1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * (C) Copyright 2011 4 * Holger Brunck, Keymile GmbH Hannover, holger.brunck@keymile.com 5 */ 6 7 #include <common.h> 8 #include <i2c.h> 9 #include <asm/io.h> 10 #include <linux/ctype.h> 11 #include "../common/common.h" 12 13 static void i2c_write_start_seq(void) 14 { 15 struct fsl_i2c_base *base; 16 base = (struct fsl_i2c_base *)(CONFIG_SYS_IMMR + 17 CONFIG_SYS_I2C_OFFSET); 18 udelay(DELAY_ABORT_SEQ); 19 out_8(&base->cr, (I2C_CR_MEN | I2C_CR_MSTA)); 20 udelay(DELAY_ABORT_SEQ); 21 out_8(&base->cr, (I2C_CR_MEN)); 22 } 23 24 int i2c_make_abort(void) 25 { 26 struct fsl_i2c_base *base; 27 base = (struct fsl_i2c_base *)(CONFIG_SYS_IMMR + 28 CONFIG_SYS_I2C_OFFSET); 29 uchar last; 30 int nbr_read = 0; 31 int i = 0; 32 int ret = 0; 33 34 /* wait after each operation to finsh with a delay */ 35 out_8(&base->cr, (I2C_CR_MSTA)); 36 udelay(DELAY_ABORT_SEQ); 37 out_8(&base->cr, (I2C_CR_MEN | I2C_CR_MSTA)); 38 udelay(DELAY_ABORT_SEQ); 39 in_8(&base->dr); 40 udelay(DELAY_ABORT_SEQ); 41 last = in_8(&base->dr); 42 nbr_read++; 43 44 /* 45 * do read until the last bit is 1, but stop if the full eeprom is 46 * read. 47 */ 48 while (((last & 0x01) != 0x01) && 49 (nbr_read < CONFIG_SYS_IVM_EEPROM_MAX_LEN)) { 50 udelay(DELAY_ABORT_SEQ); 51 last = in_8(&base->dr); 52 nbr_read++; 53 } 54 if ((last & 0x01) != 0x01) 55 ret = -2; 56 if ((last != 0xff) || (nbr_read > 1)) 57 printf("[INFO] i2c abort after %d bytes (0x%02x)\n", 58 nbr_read, last); 59 udelay(DELAY_ABORT_SEQ); 60 out_8(&base->cr, (I2C_CR_MEN)); 61 udelay(DELAY_ABORT_SEQ); 62 /* clear status reg */ 63 out_8(&base->sr, 0); 64 65 for (i = 0; i < 5; i++) 66 i2c_write_start_seq(); 67 if (ret != 0) 68 printf("[ERROR] i2c abort failed after %d bytes (0x%02x)\n", 69 nbr_read, last); 70 71 return ret; 72 } 73