Add driver for Broadcom's keypad controller.

Broadcom Keypad controller is used to interface a SoC with a matrix-type
keypad device. The keypad controller supports multiple row and column lines.
A key can be placed at each intersection of a unique row and a unique column.
The keypad controller can sense a key-press and key-release and report the
event using a interrupt to the cpu.

Reviewed-by: Ray Jui <r...@broadcom.com>
Signed-off-by: Scott Branden <sbran...@broadcom.com>
---
 drivers/input/keyboard/Kconfig      |  10 +
 drivers/input/keyboard/Makefile     |   1 +
 drivers/input/keyboard/bcm-keypad.c | 463 ++++++++++++++++++++++++++++++++++++
 3 files changed, 474 insertions(+)
 create mode 100644 drivers/input/keyboard/bcm-keypad.c

diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index a5d9b3f..3a0c0f2 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -676,4 +676,14 @@ config KEYBOARD_CAP11XX
          To compile this driver as a module, choose M here: the
          module will be called cap11xx.
 
+config KEYBOARD_BCM
+       tristate "Broadcom keypad driver"
+       select INPUT_MATRIXKMAP
+       default ARCH_BCM_CYGNUS
+       help
+         Say Y here if you want to use Broadcom keypad.
+
+         To compile this driver as a module, choose M here: the
+         module will be called bcm-keypad.
+
 endif
diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
index febafa5..3cff8f6 100644
--- a/drivers/input/keyboard/Makefile
+++ b/drivers/input/keyboard/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_KEYBOARD_ADP5589)                += 
adp5589-keys.o
 obj-$(CONFIG_KEYBOARD_AMIGA)           += amikbd.o
 obj-$(CONFIG_KEYBOARD_ATARI)           += atakbd.o
 obj-$(CONFIG_KEYBOARD_ATKBD)           += atkbd.o
+obj-$(CONFIG_KEYBOARD_BCM)             += bcm-keypad.o
 obj-$(CONFIG_KEYBOARD_BFIN)            += bf54x-keys.o
 obj-$(CONFIG_KEYBOARD_CAP11XX)         += cap11xx.o
 obj-$(CONFIG_KEYBOARD_CLPS711X)                += clps711x-keypad.o
diff --git a/drivers/input/keyboard/bcm-keypad.c 
b/drivers/input/keyboard/bcm-keypad.c
new file mode 100644
index 0000000..0fde149
--- /dev/null
+++ b/drivers/input/keyboard/bcm-keypad.c
@@ -0,0 +1,463 @@
+/*
+ * Copyright (C) 2014 Broadcom Corporation
+ *
+ * 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 version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/bitops.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/sizes.h>
+#include <linux/stddef.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/slab.h>
+#include <linux/clk.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <asm/memory.h>
+#include <linux/io.h>
+#include <linux/input/matrix_keypad.h>
+
+#define DEFAULT_CLK_HZ                  31250
+/* Repeat period (ms) */
+#define KEY_REPEAT_PERIOD               100
+/* First time press dly (ms) */
+#define KEY_REPEAT_DELAY                400
+#define MAX_ROWS                        8
+#define MAX_COLS                        8
+
+/* Register/field definitions */
+#define KPCR_OFFSET                          0x00000080
+#define KPCR_MODE                       0x00000002
+#define KPCR_MODE_SHIFT                 1
+#define KPCR_MODE_MASK                  1
+#define KPCR_ENABLE                     0x00000001
+#define KPCR_STATUSFILTERENABLE         0x00008000
+#define KPCR_STATUSFILTERTYPE_SHIFT          12
+#define KPCR_COLFILTERENABLE            0x00000800
+#define KPCR_COLFILTERTYPE_SHIFT             8
+#define KPCR_ROWWIDTH_SHIFT                  20
+#define KPCR_COLUMNWIDTH_SHIFT               16
+
+#define KPIOR_OFFSET                         0x00000084
+#define KPIOR_ROWOCONTRL_SHIFT               24
+#define KPIOR_ROWOCONTRL_MASK                0xFF000000
+#define KPIOR_COLUMNOCONTRL_SHIFT            16
+#define KPIOR_COLUMNOCONTRL_MASK             0x00FF0000
+#define KPIOR_COLUMN_IO_DATA_SHIFT           0
+
+#define KPEMR0_OFFSET                        0x00000090
+#define KPEMR1_OFFSET                        0x00000094
+#define KPEMR2_OFFSET                        0x00000098
+#define KPEMR3_OFFSET                        0x0000009C
+#define KPEMR_EDGETYPE_BOTH 3
+
+#define KPSSR0_OFFSET                        0x000000A0
+#define KPSSR1_OFFSET                        0x000000A4
+#define KPSSRN_OFFSET(reg_n)                 (KPSSR0_OFFSET + (4 * reg_n))
+#define KPIMR0_OFFSET                        0x000000B0
+#define KPIMR1_OFFSET                        0x000000B4
+#define KPICR0_OFFSET                        0x000000B8
+#define KPICR1_OFFSET                        0x000000BC
+#define KPICRN_OFFSET(reg_n)                 (KPICR0_OFFSET + (4 * reg_n))
+#define KPISR0_OFFSET                        0x000000C0
+#define KPISR1_OFFSET                        0x000000C4
+
+#define KPCR_STATUSFILTERTYPE_MAX 7
+#define KPCR_COLFILTERTYPE_MAX 7
+
+/* Macros to determine the row/column from a bit that is set in SSR0/1. */
+#define BIT_TO_ROW_SSRN(bit_nr, reg_n)  ((bit_nr >> 3) + (4 * reg_n))
+#define BIT_TO_COL(bit_nr)       (bit_nr % 8)
+
+/* Structure representing various run-time entities */
+struct bcm_kp {
+       void __iomem *base;
+       int irq;
+       struct clk *clk;
+       struct input_dev *input_dev;
+       unsigned long last_state[2];
+       unsigned int n_rows;
+       unsigned int n_cols;
+       u32 kpcr;
+       u32 kpior;
+       u32 kpemr;
+       u32 imr0_val;
+       u32 imr1_val;
+};
+
+/*
+ * Returns the keycode from the input device keymap given the row and
+ * column.
+ */
+static inline int bcm_kp_get_keycode(struct bcm_kp *kp, int row, int col)
+{
+       unsigned int row_shift = get_count_order(kp->n_cols);
+       unsigned short *keymap = kp->input_dev->keycode;
+
+       return keymap[MATRIX_SCAN_CODE(row, col, row_shift)];
+}
+
+static void bcm_kp_report_keys(struct bcm_kp *kp, int reg_num, int pull_mode)
+{
+       unsigned long state, change;
+       int bit_nr;
+       int key_press;
+       int row, col;
+       unsigned int keycode;
+
+       /* Clear interrupts */
+       writel(0xFFFFFFFF, kp->base + KPICRN_OFFSET(reg_num));
+
+       state = readl(kp->base + KPSSRN_OFFSET(reg_num));
+       change = kp->last_state[reg_num] ^ state;
+       kp->last_state[reg_num] = state;
+
+       for_each_set_bit(bit_nr, &change, BITS_PER_LONG) {
+               key_press = state & BIT(bit_nr);
+               /* The meaning of SSR register depends on pull mode. */
+               key_press = pull_mode ? !key_press : key_press;
+               row = BIT_TO_ROW_SSRN(bit_nr, reg_num);
+               col = BIT_TO_COL(bit_nr);
+               keycode = bcm_kp_get_keycode(kp, row, col);
+               input_report_key(kp->input_dev, keycode, key_press);
+       }
+}
+
+static irqreturn_t bcm_kp_isr_thread(int irq, void *dev_id)
+{
+       struct bcm_kp *kp = dev_id;
+       int pull_mode = (kp->kpcr >> KPCR_MODE_SHIFT) & KPCR_MODE_MASK;
+       int reg_num;
+
+       for (reg_num = 0; reg_num <= 1; reg_num++)
+               bcm_kp_report_keys(kp, reg_num, pull_mode);
+
+       input_sync(kp->input_dev);
+
+       return IRQ_HANDLED;
+}
+
+static int bcm_kp_start(struct bcm_kp *kp)
+{
+       int error;
+
+       error = clk_prepare_enable(kp->clk);
+       if (error)
+               return error;
+
+       writel(kp->kpior, kp->base + KPIOR_OFFSET);
+
+       writel(kp->imr0_val, kp->base + KPIMR0_OFFSET);
+       writel(kp->imr1_val, kp->base + KPIMR1_OFFSET);
+
+       writel(kp->kpemr, kp->base + KPEMR0_OFFSET);
+       writel(kp->kpemr, kp->base + KPEMR1_OFFSET);
+       writel(kp->kpemr, kp->base + KPEMR2_OFFSET);
+       writel(kp->kpemr, kp->base + KPEMR3_OFFSET);
+
+       writel(0xFFFFFFFF, kp->base + KPICR0_OFFSET);
+       writel(0xFFFFFFFF, kp->base + KPICR1_OFFSET);
+
+       kp->last_state[0] = readl(kp->base + KPSSR0_OFFSET);
+       kp->last_state[0] = readl(kp->base + KPSSR1_OFFSET);
+
+       writel(kp->kpcr | KPCR_ENABLE, kp->base + KPCR_OFFSET);
+
+       return 0;
+}
+
+static void bcm_kp_stop(const struct bcm_kp *kp)
+{
+       u32 val;
+
+       val = readl(kp->base + KPCR_OFFSET);
+       val &= ~KPCR_ENABLE;
+       writel(0, kp->base + KPCR_OFFSET);
+       writel(0, kp->base + KPIMR0_OFFSET);
+       writel(0, kp->base + KPIMR1_OFFSET);
+       writel(0xFFFFFFFF, kp->base + KPICR0_OFFSET);
+       writel(0xFFFFFFFF, kp->base + KPICR1_OFFSET);
+
+       clk_disable_unprepare(kp->clk);
+}
+
+static int bcm_kp_open(struct input_dev *dev)
+{
+       struct bcm_kp *kp = input_get_drvdata(dev);
+
+       return bcm_kp_start(kp);
+}
+
+static void bcm_kp_close(struct input_dev *dev)
+{
+       struct bcm_kp *kp = input_get_drvdata(dev);
+
+       bcm_kp_stop(kp);
+}
+
+static int bcm_kp_matrix_key_parse_dt(struct bcm_kp *kp)
+{
+       struct device *dev = kp->input_dev->dev.parent;
+       struct device_node *np = dev->of_node;
+       int error;
+       unsigned int dt_val;
+       unsigned int i;
+       unsigned int num_rows, col_mask, rows_set;
+
+       /* Initialize the KPCR Keypad Configuration Register */
+       kp->kpcr = KPCR_STATUSFILTERENABLE | KPCR_COLFILTERENABLE;
+
+       error = matrix_keypad_parse_of_params(dev, &kp->n_rows, &kp->n_cols);
+       if (error) {
+               dev_err(dev, "failed to parse kp params\n");
+               return error;
+       }
+       /* Set row width for the ASIC block. */
+       kp->kpcr |= (kp->n_rows - 1) << KPCR_ROWWIDTH_SHIFT;
+
+       /* Set column width for the ASIC block. */
+       kp->kpcr |= (kp->n_cols - 1) << KPCR_COLUMNWIDTH_SHIFT;
+
+       /* Configure the IMR registers */
+
+       /* 
+        * IMR registers contain interrupt enable bits for 8x8 matrix
+        * IMR0 register format: <row3> <row2> <row1> <row0>
+        * IMR1 register format: <row7> <row6> <row5> <row4>
+        */
+       col_mask = (1 << (kp->n_cols)) - 1;
+       num_rows = kp->n_rows;
+
+       /* Set column bits in rows 0 to 3 in IMR0 */
+       kp->imr0_val = col_mask;
+
+       rows_set = 1;
+       while ((--num_rows) && (rows_set++ < 4))
+               kp->imr0_val |= (kp->imr0_val << MAX_COLS);
+
+       /* Set column bits in rows 4 to 7 in IMR1 */
+       kp->imr1_val = 0;
+       if (num_rows) {
+               kp->imr1_val = col_mask;
+               while (--num_rows)
+                       kp->imr1_val |= (kp->imr1_val << MAX_COLS);
+       }
+
+       /* Initialize the KPEMR Keypress Edge Mode Registers */
+       /* Trigger on both edges */
+       kp->kpemr = 0;
+       for (i = 0; i <= 30; i = i + 2)
+               kp->kpemr |= (KPEMR_EDGETYPE_BOTH << i);
+
+       /*
+        * Obtain the Status filter debounce value and verify against the
+        * possible values specified in the DT binding.
+        */
+       of_property_read_u32(np, "status-debounce-filter-period",
+               &dt_val);
+       if (dt_val > KPCR_STATUSFILTERTYPE_MAX) {
+               dev_err(dev, "Invalid Status filter debounce value %d\n",
+                       dt_val);
+               return -EINVAL;
+       }
+       kp->kpcr |= dt_val << KPCR_STATUSFILTERTYPE_SHIFT;
+
+
+       /*
+        * Obtain the Column filter debounce value and verify against the
+        * possible values specified in the DT binding.
+        */
+       of_property_read_u32(np, "col-debounce-filter-period",
+               &dt_val);
+
+       if (dt_val > KPCR_COLFILTERTYPE_MAX) {
+               dev_err(dev, "Invalid Column filter debounce value %d\n",
+                       dt_val);
+               return -EINVAL;
+       }
+       kp->kpcr |= dt_val << KPCR_COLFILTERTYPE_SHIFT;
+
+       /*
+        * Determine between the row and column,
+        * which should be configured as output.
+        */
+       if (of_property_read_bool(np, "row-output-enabled")) {
+               /*
+               * Set RowOContrl or ColumnOContrl in KPIOR
+               * to the number of pins to drive as outputs
+               */
+               kp->kpior = (((1 << kp->n_rows) - 1) <<
+                               KPIOR_ROWOCONTRL_SHIFT);
+       } else {
+               kp->kpior = (((1 << kp->n_cols) - 1) <<
+                               KPIOR_COLUMNOCONTRL_SHIFT);
+       }
+
+       /*
+        * Determine if the scan pull up needs to be enabled
+        */
+       if (of_property_read_bool(np, "pull-up-enabled"))
+               kp->kpcr |= KPCR_MODE;
+
+       dev_dbg(dev, "n_rows=%d n_col=%d kpcr=%x kpior=%x kpemr=%x\n",
+               kp->n_rows, kp->n_cols,
+               kp->kpcr, kp->kpior, kp->kpemr);
+
+       return 0;
+}
+
+
+static int bcm_kp_probe(struct platform_device *pdev)
+{
+       struct bcm_kp *kp;
+       struct input_dev *input_dev;
+       struct resource *res;
+       int error;
+       bool repeat;
+
+       kp = devm_kzalloc(&pdev->dev, sizeof(*kp),
+                                  GFP_KERNEL);
+       if (!kp)
+               return -ENOMEM;
+
+       input_dev = devm_input_allocate_device(&pdev->dev);
+       if (!input_dev) {
+               dev_err(&pdev->dev, "failed to allocate the input device\n");
+               return -ENOMEM;
+       }
+
+       __set_bit(EV_KEY, input_dev->evbit);
+
+       repeat = !!of_get_property(pdev->dev.of_node, "autorepeat", NULL);
+       /* Enable auto repeat feature of Linux input subsystem */
+       if (repeat)
+               __set_bit(EV_REP, input_dev->evbit);
+
+       input_dev->name = pdev->name;
+       input_dev->phys = "keypad/input0";
+       input_dev->dev.parent = &pdev->dev;
+       input_dev->open = bcm_kp_open;
+       input_dev->close = bcm_kp_close;
+
+       input_dev->id.bustype = BUS_HOST;
+       input_dev->id.vendor = 0x0001;
+       input_dev->id.product = 0x0001;
+       input_dev->id.version = 0x0100;
+
+       input_set_drvdata(input_dev, kp);
+
+       kp->input_dev = input_dev;
+
+       platform_set_drvdata(pdev, kp);
+
+       error = bcm_kp_matrix_key_parse_dt(kp);
+       if (error)
+               return error;
+
+       error = matrix_keypad_build_keymap(NULL, NULL,
+                                          kp->n_rows,
+                                          kp->n_cols,
+                                          NULL, input_dev);
+       if (error) {
+               dev_err(&pdev->dev, "failed to build keymap\n");
+               return error;
+       }
+
+       /* Get the KEYPAD base address */
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!res) {
+               dev_err(&pdev->dev, "Missing keypad base address resource\n");
+               return -ENODEV;
+       }
+
+       kp->base = devm_ioremap_resource(&pdev->dev, res);
+       if (IS_ERR(kp->base))
+               return PTR_ERR(kp->base);
+
+       /* Enable clock */
+
+       kp->clk = devm_clk_get(&pdev->dev, "peri_clk");
+       if (IS_ERR(kp->clk)) {
+               dev_info(&pdev->dev,
+                       "No clock specified. Assuming it's enabled\n");
+       }
+       else {
+               unsigned int desired_rate;
+               long actual_rate;
+
+               error = of_property_read_u32(pdev->dev.of_node,
+                               "clock-frequency", &desired_rate);
+               if (error < 0)
+                       desired_rate = DEFAULT_CLK_HZ;
+
+               actual_rate = clk_round_rate(kp->clk, desired_rate);
+               if (actual_rate <= 0)
+                       return -EINVAL;
+
+               error = clk_set_rate(kp->clk, actual_rate);
+               if (error)
+                       return -EINVAL;
+
+               error = clk_prepare_enable(kp->clk);
+               if (error)
+                       return -EINVAL;
+       }
+
+       /* Put the kp into a known sane state */
+       bcm_kp_stop(kp);
+
+       kp->irq = platform_get_irq(pdev, 0);
+       if (kp->irq < 0) {
+               dev_err(&pdev->dev, "no IRQ specified\n");
+               return -EINVAL;
+       }
+
+       error = devm_request_threaded_irq(&pdev->dev, kp->irq, NULL,
+               bcm_kp_isr_thread,
+               IRQF_ONESHOT, pdev->name, kp);
+       if (error) {
+               dev_err(&pdev->dev, "failed to request IRQ\n");
+               return error;
+       }
+
+       error = input_register_device(input_dev);
+       if (error) {
+               dev_err(&pdev->dev, "failed to register input device\n");
+               return error;
+       }
+
+       return 0;
+}
+
+static const struct of_device_id bcm_kp_of_match[] = {
+       { .compatible = "brcm,bcm-keypad" },
+       { },
+};
+MODULE_DEVICE_TABLE(of, bcm_kp_of_match);
+
+static struct platform_driver bcm_kp_device_driver = {
+       .probe          = bcm_kp_probe,
+       .driver         = {
+               .name   = "bcm-keypad",
+               .of_match_table = of_match_ptr(bcm_kp_of_match),
+       }
+};
+
+module_platform_driver(bcm_kp_device_driver);
+
+MODULE_AUTHOR("Broadcom Corporation");
+MODULE_DESCRIPTION("BCM Keypad Driver");
+MODULE_LICENSE("GPL v2");
-- 
2.3.0

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