linux/drivers/input/keyboard/bcm-keypad.c

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/*
* 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/bitops.h>
#include <linux/clk.h>
#include <linux/gfp.h>
#include <linux/io.h>
#include <linux/input.h>
#include <linux/input/matrix_keypad.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/stddef.h>
#include <linux/types.h>
#define DEFAULT_CLK_HZ 31250
#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 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;
if (kp->clk) {
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);
if (kp->clk)
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_properties(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 += 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;
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);
/* Enable auto repeat feature of Linux input subsystem */
if (of_property_read_bool(pdev->dev.of_node, "autorepeat"))
__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;
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)) {
error = PTR_ERR(kp->clk);
if (error != -ENOENT) {
if (error != -EPROBE_DEFER)
dev_err(&pdev->dev, "Failed to get clock\n");
return error;
}
dev_dbg(&pdev->dev,
"No clock specified. Assuming it's enabled\n");
kp->clk = NULL;
} 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 error;
error = clk_prepare_enable(kp->clk);
if (error)
return error;
}
/* 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");