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linux-zen-desktop/drivers/input/keyboard/twl4030_keypad.c

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2023-08-30 17:31:07 +02:00
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* twl4030_keypad.c - driver for 8x8 keypad controller in twl4030 chips
*
* Copyright (C) 2007 Texas Instruments, Inc.
* Copyright (C) 2008 Nokia Corporation
*
* Code re-written for 2430SDP by:
* Syed Mohammed Khasim <x0khasim@ti.com>
*
* Initial Code:
* Manjunatha G K <manjugk@ti.com>
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/platform_device.h>
#include <linux/mfd/twl.h>
#include <linux/slab.h>
#include <linux/of.h>
/*
* The TWL4030 family chips include a keypad controller that supports
* up to an 8x8 switch matrix. The controller can issue system wakeup
* events, since it uses only the always-on 32KiHz oscillator, and has
* an internal state machine that decodes pressed keys, including
* multi-key combinations.
*
* This driver lets boards define what keycodes they wish to report for
* which scancodes, as part of the "struct twl4030_keypad_data" used in
* the probe() routine.
*
* See the TPS65950 documentation; that's the general availability
* version of the TWL5030 second generation part.
*/
#define TWL4030_MAX_ROWS 8 /* TWL4030 hard limit */
#define TWL4030_MAX_COLS 8
/*
* Note that we add space for an extra column so that we can handle
* row lines connected to the gnd (see twl4030_col_xlate()).
*/
#define TWL4030_ROW_SHIFT 4
#define TWL4030_KEYMAP_SIZE (TWL4030_MAX_ROWS << TWL4030_ROW_SHIFT)
struct twl4030_keypad {
unsigned short keymap[TWL4030_KEYMAP_SIZE];
u16 kp_state[TWL4030_MAX_ROWS];
bool autorepeat;
unsigned int n_rows;
unsigned int n_cols;
int irq;
struct device *dbg_dev;
struct input_dev *input;
};
/*----------------------------------------------------------------------*/
/* arbitrary prescaler value 0..7 */
#define PTV_PRESCALER 4
/* Register Offsets */
#define KEYP_CTRL 0x00
#define KEYP_DEB 0x01
#define KEYP_LONG_KEY 0x02
#define KEYP_LK_PTV 0x03
#define KEYP_TIMEOUT_L 0x04
#define KEYP_TIMEOUT_H 0x05
#define KEYP_KBC 0x06
#define KEYP_KBR 0x07
#define KEYP_SMS 0x08
#define KEYP_FULL_CODE_7_0 0x09 /* row 0 column status */
#define KEYP_FULL_CODE_15_8 0x0a /* ... row 1 ... */
#define KEYP_FULL_CODE_23_16 0x0b
#define KEYP_FULL_CODE_31_24 0x0c
#define KEYP_FULL_CODE_39_32 0x0d
#define KEYP_FULL_CODE_47_40 0x0e
#define KEYP_FULL_CODE_55_48 0x0f
#define KEYP_FULL_CODE_63_56 0x10
#define KEYP_ISR1 0x11
#define KEYP_IMR1 0x12
#define KEYP_ISR2 0x13
#define KEYP_IMR2 0x14
#define KEYP_SIR 0x15
#define KEYP_EDR 0x16 /* edge triggers */
#define KEYP_SIH_CTRL 0x17
/* KEYP_CTRL_REG Fields */
#define KEYP_CTRL_SOFT_NRST BIT(0)
#define KEYP_CTRL_SOFTMODEN BIT(1)
#define KEYP_CTRL_LK_EN BIT(2)
#define KEYP_CTRL_TOE_EN BIT(3)
#define KEYP_CTRL_TOLE_EN BIT(4)
#define KEYP_CTRL_RP_EN BIT(5)
#define KEYP_CTRL_KBD_ON BIT(6)
/* KEYP_DEB, KEYP_LONG_KEY, KEYP_TIMEOUT_x*/
#define KEYP_PERIOD_US(t, prescale) ((t) / (31 << ((prescale) + 1)) - 1)
/* KEYP_LK_PTV_REG Fields */
#define KEYP_LK_PTV_PTV_SHIFT 5
/* KEYP_{IMR,ISR,SIR} Fields */
#define KEYP_IMR1_MIS BIT(3)
#define KEYP_IMR1_TO BIT(2)
#define KEYP_IMR1_LK BIT(1)
#define KEYP_IMR1_KP BIT(0)
/* KEYP_EDR Fields */
#define KEYP_EDR_KP_FALLING 0x01
#define KEYP_EDR_KP_RISING 0x02
#define KEYP_EDR_KP_BOTH 0x03
#define KEYP_EDR_LK_FALLING 0x04
#define KEYP_EDR_LK_RISING 0x08
#define KEYP_EDR_TO_FALLING 0x10
#define KEYP_EDR_TO_RISING 0x20
#define KEYP_EDR_MIS_FALLING 0x40
#define KEYP_EDR_MIS_RISING 0x80
/*----------------------------------------------------------------------*/
static int twl4030_kpread(struct twl4030_keypad *kp,
u8 *data, u32 reg, u8 num_bytes)
{
int ret = twl_i2c_read(TWL4030_MODULE_KEYPAD, data, reg, num_bytes);
if (ret < 0)
dev_warn(kp->dbg_dev,
"Couldn't read TWL4030: %X - ret %d[%x]\n",
reg, ret, ret);
return ret;
}
static int twl4030_kpwrite_u8(struct twl4030_keypad *kp, u8 data, u32 reg)
{
int ret = twl_i2c_write_u8(TWL4030_MODULE_KEYPAD, data, reg);
if (ret < 0)
dev_warn(kp->dbg_dev,
"Could not write TWL4030: %X - ret %d[%x]\n",
reg, ret, ret);
return ret;
}
static inline u16 twl4030_col_xlate(struct twl4030_keypad *kp, u8 col)
{
/*
* If all bits in a row are active for all columns then
* we have that row line connected to gnd. Mark this
* key on as if it was on matrix position n_cols (i.e.
* one higher than the size of the matrix).
*/
if (col == 0xFF)
return 1 << kp->n_cols;
else
return col & ((1 << kp->n_cols) - 1);
}
static int twl4030_read_kp_matrix_state(struct twl4030_keypad *kp, u16 *state)
{
u8 new_state[TWL4030_MAX_ROWS];
int row;
int ret = twl4030_kpread(kp, new_state,
KEYP_FULL_CODE_7_0, kp->n_rows);
if (ret >= 0)
for (row = 0; row < kp->n_rows; row++)
state[row] = twl4030_col_xlate(kp, new_state[row]);
return ret;
}
static bool twl4030_is_in_ghost_state(struct twl4030_keypad *kp, u16 *key_state)
{
int i;
u16 check = 0;
for (i = 0; i < kp->n_rows; i++) {
u16 col = key_state[i];
if ((col & check) && hweight16(col) > 1)
return true;
check |= col;
}
return false;
}
static void twl4030_kp_scan(struct twl4030_keypad *kp, bool release_all)
{
struct input_dev *input = kp->input;
u16 new_state[TWL4030_MAX_ROWS];
int col, row;
if (release_all) {
memset(new_state, 0, sizeof(new_state));
} else {
/* check for any changes */
int ret = twl4030_read_kp_matrix_state(kp, new_state);
if (ret < 0) /* panic ... */
return;
if (twl4030_is_in_ghost_state(kp, new_state))
return;
}
/* check for changes and print those */
for (row = 0; row < kp->n_rows; row++) {
int changed = new_state[row] ^ kp->kp_state[row];
if (!changed)
continue;
/* Extra column handles "all gnd" rows */
for (col = 0; col < kp->n_cols + 1; col++) {
int code;
if (!(changed & (1 << col)))
continue;
dev_dbg(kp->dbg_dev, "key [%d:%d] %s\n", row, col,
(new_state[row] & (1 << col)) ?
"press" : "release");
code = MATRIX_SCAN_CODE(row, col, TWL4030_ROW_SHIFT);
input_event(input, EV_MSC, MSC_SCAN, code);
input_report_key(input, kp->keymap[code],
new_state[row] & (1 << col));
}
kp->kp_state[row] = new_state[row];
}
input_sync(input);
}
/*
* Keypad interrupt handler
*/
static irqreturn_t do_kp_irq(int irq, void *_kp)
{
struct twl4030_keypad *kp = _kp;
u8 reg;
int ret;
/* Read & Clear TWL4030 pending interrupt */
ret = twl4030_kpread(kp, &reg, KEYP_ISR1, 1);
/*
* Release all keys if I2C has gone bad or
* the KEYP has gone to idle state.
*/
if (ret >= 0 && (reg & KEYP_IMR1_KP))
twl4030_kp_scan(kp, false);
else
twl4030_kp_scan(kp, true);
return IRQ_HANDLED;
}
static int twl4030_kp_program(struct twl4030_keypad *kp)
{
u8 reg;
int i;
/* Enable controller, with hardware decoding but not autorepeat */
reg = KEYP_CTRL_SOFT_NRST | KEYP_CTRL_SOFTMODEN
| KEYP_CTRL_TOE_EN | KEYP_CTRL_KBD_ON;
if (twl4030_kpwrite_u8(kp, reg, KEYP_CTRL) < 0)
return -EIO;
/*
* NOTE: we could use sih_setup() here to package keypad
* event sources as four different IRQs ... but we don't.
*/
/* Enable TO rising and KP rising and falling edge detection */
reg = KEYP_EDR_KP_BOTH | KEYP_EDR_TO_RISING;
if (twl4030_kpwrite_u8(kp, reg, KEYP_EDR) < 0)
return -EIO;
/* Set PTV prescaler Field */
reg = (PTV_PRESCALER << KEYP_LK_PTV_PTV_SHIFT);
if (twl4030_kpwrite_u8(kp, reg, KEYP_LK_PTV) < 0)
return -EIO;
/* Set key debounce time to 20 ms */
i = KEYP_PERIOD_US(20000, PTV_PRESCALER);
if (twl4030_kpwrite_u8(kp, i, KEYP_DEB) < 0)
return -EIO;
/* Set timeout period to 200 ms */
i = KEYP_PERIOD_US(200000, PTV_PRESCALER);
if (twl4030_kpwrite_u8(kp, (i & 0xFF), KEYP_TIMEOUT_L) < 0)
return -EIO;
if (twl4030_kpwrite_u8(kp, (i >> 8), KEYP_TIMEOUT_H) < 0)
return -EIO;
/*
* Enable Clear-on-Read; disable remembering events that fire
* after the IRQ but before our handler acks (reads) them.
*/
reg = TWL4030_SIH_CTRL_COR_MASK | TWL4030_SIH_CTRL_PENDDIS_MASK;
if (twl4030_kpwrite_u8(kp, reg, KEYP_SIH_CTRL) < 0)
return -EIO;
/* initialize key state; irqs update it from here on */
if (twl4030_read_kp_matrix_state(kp, kp->kp_state) < 0)
return -EIO;
return 0;
}
/*
* Registers keypad device with input subsystem
* and configures TWL4030 keypad registers
*/
static int twl4030_kp_probe(struct platform_device *pdev)
{
struct twl4030_keypad_data *pdata = dev_get_platdata(&pdev->dev);
const struct matrix_keymap_data *keymap_data = NULL;
struct twl4030_keypad *kp;
struct input_dev *input;
u8 reg;
int error;
kp = devm_kzalloc(&pdev->dev, sizeof(*kp), GFP_KERNEL);
if (!kp)
return -ENOMEM;
input = devm_input_allocate_device(&pdev->dev);
if (!input)
return -ENOMEM;
/* get the debug device */
kp->dbg_dev = &pdev->dev;
kp->input = input;
/* setup input device */
input->name = "TWL4030 Keypad";
input->phys = "twl4030_keypad/input0";
input->id.bustype = BUS_HOST;
input->id.vendor = 0x0001;
input->id.product = 0x0001;
input->id.version = 0x0003;
if (pdata) {
if (!pdata->rows || !pdata->cols || !pdata->keymap_data) {
dev_err(&pdev->dev, "Missing platform_data\n");
return -EINVAL;
}
kp->n_rows = pdata->rows;
kp->n_cols = pdata->cols;
kp->autorepeat = pdata->rep;
keymap_data = pdata->keymap_data;
} else {
error = matrix_keypad_parse_properties(&pdev->dev, &kp->n_rows,
&kp->n_cols);
if (error)
return error;
kp->autorepeat = true;
}
if (kp->n_rows > TWL4030_MAX_ROWS || kp->n_cols > TWL4030_MAX_COLS) {
dev_err(&pdev->dev,
"Invalid rows/cols amount specified in platform/devicetree data\n");
return -EINVAL;
}
kp->irq = platform_get_irq(pdev, 0);
if (kp->irq < 0)
return kp->irq;
error = matrix_keypad_build_keymap(keymap_data, NULL,
TWL4030_MAX_ROWS,
1 << TWL4030_ROW_SHIFT,
kp->keymap, input);
if (error) {
dev_err(kp->dbg_dev, "Failed to build keymap\n");
return error;
}
input_set_capability(input, EV_MSC, MSC_SCAN);
/* Enable auto repeat feature of Linux input subsystem */
if (kp->autorepeat)
__set_bit(EV_REP, input->evbit);
error = input_register_device(input);
if (error) {
dev_err(kp->dbg_dev,
"Unable to register twl4030 keypad device\n");
return error;
}
error = twl4030_kp_program(kp);
if (error)
return error;
/*
* This ISR will always execute in kernel thread context because of
* the need to access the TWL4030 over the I2C bus.
*
* NOTE: we assume this host is wired to TWL4040 INT1, not INT2 ...
*/
error = devm_request_threaded_irq(&pdev->dev, kp->irq, NULL, do_kp_irq,
0, pdev->name, kp);
if (error) {
dev_info(kp->dbg_dev, "request_irq failed for irq no=%d: %d\n",
kp->irq, error);
return error;
}
/* Enable KP and TO interrupts now. */
reg = (u8) ~(KEYP_IMR1_KP | KEYP_IMR1_TO);
if (twl4030_kpwrite_u8(kp, reg, KEYP_IMR1)) {
/* mask all events - we don't care about the result */
(void) twl4030_kpwrite_u8(kp, 0xff, KEYP_IMR1);
return -EIO;
}
return 0;
}
#ifdef CONFIG_OF
static const struct of_device_id twl4030_keypad_dt_match_table[] = {
{ .compatible = "ti,twl4030-keypad" },
{},
};
MODULE_DEVICE_TABLE(of, twl4030_keypad_dt_match_table);
#endif
/*
* NOTE: twl4030 are multi-function devices connected via I2C.
* So this device is a child of an I2C parent, thus it needs to
* support unplug/replug (which most platform devices don't).
*/
static struct platform_driver twl4030_kp_driver = {
.probe = twl4030_kp_probe,
.driver = {
.name = "twl4030_keypad",
.of_match_table = of_match_ptr(twl4030_keypad_dt_match_table),
},
};
module_platform_driver(twl4030_kp_driver);
MODULE_AUTHOR("Texas Instruments");
MODULE_DESCRIPTION("TWL4030 Keypad Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:twl4030_keypad");