This patch adds a driver for the key scan interface of the LPC32xx SoC
Signed-off-by: Roland Stigge <stigge@xxxxxxxxx>
---
Applies to v3.5-rc6
Changes since v8:
* Optimized lpc32xx_mod_states() to shift "changed" word and break on 0
* lpc32xx_parse_dt(): Return -EINVAL instead of -ENXIO
* kfree() of keymap _after_ stopping IRQ
Changes since v7:
* Bugfix: enable clock in open() before accessing reg
Changes since v6:
* Clear IRQ in LPC32XX_KS_IRQ register in lpc32xx_kscan_{open,close}
* Declare lpc32xx_parse_dt() static
* Pass kscandat to lpc32xx_parse_dt() instead of pdev
* Moved keymap allocation to probe()
* Use clk_prepare_enable() and clk_disable_unprepare() in probe(),
around actual register access
* Do input_allocate_device() earlier, after kscandat allocation
* Do input_register_device() last in probe()
* suspend()/resume(): take mutex, and guard against (users == 0)
Changes since v5:
* Handle return code from matrix_keypad_build_keymap()
* Remove platform data structure and integrate into device struct
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 | 381 ++++++++++++++++
4 files changed, 420 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 +1,381 @@
+/*
+ * NXP LPC32xx SoC Key Scan Interface
+ *
+ * Authors:
+ * Kevin Wells <kevin.wells@xxxxxxx>
+ * Roland Stigge <stigge@xxxxxxxxx>
+ *
+ * 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;
+ u8 lastkeystates[8];
+ u32 io_p_start;
+ u32 io_p_size;
+ 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;
+};
+
+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];
+ 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(kscandat->input, EV_MSC, MSC_SCAN,
+ scancode);
+ input_report_key(kscandat->input, keycode,
+ key & (1 << row));
+ }
+ }
+}
+
+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->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 lpc32xx_kscan_drv *kscandat)
+{
+ struct device *dev = &kscandat->input->dev;
+ struct device_node *np = dev->parent->of_node;
+ u32 rows, columns;
+
+ 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");
+ 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 __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;
+ }
+
+ kscandat->input = input_allocate_device();
+ if (kscandat->input == NULL) {
+ dev_err(&pdev->dev, "failed to allocate device\n");
+ error = -ENOMEM;
+ goto out1;
+ }
+
+ 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 out2;
+ }
+
+ 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 out2;
+ }
+ 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 out3;
+ }
+
+ /* 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 out4;
+ }
+
+ 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 out5;
+ }
+ platform_set_drvdata(pdev, kscandat);
+
+ /* 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;
+
+ error = lpc32xx_parse_dt(kscandat);
+ if (error) {
+ dev_err(&pdev->dev, "failed to parse device tree\n");
+ goto out5;
+ }
+
+ kscandat->keymap = kzalloc(sizeof(kscandat->keymap[0]) *
+ (kscandat->matrix_sz << kscandat->row_shift),
+ GFP_KERNEL);
+ if (!kscandat->keymap) {
+ dev_err(&pdev->dev, "could not allocate memory for keymap\n");
+ error = -ENOMEM;
+ goto out5;
+ }
+
+ 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");
+ goto out6;
+ }
+
+ input_set_drvdata(kscandat->input, kscandat);
+ input_set_capability(kscandat->input, EV_MSC, MSC_SCAN);
+
+ /* Configure the key scanner */
+ clk_prepare_enable(kscandat->clk);
+ 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 = request_irq(irq, lpc32xx_kscan_irq, 0, pdev->name, kscandat);
+ if (error) {
+ dev_err(&pdev->dev, "failed to request irq\n");
+ goto out6;
+ }
+
+ error = input_register_device(kscandat->input);
+ if (error) {
+ dev_err(&pdev->dev, "failed to register input device\n");
+ goto out7;
+ }
+
+ return 0;
+
+out7:
+ free_irq(irq, pdev);
+out6:
+ kfree(kscandat->keymap);
+out5:
+ clk_put(kscandat->clk);
+out4:
+ iounmap(kscandat->kscan_base);
+out3:
+ release_mem_region(kscandat->io_p_start, kscandat->io_p_size);
+out2:
+ input_free_device(kscandat->input);
+out1:
+ kfree(kscandat);
+
+ return error;
+}
+
+static int __devexit lpc32xx_kscan_remove(struct platform_device *pdev)
+{
+ struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);
+
+ 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);
+ input_unregister_device(kscandat->input);
+ kfree(kscandat->keymap);
+ 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);
+
+ mutex_lock(&kscandat->input->mutex);
+
+ if (kscandat->input->users) {
+ /* Clear IRQ and disable clock */
+ writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
+ clk_disable_unprepare(kscandat->clk);
+ }
+
+ mutex_unlock(&kscandat->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);
+
+ mutex_lock(&kscandat->input->mutex);
+
+ if (kscandat->input->users) {
+ /* Enable clock and clear IRQ */
+ clk_prepare_enable(kscandat->clk);
+ writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
+ }
+
+ mutex_unlock(&kscandat->input->mutex);
+ 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@xxxxxxx>");
+MODULE_AUTHOR("Roland Stigge <stigge@xxxxxxxxx>");
+MODULE_DESCRIPTION("Key scanner driver for LPC32XX devices");
--
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