/* * Copyright (C) 2009-2014 Freescale Semiconductor, Inc. All Rights Reserved. * * SPDX-License-Identifier: GPL-2.0+ */ /*! * @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 #include #include #include #include #include /* * * Module header file * */ #include /*! * 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; }