diff options
Diffstat (limited to 'drivers/i2c/pca9564_i2c.c')
| -rw-r--r-- | drivers/i2c/pca9564_i2c.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/drivers/i2c/pca9564_i2c.c b/drivers/i2c/pca9564_i2c.c new file mode 100644 index 0000000..199a9ee --- /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; +} |