[PATCH v3 1/2] input: keyboard: Add keys driver for the LPC32xx SoC

[PATCH v3 1/2] input: keyboard: Add keys driver for the LPC32xx SoC

[Roland Stigge]

This patch adds a driver for the key scan interface of the LPC32xx SoC

Signed-off-by: Roland Stigge <stigge@antcom.de>

---
Applies to v3.4-rc4

Please pick this patch for the input subsystem.

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

Thanks to Axel Lin and Russell King 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                   |  382 ++++++++++++++++
 4 files changed, 421 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
@@ -318,6 +318,16 @@ 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
+	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
@@ -25,6 +25,7 @@ obj-$(CONFIG_KEYBOARD_HP7XX)		+= jornada
 obj-$(CONFIG_KEYBOARD_LKKBD)		+= lkkbd.o
 obj-$(CONFIG_KEYBOARD_LM8323)		+= lm8323.o
 obj-$(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 +1,382 @@
+/*
+ * 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.
+ */
+
+#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>
+
+/*
+ * 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)
+#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 platform configuration structure
+ */
+struct lpc32xx_kscan_cfg {
+	u32	matrix_sz;	/* Size of matrix in XxY, ie. 3 = 3x3 */
+	int	*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) */
+};
+
+struct lpc32xx_kscan_drv {
+	struct input_dev *input;
+	struct lpc32xx_kscan_cfg *kscancfg;
+	struct clk *clk;
+	void __iomem *kscan_base;
+	int irq;
+	u8 lastkeystates[8];
+};
+
+static void lpc32xx_mod_states(struct lpc32xx_kscan_drv *kscandat, int off)
+{
+	u8 key;
+	int j;
+	unsigned changed, scancode, keycode;
+
+	key = readl(LPC32XX_KS_DATA(kscandat->kscan_base, off));
+	changed = key ^ kscandat->lastkeystates[off];
+	if (changed) {
+		for (j = 0; j < kscandat->kscancfg->matrix_sz; j++) {
+			if (changed & (1 << j)) {
+				/* Key state changed, signal an event */
+				scancode =
+				    (j * kscandat->kscancfg->matrix_sz) + off;
+				keycode = kscandat->kscancfg->keymap[scancode];
+				input_report_key(kscandat->input, keycode,
+						 key & (1 << j));
+			}
+		}
+
+		kscandat->lastkeystates[off] = 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);
+}
+
+#ifdef CONFIG_OF
+static struct lpc32xx_kscan_cfg *lpc32xx_parse_dt(struct device *dev)
+{
+	struct lpc32xx_kscan_cfg *pdata;
+	struct device_node *np = dev->of_node;
+	int key_count;
+	int i;
+	u32 rows, columns;
+	const __be32 *prop;
+	int proplen;
+
+	pdata = devm_kzalloc(dev, 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");
+		return NULL;
+	}
+
+	pdata->matrix_sz = rows;
+	key_count = rows * 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");
+		return NULL;
+	}
+
+	pdata->keymap = devm_kzalloc(dev, sizeof(int) * key_count, GFP_KERNEL);
+	if (!pdata->keymap) {
+		dev_err(dev, "could not allocate memory for keymap\n");
+		return NULL;
+	}
+
+	prop = of_get_property(np, "linux,keymap", &proplen);
+	if (!prop) {
+		dev_err(dev, "linux,keymap not specified\n");
+		return NULL;
+	}
+
+	if (proplen % sizeof(u32)) {
+		dev_err(dev, "bad linux,keymap property size: %d\n", proplen);
+		return NULL;
+	}
+	proplen /= sizeof(u32);
+
+	for (i = 0; i < proplen; i++) {
+		u32 tmp = be32_to_cpup(prop + i);
+		u32 row, column, key_code;
+
+		row = (tmp >> 24) & 0xff;
+		column = (tmp >> 16) & 0xff;
+		key_code = tmp & 0xffff;
+		pdata->keymap[row * columns + column] = key_code;
+	}
+
+	return pdata;
+}
+#else
+static struct lpc32xx_kscan_cfg *lpc32xx_parse_dt(struct device *dev)
+{
+	return NULL;
+}
+#endif
+
+static int __devinit lpc32xx_kscan_probe(struct platform_device *pdev)
+{
+	struct lpc32xx_kscan_drv *kscandat;
+	struct resource *res;
+	int retval, i, keynum;
+
+	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");
+		retval = -EBUSY;
+		goto out1;
+	}
+
+	kscandat->kscan_base = devm_request_and_ioremap(&pdev->dev, res);
+	if (kscandat->kscan_base == NULL) {
+		dev_err(&pdev->dev, "failed to request and remap I/O memory\n");
+		retval = -EBUSY;
+		goto out1;
+	}
+
+	/* 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");
+		retval = -ENODEV;
+		goto out1;
+	}
+
+	kscandat->irq = platform_get_irq(pdev, 0);
+	if ((kscandat->irq < 0) || (kscandat->irq >= NR_IRQS)) {
+		dev_err(&pdev->dev, "failed to get platform irq\n");
+		retval = -EINVAL;
+		goto out2;
+	}
+	retval = request_irq(kscandat->irq, lpc32xx_kscan_irq,
+			     0, pdev->name, kscandat);
+	if (retval) {
+		dev_err(&pdev->dev, "failed to request irq\n");
+		goto out2;
+	}
+
+	kscandat->input = input_allocate_device();
+	if (kscandat->input == NULL) {
+		dev_err(&pdev->dev, "failed to allocate device\n");
+		retval = -ENOMEM;
+		goto out3;
+	}
+
+	if (pdev->dev.of_node)
+		kscandat->kscancfg = lpc32xx_parse_dt(&pdev->dev);
+	else
+		kscandat->kscancfg = pdev->dev.platform_data;
+	if (!kscandat->kscancfg) {
+		dev_err(&pdev->dev, "failed to get platform data\n");
+		retval = -EINVAL;
+		goto out4;
+	}
+
+	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->dev.parent	=  &pdev->dev;
+	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;
+	keynum = kscandat->kscancfg->matrix_sz * kscandat->kscancfg->matrix_sz;
+	for (i = 0; i < keynum; i++)
+		__set_bit(kscandat->kscancfg->keymap[i],
+			kscandat->input->keybit);
+
+	input_set_drvdata(kscandat->input, kscandat);
+	input_set_capability(kscandat->input, EV_MSC, MSC_SCAN);
+
+	retval = input_register_device(kscandat->input);
+	if (retval) {
+		dev_err(&pdev->dev, "failed to register input device\n");
+		goto out4;
+	}
+
+	/* 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));
+
+	return 0;
+
+out4:
+	input_free_device(kscandat->input);
+out3:
+	free_irq(kscandat->irq, pdev);
+out2:
+	clk_put(kscandat->clk);
+out1:
+	kfree(kscandat);
+
+	return retval;
+}
+
+static int __devexit lpc32xx_kscan_remove(struct platform_device *pdev)
+{
+	struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);
+
+	free_irq(kscandat->irq, pdev);
+	input_unregister_device(kscandat->input);
+	clk_put(kscandat->clk);
+	kfree(kscandat);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int lpc32xx_kscan_suspend(struct platform_device *pdev,
+	pm_message_t state)
+{
+	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 platform_device *pdev)
+{
+	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;
+}
+#else
+#define lpc32xx_kscan_suspend	NULL
+#define lpc32xx_kscan_resume	NULL
+#endif
+
+#ifdef CONFIG_OF
+static const struct of_device_id lpc32xx_kscan_match[] = {
+	{ .compatible = "nxp,lpc3220-key" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, lpc32xx_kscan_match);
+#endif
+
+static struct platform_driver lpc32xx_kscan_driver = {
+	.probe		= lpc32xx_kscan_probe,
+	.remove		= __devexit_p(lpc32xx_kscan_remove),
+	.suspend	= lpc32xx_kscan_suspend,
+	.resume		= lpc32xx_kscan_resume,
+	.driver		= {
+		.name	= "lpc32xx_keys",
+		.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");

[PATCH v3 2/2] ARM: LPC32xx: Make platform use key driver

[Roland Stigge]

This patch connects the lpc32xx-key driver to the LPC32xx platform (via
lpc32xx.dtsi), and more specifically to the reference board via its dts file.
The clock.c file needs to be changed to match the automatic device name to its
clock.

Signed-off-by: Roland Stigge <stigge@antcom.de>

---
Applies to v3.4-rc4 + LPC32xx DT patches

Please pick this patch for the arm-soc subsystem.

Changes since v2:
* DT: Use "keypad,num-rows", "keypad,num-columns" and "linux,keymap" properties

 arch/arm/boot/dts/lpc32xx.dtsi |    2 ++
 arch/arm/boot/dts/phy3250.dts  |    9 +++++++++
 arch/arm/mach-lpc32xx/clock.c  |    2 +-
 3 files changed, 12 insertions(+), 1 deletion(-)

--- linux-2.6.orig/arch/arm/boot/dts/lpc32xx.dtsi
+++ linux-2.6/arch/arm/boot/dts/lpc32xx.dtsi
@@ -285,6 +285,8 @@
 			key@40050000 {
 				compatible = "nxp,lpc3220-key";
 				reg = <0x40050000 0x1000>;
+				interrupts = <54 0>;
+				status = "disable";
 			};
 
 		};
--- linux-2.6.orig/arch/arm/boot/dts/phy3250.dts
+++ linux-2.6/arch/arm/boot/dts/phy3250.dts
@@ -124,6 +124,15 @@
 			tsc@40048000 {
 				status = "okay";
 			};
+
+			key@40050000 {
+				status = "okay";
+				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/arch/arm/mach-lpc32xx/clock.c
+++ linux-2.6/arch/arm/mach-lpc32xx/clock.c
@@ -1131,7 +1131,7 @@ static struct clk_lookup lookups[] = {
 	CLKDEV_INIT("31020300.i2c", NULL, &clk_i2c2),
 	CLKDEV_INIT("dev:ssp0", NULL, &clk_ssp0),
 	CLKDEV_INIT("dev:ssp1", NULL, &clk_ssp1),
-	CLKDEV_INIT("lpc32xx_keys.0", NULL, &clk_kscan),
+	CLKDEV_INIT("40050000.key", NULL, &clk_kscan),
 	CLKDEV_INIT("lpc32xx-nand.0", "nand_ck", &clk_nand),
 	CLKDEV_INIT("200b0000.flash", "nand_ck_mlc", &clk_nand_mlc),
 	CLKDEV_INIT("40048000.adc", NULL, &clk_adc),