diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/i2c/Makefile | 1 | ||||
| -rw-r--r-- | drivers/i2c/bfin-twi_i2c.c | 74 | ||||
| -rw-r--r-- | drivers/i2c/pca9564_i2c.c | 189 |
3 files changed, 250 insertions, 14 deletions
diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile index 4a12976e3..b860e89f8 100644 --- a/drivers/i2c/Makefile +++ b/drivers/i2c/Makefile @@ -33,6 +33,7 @@ COBJS-$(CONFIG_I2C_MXC) += mxc_i2c.o COBJS-$(CONFIG_DRIVER_OMAP1510_I2C) += omap1510_i2c.o COBJS-$(CONFIG_DRIVER_OMAP24XX_I2C) += omap24xx_i2c.o COBJS-$(CONFIG_DRIVER_OMAP34XX_I2C) += omap24xx_i2c.o +COBJS-$(CONFIG_PCA9564_I2C) += pca9564_i2c.o COBJS-$(CONFIG_DRIVER_S3C24X0_I2C) += s3c24x0_i2c.o COBJS-$(CONFIG_S3C44B0_I2C) += s3c44b0_i2c.o COBJS-$(CONFIG_SOFT_I2C) += soft_i2c.o diff --git a/drivers/i2c/bfin-twi_i2c.c b/drivers/i2c/bfin-twi_i2c.c index e79063407..73a78d223 100644 --- a/drivers/i2c/bfin-twi_i2c.c +++ b/drivers/i2c/bfin-twi_i2c.c @@ -26,6 +26,7 @@ #ifdef TWI0_CLKDIV #define bfin_write_TWI_CLKDIV(val) bfin_write_TWI0_CLKDIV(val) +#define bfin_read_TWI_CLKDIV(val) bfin_read_TWI0_CLKDIV(val) #define bfin_write_TWI_CONTROL(val) bfin_write_TWI0_CONTROL(val) #define bfin_read_TWI_CONTROL(val) bfin_read_TWI0_CONTROL(val) #define bfin_write_TWI_MASTER_ADDR(val) bfin_write_TWI0_MASTER_ADDR(val) @@ -44,8 +45,21 @@ #ifdef CONFIG_TWICLK_KHZ # error do not define CONFIG_TWICLK_KHZ ... use CONFIG_SYS_I2C_SPEED #endif -#if CONFIG_SYS_I2C_SPEED > 400000 -# error The Blackfin I2C hardware can only operate at 400KHz max + +/* + * The way speed is changed into duty often results in integer truncation + * with 50% duty, so we'll force rounding up to the next duty by adding 1 + * to the max. In practice this will get us a speed of something like + * 385 KHz. The other limit is easy to handle as it is only 8 bits. + */ +#define I2C_SPEED_MAX 400000 +#define I2C_SPEED_TO_DUTY(speed) (5000000 / (speed)) +#define I2C_DUTY_MAX (I2C_SPEED_TO_DUTY(I2C_SPEED_MAX) + 1) +#define I2C_DUTY_MIN 0xff /* 8 bit limited */ +#define SYS_I2C_DUTY I2C_SPEED_TO_DUTY(CONFIG_SYS_I2C_SPEED) +/* Note: duty is inverse of speed, so the comparisons below are correct */ +#if SYS_I2C_DUTY < I2C_DUTY_MAX || SYS_I2C_DUTY > I2C_DUTY_MIN +# error "The Blackfin I2C hardware can only operate 20KHz - 400KHz" #endif /* All transfers are described by this data structure */ @@ -60,6 +74,9 @@ struct i2c_msg { u8 *abuf; /* addr buffer */ }; +/* Allow msec timeout per ~byte transfer */ +#define I2C_TIMEOUT 10 + /** * wait_for_completion - manage the actual i2c transfer * @msg: the i2c msg @@ -67,8 +84,9 @@ struct i2c_msg { static int wait_for_completion(struct i2c_msg *msg) { uint16_t int_stat; + ulong timebase = get_timer(0); - while (!ctrlc()) { + do { int_stat = bfin_read_TWI_INT_STAT(); if (int_stat & XMTSERV) { @@ -103,7 +121,7 @@ static int wait_for_completion(struct i2c_msg *msg) debugi("processing MERR"); bfin_write_TWI_INT_STAT(MERR); SSYNC(); - break; + return msg->len; } if (int_stat & MCOMP) { debugi("processing MCOMP"); @@ -116,7 +134,12 @@ static int wait_for_completion(struct i2c_msg *msg) } else break; } - } + + /* If we were able to do something, reset timeout */ + if (int_stat) + timebase = get_timer(0); + + } while (get_timer(timebase) < I2C_TIMEOUT); return msg->len; } @@ -204,7 +227,36 @@ static int i2c_transfer(uchar chip, uint addr, int alen, uchar *buffer, int len, return ret; } -/* +/** + * i2c_set_bus_speed - set i2c bus speed + * @speed: bus speed (in HZ) + */ +int i2c_set_bus_speed(unsigned int speed) +{ + u16 clkdiv = I2C_SPEED_TO_DUTY(speed); + + /* Set TWI interface clock */ + if (clkdiv < I2C_DUTY_MAX || clkdiv > I2C_DUTY_MIN) + return -1; + bfin_write_TWI_CLKDIV((clkdiv << 8) | (clkdiv & 0xff)); + + /* Don't turn it on */ + bfin_write_TWI_MASTER_CTL(speed > 100000 ? FAST : 0); + + return 0; +} + +/** + * i2c_get_bus_speed - get i2c bus speed + * @speed: bus speed (in HZ) + */ +unsigned int i2c_get_bus_speed(void) +{ + /* 10 MHz / (2 * CLKDIV) -> 5 MHz / CLKDIV */ + return 5000000 / (bfin_read_TWI_CLKDIV() & 0xff); +} + +/** * i2c_init - initialize the i2c bus * @speed: bus speed (in HZ) * @slaveaddr: address of device in slave mode (0 - not slave) @@ -220,15 +272,9 @@ void i2c_init(int speed, int slaveaddr) bfin_write_TWI_CONTROL(prescale); /* Set TWI interface clock as specified */ - bfin_write_TWI_CLKDIV( - ((5 * 1024 / (speed / 1000)) << 8) | - ((5 * 1024 / (speed / 1000)) & 0xFF) - ); - - /* Don't turn it on */ - bfin_write_TWI_MASTER_CTL(speed > 100000 ? FAST : 0); + i2c_set_bus_speed(speed); - /* But enable it */ + /* Enable it */ bfin_write_TWI_CONTROL(TWI_ENA | prescale); SSYNC(); diff --git a/drivers/i2c/pca9564_i2c.c b/drivers/i2c/pca9564_i2c.c new file mode 100644 index 000000000..199a9ee39 --- /dev/null +++ b/drivers/i2c/pca9564_i2c.c @@ -0,0 +1,189 @@ +/* + * File: drivers/i2c/pca9564.c + * Based on: drivers/i2c/s3c44b0_i2c.c + * Author: + * + * Created: 2009-06-23 + * Description: PCA9564 i2c bridge driver + * + * Modified: + * Copyright 2009 CJSC "NII STT", http://www.niistt.ru/ + * + * Bugs: + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see the file COPYING, or write + * to the Free Software Foundation, Inc., + * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <common.h> +#include <i2c.h> +#include <pca9564.h> +#include <asm/io.h> + +#define PCA_STA (CONFIG_PCA9564_BASE + 0) +#define PCA_TO (CONFIG_PCA9564_BASE + 0) +#define PCA_DAT (CONFIG_PCA9564_BASE + (1 << 2)) +#define PCA_ADR (CONFIG_PCA9564_BASE + (2 << 2)) +#define PCA_CON (CONFIG_PCA9564_BASE + (3 << 2)) + +static unsigned char pca_read_reg(unsigned int reg) +{ + return readb((void *)reg); +} + +static void pca_write_reg(unsigned int reg, unsigned char value) +{ + writeb(value, (void *)reg); +} + +static int pca_wait_busy(void) +{ + unsigned int timeout = 10000; + + while (!(pca_read_reg(PCA_CON) & PCA_CON_SI) && --timeout) + udelay(1); + + if (timeout == 0) + debug("I2C timeout!\n"); + + debug("CON = 0x%02x, STA = 0x%02x\n", pca_read_reg(PCA_CON), + pca_read_reg(PCA_STA)); + + return timeout ? 0 : 1; +} + +/*=====================================================================*/ +/* Public Functions */ +/*=====================================================================*/ + +/*----------------------------------------------------------------------- + * Initialization + */ +void i2c_init(int speed, int slaveaddr) +{ + pca_write_reg(PCA_CON, PCA_CON_ENSIO | speed); +} + +/* + * Probe the given I2C chip address. Returns 0 if a chip responded, + * not 0 on failure. + */ + +int i2c_probe(uchar chip) +{ + unsigned char res; + + pca_write_reg(PCA_CON, PCA_CON_STA | PCA_CON_ENSIO); + pca_wait_busy(); + + pca_write_reg(PCA_CON, PCA_CON_STA | PCA_CON_ENSIO); + + pca_write_reg(PCA_DAT, (chip << 1) | 1); + res = pca_wait_busy(); + + if ((res == 0) && (pca_read_reg(PCA_STA) == 0x48)) + res = 1; + + pca_write_reg(PCA_CON, PCA_CON_STO | PCA_CON_ENSIO); + + return res; +} + +/* + * Read/Write interface: + * chip: I2C chip address, range 0..127 + * addr: Memory (register) address within the chip + * alen: Number of bytes to use for addr (typically 1, 2 for larger + * memories, 0 for register type devices with only one + * register) + * buffer: Where to read/write the data + * len: How many bytes to read/write + * + * Returns: 0 on success, not 0 on failure + */ +int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len) +{ + int i; + + pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA); + pca_wait_busy(); + + pca_write_reg(PCA_CON, PCA_CON_ENSIO); + + pca_write_reg(PCA_DAT, (chip << 1)); + pca_wait_busy(); + pca_write_reg(PCA_CON, PCA_CON_ENSIO); + + if (alen > 0) { + pca_write_reg(PCA_DAT, addr); + pca_wait_busy(); + pca_write_reg(PCA_CON, PCA_CON_ENSIO); + } + + pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STO); + + udelay(500); + + pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA); + pca_wait_busy(); + pca_write_reg(PCA_CON, PCA_CON_ENSIO); + + pca_write_reg(PCA_DAT, (chip << 1) | 1); + pca_wait_busy(); + + for (i = 0; i < len; ++i) { + if (i == len - 1) + pca_write_reg(PCA_CON, PCA_CON_ENSIO); + else + pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_AA); + + pca_wait_busy(); + buffer[i] = pca_read_reg(PCA_DAT); + + } + + pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STO); + + return 0; +} + +int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len) +{ + int i; + + pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA); + pca_wait_busy(); + pca_write_reg(PCA_CON, PCA_CON_ENSIO); + + pca_write_reg(PCA_DAT, chip << 1); + pca_wait_busy(); + pca_write_reg(PCA_CON, PCA_CON_ENSIO); + + if (alen > 0) { + pca_write_reg(PCA_DAT, addr); + pca_wait_busy(); + pca_write_reg(PCA_CON, PCA_CON_ENSIO); + } + + for (i = 0; i < len; ++i) { + pca_write_reg(PCA_DAT, buffer[i]); + pca_wait_busy(); + pca_write_reg(PCA_CON, PCA_CON_ENSIO); + } + + pca_write_reg(PCA_CON, PCA_CON_STO | PCA_CON_ENSIO); + + return 0; +} |