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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2009-2014 Freescale Semiconductor, Inc. All Rights Reserved.
*
*/
/*!
* @file mxc_keyb.c
*
* @brief Driver for the Freescale Semiconductor MXC keypad port.
*
* The keypad driver is designed as a standard Input driver which interacts
* with low level keypad port hardware. Upon opening, the Keypad driver
* initializes the keypad port. When the keypad interrupt happens the driver
* calles keypad polling timer and scans the keypad matrix for key
* press/release. If all key press/release happened it comes out of timer and
* waits for key press interrupt. The scancode for key press and release events
* are passed to Input subsytem.
*
* @ingroup keypad
*/
#include <asm/io.h>
#include <common.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <asm/mach-imx/mxc_key_defs.h>
#include <malloc.h>
/*
* * Module header file
* */
#include <mxc_keyb.h>
/*!
* Comment KPP_DEBUG to disable debug messages
*/
#undef KPP_DEBUG
#ifdef KPP_DEBUG
#define KPP_PRINTF(fmt, args...) printf(fmt , ##args)
static void mxc_kpp_dump_regs()
{
unsigned short t1, t2, t3;
t1 = __raw_readw(KPCR);
t2 = __raw_readw(KPSR);
t3 = __raw_readw(KDDR);
/*
KPP_PRINTF("KPCR=0x%04x, KPSR=0x%04x, KDDR=0x%04x\n",
t1, t2, t3);
*/
}
#else
#define KPP_PRINTF(fmt, args...)
#endif
static u16 mxc_key_mapping[] = CONFIG_MXC_KEYMAPPING;
/*!
* This structure holds the keypad private data structure.
*/
static struct keypad_priv kpp_dev;
/*! Indicates if the key pad device is enabled. */
/*! This static variable indicates whether a key event is pressed/released. */
static unsigned short KPress;
/*! cur_rcmap and prev_rcmap array is used to detect key press and release. */
static unsigned short *cur_rcmap; /* max 64 bits (8x8 matrix) */
static unsigned short *prev_rcmap;
/*!
* Debounce polling period(10ms) in system ticks.
*/
/*static unsigned short KScanRate = (10 * CONFIG_SYS_HZ) / 1000;*/
/*!
* These arrays are used to store press and release scancodes.
*/
static short **press_scancode;
static short **release_scancode;
static const unsigned short *mxckpd_keycodes;
static unsigned short mxckpd_keycodes_size;
/*!
* This function is called to scan the keypad matrix to find out the key press
* and key release events. Make scancode and break scancode are generated for
* key press and key release events.
*
* The following scanning sequence are done for
* keypad row and column scanning,
* -# Write 1's to KPDR[15:8], setting column data to 1's
* -# Configure columns as totem pole outputs(for quick discharging of keypad
* capacitance)
* -# Configure columns as open-drain
* -# Write a single column to 0, others to 1.
* -# Sample row inputs and save data. Multiple key presses can be detected on
* a single column.
* -# Repeat steps the above steps for remaining columns.
* -# Return all columns to 0 in preparation for standby mode.
* -# Clear KPKD and KPKR status bit(s) by writing to a 1,
* Set the KPKR synchronizer chain by writing "1" to KRSS register,
* Clear the KPKD synchronizer chain by writing "1" to KDSC register
*
* @result Number of key pressed/released.
*/
static int mxc_kpp_scan_matrix(void)
{
unsigned short reg_val;
int col, row;
short scancode = 0;
int keycnt = 0; /* How many keys are still pressed */
/*
* wmb() linux kernel function which guarantees orderings in write
* operations
*/
/* wmb(); */
/* save cur keypad matrix to prev */
memcpy(prev_rcmap, cur_rcmap, kpp_dev.kpp_rows * sizeof(prev_rcmap[0]));
memset(cur_rcmap, 0, kpp_dev.kpp_rows * sizeof(cur_rcmap[0]));
/*1. Disable both (depress and release) keypad interrupts.*/
/* KDIE has been disabled in mxc_kpp_getc before calling scan matrix.
* KRIE is always disabled in this driver.
*/
for (col = 0; col < kpp_dev.kpp_cols; col++) { /* Col */
/* 2. Write 1.s to KPDR[15:8] setting column data to 1.s */
reg_val = __raw_readw(KPDR);
reg_val |= 0xff00;
__raw_writew(reg_val, KPDR);
/*
* 3. Configure columns as totem pole outputs(for quick
* discharging of keypad capacitance)
*/
reg_val = __raw_readw(KPCR);
reg_val &= 0x00ff;
__raw_writew(reg_val, KPCR);
udelay(2);
#ifdef KPP_DEBUG
mxc_kpp_dump_regs();
#endif
/*
* 4. Configure columns as open-drain
*/
reg_val = __raw_readw(KPCR);
reg_val |= ((1 << kpp_dev.kpp_cols) - 1) << 8;
__raw_writew(reg_val, KPCR);
/*
* 5. Write a single column to 0, others to 1.
* 6. Sample row inputs and save data. Multiple key presses
* can be detected on a single column.
* 7. Repeat steps 2 - 6 for remaining columns.
*/
/* Col bit starts at 8th bit in KPDR */
reg_val = __raw_readw(KPDR);
reg_val &= ~(1 << (8 + col));
__raw_writew(reg_val, KPDR);
/* Delay added to avoid propagating the 0 from column to row
* when scanning. */
udelay(5);
#ifdef KPP_DEBUG
mxc_kpp_dump_regs();
#endif
/* Read row input */
reg_val = __raw_readw(KPDR);
for (row = 0; row < kpp_dev.kpp_rows; row++) { /* sample row */
if (TEST_BIT(reg_val, row) == 0) {
cur_rcmap[row] = BITSET(cur_rcmap[row], col);
keycnt++;
}
}
}
/*
* 8. Return all columns to 0 in preparation for standby mode.
* 9. Clear KPKD and KPKR status bit(s) by writing to a .1.,
* set the KPKR synchronizer chain by writing "1" to KRSS register,
* clear the KPKD synchronizer chain by writing "1" to KDSC register
*/
reg_val = 0x00;
__raw_writew(reg_val, KPDR);
reg_val = __raw_readw(KPDR);
reg_val = __raw_readw(KPSR);
reg_val |= KBD_STAT_KPKD | KBD_STAT_KPKR | KBD_STAT_KRSS |
KBD_STAT_KDSC;
__raw_writew(reg_val, KPSR);
#ifdef KPP_DEBUG
mxc_kpp_dump_regs();
#endif
/* Check key press status change */
/*
* prev_rcmap array will contain the previous status of the keypad
* matrix. cur_rcmap array will contains the present status of the
* keypad matrix. If a bit is set in the array, that (row, col) bit is
* pressed, else it is not pressed.
*
* XORing these two variables will give us the change in bit for
* particular row and column. If a bit is set in XOR output, then that
* (row, col) has a change of status from the previous state. From
* the diff variable the key press and key release of row and column
* are found out.
*
* If the key press is determined then scancode for key pressed
* can be generated using the following statement:
* scancode = ((row * 8) + col);
*
* If the key release is determined then scancode for key release
* can be generated using the following statement:
* scancode = ((row * 8) + col) + MXC_KEYRELEASE;
*/
for (row = 0; row < kpp_dev.kpp_rows; row++) {
unsigned char diff;
/*
* Calculate the change in the keypad row status
*/
diff = prev_rcmap[row] ^ cur_rcmap[row];
for (col = 0; col < kpp_dev.kpp_cols; col++) {
if ((diff >> col) & 0x1) {
/* There is a status change on col */
if ((prev_rcmap[row] & BITSET(0, col)) == 0) {
/*
* Previous state is 0, so now
* a key is pressed
*/
scancode =
((row * kpp_dev.kpp_cols) +
col);
KPress = 1;
kpp_dev.iKeyState = KStateUp;
KPP_PRINTF("Press (%d, %d) scan=%d "
"Kpress=%d\n",
row, col, scancode, KPress);
press_scancode[row][col] =
(short)scancode;
} else {
/*
* Previous state is not 0, so
* now a key is released
*/
scancode =
(row * kpp_dev.kpp_cols) +
col + MXC_KEYRELEASE;
KPress = 0;
kpp_dev.iKeyState = KStateDown;
KPP_PRINTF
("Release (%d, %d) scan=%d Kpress=%d\n",
row, col, scancode, KPress);
release_scancode[row][col] =
(short)scancode;
keycnt++;
}
}
}
}
return keycnt;
}
static int mxc_kpp_reset(void)
{
unsigned short reg_val;
int i;
/*
* Stop scanning and wait for interrupt.
* Enable press interrupt and disable release interrupt.
*/
__raw_writew(0x00FF, KPDR);
reg_val = __raw_readw(KPSR);
reg_val |= (KBD_STAT_KPKR | KBD_STAT_KPKD);
reg_val |= KBD_STAT_KRSS | KBD_STAT_KDSC;
__raw_writew(reg_val, KPSR);
reg_val |= KBD_STAT_KDIE;
reg_val &= ~KBD_STAT_KRIE;
__raw_writew(reg_val, KPSR);
#ifdef KPP_DEBUG
mxc_kpp_dump_regs();
#endif
/*
* No more keys pressed... make sure unwanted key codes are
* not given upstairs
*/
for (i = 0; i < kpp_dev.kpp_rows; i++) {
memset(press_scancode[i], -1,
sizeof(press_scancode[0][0]) * kpp_dev.kpp_cols);
memset(release_scancode[i], -1,
sizeof(release_scancode[0][0]) *
kpp_dev.kpp_cols);
}
return 0;
}
int mxc_kpp_getc(struct kpp_key_info **key_info)
{
int col, row;
int key_cnt;
unsigned short reg_val;
short scancode = 0;
int index = 0;
struct kpp_key_info *keyi;
reg_val = __raw_readw(KPSR);
if (reg_val & KBD_STAT_KPKD) {
/*
* Disable key press(KDIE status bit) interrupt
*/
reg_val &= ~KBD_STAT_KDIE;
__raw_writew(reg_val, KPSR);
#ifdef KPP_DEBUG
mxc_kpp_dump_regs();
#endif
key_cnt = mxc_kpp_scan_matrix();
} else {
return 0;
}
if (key_cnt <= 0)
return 0;
*key_info = keyi =
(struct kpp_key_info *)malloc
(sizeof(struct kpp_key_info) * key_cnt);
/*
* This switch case statement is the
* implementation of state machine of debounc
* logic for key press/release.
* The explaination of state machine is as
* follows:
*
* KStateUp State:
* This is in intial state of the state machine
* this state it checks for any key presses.
* The key press can be checked using the
* variable KPress. If KPress is set, then key
* press is identified and switches the to
* KStateFirstDown state for key press to
* debounce.
*
* KStateFirstDown:
* After debounce delay(10ms), if the KPress is
* still set then pass scancode generated to
* input device and change the state to
* KStateDown, else key press debounce is not
* satisfied so change the state to KStateUp.
*
* KStateDown:
* In this state it checks for any key release.
* If KPress variable is cleared, then key
* release is indicated and so, switch the
* state to KStateFirstUp else to state
* KStateDown.
*
* KStateFirstUp:
* After debounce delay(10ms), if the KPress is
* still reset then pass the key release
* scancode to input device and change
* the state to KStateUp else key release is
* not satisfied so change the state to
* KStateDown.
*/
for (row = 0; row < kpp_dev.kpp_rows; row++) {
for (col = 0; col < kpp_dev.kpp_cols; col++) {
if ((press_scancode[row][col] != -1)) {
/* Still Down, so add scancode */
scancode =
press_scancode[row][col];
keyi[index].val = mxckpd_keycodes[scancode];
keyi[index++].evt = KDepress;
KPP_PRINTF("KStateFirstDown: scan=%d val=%d\n",
scancode, mxckpd_keycodes[scancode]);
if (index >= key_cnt)
goto key_detect;
kpp_dev.iKeyState = KStateDown;
press_scancode[row][col] = -1;
}
}
}
for (row = 0; row < kpp_dev.kpp_rows; row++) {
for (col = 0; col < kpp_dev.kpp_cols; col++) {
if ((release_scancode[row][col] != -1)) {
scancode =
release_scancode[row][col];
scancode =
scancode - MXC_KEYRELEASE;
keyi[index].val = mxckpd_keycodes[scancode];
keyi[index++].evt = KRelease;
KPP_PRINTF("KStateFirstUp: scan=%d val=%d\n",
scancode, mxckpd_keycodes[scancode]);
if (index >= key_cnt)
goto key_detect;
kpp_dev.iKeyState = KStateUp;
release_scancode[row][col] = -1;
}
}
}
key_detect:
mxc_kpp_reset();
return key_cnt;
}
/*!
* This function is called to free the allocated memory for local arrays
*/
static void mxc_kpp_free_allocated(void)
{
int i;
if (press_scancode) {
for (i = 0; i < kpp_dev.kpp_rows; i++) {
if (press_scancode[i])
free(press_scancode[i]);
}
free(press_scancode);
}
if (release_scancode) {
for (i = 0; i < kpp_dev.kpp_rows; i++) {
if (release_scancode[i])
free(release_scancode[i]);
}
free(release_scancode);
}
if (cur_rcmap)
free(cur_rcmap);
if (prev_rcmap)
free(prev_rcmap);
}
/*!
* This function is called during the driver binding process.
*
* @param pdev the device structure used to store device specific
* information that is used by the suspend, resume and remove
* functions.
*
* @return The function returns 0 on successful registration. Otherwise returns
* specific error code.
*/
int mxc_kpp_init(void)
{
int i;
int retval;
unsigned int reg_val;
kpp_dev.kpp_cols = CONFIG_MXC_KPD_COLMAX;
kpp_dev.kpp_rows = CONFIG_MXC_KPD_ROWMAX;
/* clock and IOMUX configuration for keypad */
setup_mxc_kpd();
/* Configure keypad */
/* Enable number of rows in keypad (KPCR[7:0])
* Configure keypad columns as open-drain (KPCR[15:8])
*
* Configure the rows/cols in KPP
* LSB nibble in KPP is for 8 rows
* MSB nibble in KPP is for 8 cols
*/
reg_val = __raw_readw(KPCR);
reg_val |= (1 << kpp_dev.kpp_rows) - 1; /* LSB */
reg_val |= ((1 << kpp_dev.kpp_cols) - 1) << 8; /* MSB */
__raw_writew(reg_val, KPCR);
/* Write 0's to KPDR[15:8] */
reg_val = __raw_readw(KPDR);
reg_val &= 0x00ff;
__raw_writew(reg_val, KPDR);
/* Configure columns as output,
* rows as input (KDDR[15:0]) */
reg_val = __raw_readw(KDDR);
reg_val |= 0xff00;
reg_val &= 0xff00;
__raw_writew(reg_val, KDDR);
/* Clear the KPKD Status Flag
* and Synchronizer chain. */
reg_val = __raw_readw(KPSR);
reg_val &= ~(KBD_STAT_KPKR | KBD_STAT_KPKD);
reg_val |= KBD_STAT_KPKD;
reg_val |= KBD_STAT_KRSS | KBD_STAT_KDSC;
__raw_writew(reg_val, KPSR);
/* Set the KDIE control bit, and clear the KRIE
* control bit (avoid false release events). */
reg_val |= KBD_STAT_KDIE;
reg_val &= ~KBD_STAT_KRIE;
__raw_writew(reg_val, KPSR);
#ifdef KPP_DEBUG
mxc_kpp_dump_regs();
#endif
mxckpd_keycodes = mxc_key_mapping;
mxckpd_keycodes_size = kpp_dev.kpp_cols * kpp_dev.kpp_rows;
if ((mxckpd_keycodes == (void *)0)
|| (mxckpd_keycodes_size == 0)) {
retval = -ENODEV;
goto err;
}
/* allocate required memory */
press_scancode = (short **)malloc(kpp_dev.kpp_rows * sizeof(press_scancode[0]));
release_scancode = (short **)malloc(kpp_dev.kpp_rows * sizeof(release_scancode[0]));
if (!press_scancode || !release_scancode) {
retval = -ENOMEM;
goto err;
}
for (i = 0; i < kpp_dev.kpp_rows; i++) {
press_scancode[i] = (short *)malloc(kpp_dev.kpp_cols
* sizeof(press_scancode[0][0]));
release_scancode[i] =
(short *)malloc(kpp_dev.kpp_cols * sizeof(release_scancode[0][0]));
if (!press_scancode[i] || !release_scancode[i]) {
retval = -ENOMEM;
goto err;
}
}
cur_rcmap =
(unsigned short *)malloc(kpp_dev.kpp_rows * sizeof(cur_rcmap[0]));
prev_rcmap =
(unsigned short *)malloc(kpp_dev.kpp_rows * sizeof(prev_rcmap[0]));
if (!cur_rcmap || !prev_rcmap) {
retval = -ENOMEM;
goto err;
}
for (i = 0; i < kpp_dev.kpp_rows; i++) {
memset(press_scancode[i], -1,
sizeof(press_scancode[0][0]) * kpp_dev.kpp_cols);
memset(release_scancode[i], -1,
sizeof(release_scancode[0][0]) * kpp_dev.kpp_cols);
}
memset(cur_rcmap, 0, kpp_dev.kpp_rows * sizeof(cur_rcmap[0]));
memset(prev_rcmap, 0, kpp_dev.kpp_rows * sizeof(prev_rcmap[0]));
return 0;
err:
mxc_kpp_free_allocated();
return retval;
}