diff options
| -rw-r--r-- | README | 7 | ||||
| -rw-r--r-- | cpu/mpc5xxx/i2c.c | 49 | ||||
| -rw-r--r-- | drivers/i2c/fsl_i2c.c | 24 | ||||
| -rw-r--r-- | include/configs/galaxy5200.h | 1 |
4 files changed, 77 insertions, 4 deletions
@@ -1366,6 +1366,13 @@ The following options need to be configured: therefore be cleared to 0 (See, eg, MPC823e User's Manual p.16-473). So, set CONFIG_SYS_I2C_SLAVE to 0. + CONFIG_SYS_I2C_INIT_MPC5XXX + + When a board is reset during an i2c bus transfer + chips might think that the current transfer is still + in progress. Reset the slave devices by sending start + commands until the slave device responds. + That's all that's required for CONFIG_HARD_I2C. If you use the software i2c interface (CONFIG_SOFT_I2C) diff --git a/cpu/mpc5xxx/i2c.c b/cpu/mpc5xxx/i2c.c index 2341932..4f7f716 100644 --- a/cpu/mpc5xxx/i2c.c +++ b/cpu/mpc5xxx/i2c.c @@ -207,6 +207,52 @@ static int receive_bytes(uchar chip, char *buf, int len) return 0; } +#if defined(CONFIG_SYS_I2C_INIT_MPC5XXX) + +#define FDR510(x) (u8) (((x & 0x20) >> 3) | (x & 0x3)) +#define FDR432(x) (u8) ((x & 0x1C) >> 2) +/* + * Reset any i2c devices that may have been interrupted during a system reset. + * Normally this would be accomplished by clocking the line until SCL and SDA + * are released and then sending a start condtiion (From an Atmel datasheet). + * There is no direct access to the i2c pins so instead create start commands + * through the i2c interface. Send a start command then delay for the SDA Hold + * time, repeat this by disabling/enabling the bus a total of 9 times. + */ +static void send_reset(void) +{ + struct mpc5xxx_i2c *regs = (struct mpc5xxx_i2c *)I2C_BASE; + int i; + u32 delay; + u8 fdr; + int SDA_Tap[] = { 3, 3, 4, 4, 1, 1, 2, 2}; + struct mpc5xxx_i2c_tap scltap[] = { + {4, 1}, + {4, 2}, + {6, 4}, + {6, 8}, + {14, 16}, + {30, 32}, + {62, 64}, + {126, 128} + }; + + fdr = (u8)mpc_reg_in(®s->mfdr); + + delay = scltap[FDR432(fdr)].scl2tap + ((SDA_Tap[FDR510(fdr)] - 1) * \ + scltap[FDR432(fdr)].tap2tap) + 3; + + for (i = 0; i < 9; i++) { + mpc_reg_out(®s->mcr, I2C_EN|I2C_STA|I2C_TX, I2C_INIT_MASK); + udelay(delay); + mpc_reg_out(®s->mcr, 0, I2C_INIT_MASK); + udelay(delay); + } + + mpc_reg_out(®s->mcr, I2C_EN, I2C_INIT_MASK); +} +#endif /* CONFIG_SYS_I2c_INIT_MPC5XXX */ + /**************** I2C API ****************/ void i2c_init(int speed, int saddr) @@ -225,6 +271,9 @@ void i2c_init(int speed, int saddr) mpc_reg_out(®s->mcr, I2C_EN, I2C_INIT_MASK); mpc_reg_out(®s->msr, 0, I2C_IF); +#if defined(CONFIG_SYS_I2C_INIT_MPC5XXX) + send_reset(); +#endif return; } diff --git a/drivers/i2c/fsl_i2c.c b/drivers/i2c/fsl_i2c.c index ce0f301..47bbf79 100644 --- a/drivers/i2c/fsl_i2c.c +++ b/drivers/i2c/fsl_i2c.c @@ -1,5 +1,5 @@ /* - * Copyright 2006 Freescale Semiconductor, Inc. + * Copyright 2006,2009 Freescale Semiconductor, Inc. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License @@ -26,7 +26,21 @@ #include <asm/io.h> #include <asm/fsl_i2c.h> /* HW definitions */ -#define I2C_TIMEOUT (CONFIG_SYS_HZ / 4) +/* The maximum number of microseconds we will wait until another master has + * released the bus. If not defined in the board header file, then use a + * generic value. + */ +#ifndef CONFIG_I2C_MBB_TIMEOUT +#define CONFIG_I2C_MBB_TIMEOUT 100000 +#endif + +/* The maximum number of microseconds we will wait for a read or write + * operation to complete. If not defined in the board header file, then use a + * generic value. + */ +#ifndef CONFIG_I2C_TIMEOUT +#define CONFIG_I2C_TIMEOUT 10000 +#endif #define I2C_READ_BIT 1 #define I2C_WRITE_BIT 0 @@ -213,9 +227,10 @@ static __inline__ int i2c_wait4bus(void) { unsigned long long timeval = get_ticks(); + const unsigned long long timeout = usec2ticks(CONFIG_I2C_MBB_TIMEOUT); while (readb(&i2c_dev[i2c_bus_num]->sr) & I2C_SR_MBB) { - if ((get_ticks() - timeval) > usec2ticks(I2C_TIMEOUT)) + if ((get_ticks() - timeval) > timeout) return -1; } @@ -227,6 +242,7 @@ i2c_wait(int write) { u32 csr; unsigned long long timeval = get_ticks(); + const unsigned long long timeout = usec2ticks(CONFIG_I2C_TIMEOUT); do { csr = readb(&i2c_dev[i2c_bus_num]->sr); @@ -251,7 +267,7 @@ i2c_wait(int write) } return 0; - } while ((get_ticks() - timeval) < usec2ticks(I2C_TIMEOUT)); + } while ((get_ticks() - timeval) < timeout); debug("i2c_wait: timed out\n"); return -1; diff --git a/include/configs/galaxy5200.h b/include/configs/galaxy5200.h index a5b5a03..f4b520d 100644 --- a/include/configs/galaxy5200.h +++ b/include/configs/galaxy5200.h @@ -110,6 +110,7 @@ #define CONFIG_SYS_I2C_MODULE 2 /* Select I2C module #1 or #2 */ #define CONFIG_SYS_I2C_SPEED 100000 /* 100 kHz */ #define CONFIG_SYS_I2C_SLAVE 0x7F +#define CONFIG_SYS_I2C_INIT_MPC5XXX /* Reset devices on i2c bus */ /* * EEPROM CAT24WC32 configuration |