = 0x0001;
    + kscandat->input->id.product = 0x0001;
    + kscandat->input->id.version = 0x0100;
    + kscandat->input->open = lpc32xx_kscan_open;
    + kscandat->input->close = lpc32xx_kscan_close;
    + kscandat->input->dev.parent = &pdev->dev;
    +
    + matrix_keypad_build_keymap(NULL, NULL, kscandat->kscancfg->matrix_sz,
    + kscandat->kscancfg->matrix_sz,
    + kscandat->kscancfg->keymap, kscandat->input);
    +
    + platform_set_drvdata(pdev, kscandat);
    +
    + input_set_drvdata(kscandat->input, kscandat);
    + input_set_capability(kscandat->input, EV_MSC, MSC_SCAN);
    +
    + error = input_register_device(kscandat->input);
    + if (error) {
    + dev_err(&pdev->dev, "failed to register input device\n");
    + goto out6;
    + }
    +
    + /* Configure the key scanner */
    + writel(kscandat->kscancfg->deb_clks,
    + LPC32XX_KS_DEB(kscandat->kscan_base));
    + writel(kscandat->kscancfg->scan_delay,
    + LPC32XX_KS_SCAN_CTL(kscandat->kscan_base));
    + writel(LPC32XX_KSCAN_FTST_USE32K_CLK,
    + LPC32XX_KS_FAST_TST(kscandat->kscan_base));
    + writel(kscandat->kscancfg->matrix_sz,
    + LPC32XX_KS_MATRIX_DIM(kscandat->kscan_base));
    + writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
    + clk_disable(kscandat->clk);
    + return 0;
    +
    +out6:
    + input_free_device(kscandat->input);
    +out5:
    + free_irq(irq, pdev);
    +out4:
    + clk_disable(kscandat->clk);
    + clk_put(kscandat->clk);
    +out3:
    + iounmap(kscandat->kscan_base);
    +out2:
    + release_mem_region(kscandat->io_p_start, kscandat->io_p_size);
    +out1:
    + kfree(kscandat);
    +
    + return error;
    +}
    +
    +static int __devexit lpc32xx_kscan_remove(struct platform_device *pdev)
    +{
    + struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);
    +
    + input_unregister_device(kscandat->input);
    + free_irq(platform_get_irq(pdev, 0), pdev);
    + clk_put(kscandat->clk);
    + iounmap(kscandat->kscan_base);
    + release_mem_region(kscandat->io_p_start, kscandat->io_p_size);
    + kfree(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);
    +
    + /* Clear IRQ and disable clock */
    + writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
    + clk_disable_unprepare(kscandat->clk);
    +
    + 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);
    +
    + /* Enable clock and clear IRQ */
    + clk_prepare_enable(kscandat->clk);
    + writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
    +
    + return 0;
    +}
    +#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,
    + .remove = __devexit_p(lpc32xx_kscan_remove),
    + .driver = {
    + .name = DRV_NAME,
    + .owner = THIS_MODULE,
    + .pm = &lpc32xx_kscan_pm_ops,
    + .of_match_table = of_match_ptr(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");

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      Last update: 2012-06-18 22:41    [W:4.040 / U:0.016 seconds]
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