forked from rrcarlosr/Jetpack
177 lines
3.9 KiB
C
177 lines
3.9 KiB
C
/*
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* File: drivers/i2c/pca9564.c
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* Based on: drivers/i2c/s3c44b0_i2c.c
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* Author:
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*
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* Created: 2009-06-23
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* Description: PCA9564 i2c bridge driver
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*
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* Modified:
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* Copyright 2009 CJSC "NII STT", http://www.niistt.ru/
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*
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* Bugs:
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <common.h>
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#include <i2c.h>
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#include <pca9564.h>
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#include <asm/io.h>
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#define PCA_STA (CONFIG_PCA9564_BASE + 0)
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#define PCA_TO (CONFIG_PCA9564_BASE + 0)
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#define PCA_DAT (CONFIG_PCA9564_BASE + (1 << 2))
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#define PCA_ADR (CONFIG_PCA9564_BASE + (2 << 2))
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#define PCA_CON (CONFIG_PCA9564_BASE + (3 << 2))
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static unsigned char pca_read_reg(unsigned int reg)
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{
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return readb((void *)reg);
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}
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static void pca_write_reg(unsigned int reg, unsigned char value)
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{
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writeb(value, (void *)reg);
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}
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static int pca_wait_busy(void)
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{
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unsigned int timeout = 10000;
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while (!(pca_read_reg(PCA_CON) & PCA_CON_SI) && --timeout)
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udelay(1);
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if (timeout == 0)
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debug("I2C timeout!\n");
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debug("CON = 0x%02x, STA = 0x%02x\n", pca_read_reg(PCA_CON),
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pca_read_reg(PCA_STA));
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return timeout ? 0 : 1;
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}
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/*=====================================================================*/
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/* Public Functions */
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/*=====================================================================*/
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/*-----------------------------------------------------------------------
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* Initialization
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*/
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void i2c_init(int speed, int slaveaddr)
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{
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pca_write_reg(PCA_CON, PCA_CON_ENSIO | speed);
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}
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/*
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* Probe the given I2C chip address. Returns 0 if a chip responded,
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* not 0 on failure.
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*/
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int i2c_probe(uchar chip)
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{
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unsigned char res;
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pca_write_reg(PCA_CON, PCA_CON_STA | PCA_CON_ENSIO);
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pca_wait_busy();
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pca_write_reg(PCA_CON, PCA_CON_STA | PCA_CON_ENSIO);
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pca_write_reg(PCA_DAT, (chip << 1) | 1);
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res = pca_wait_busy();
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if ((res == 0) && (pca_read_reg(PCA_STA) == 0x48))
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res = 1;
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pca_write_reg(PCA_CON, PCA_CON_STO | PCA_CON_ENSIO);
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return res;
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}
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/*
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* Read/Write interface:
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* chip: I2C chip address, range 0..127
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* addr: Memory (register) address within the chip
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* alen: Number of bytes to use for addr (typically 1, 2 for larger
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* memories, 0 for register type devices with only one
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* register)
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* buffer: Where to read/write the data
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* len: How many bytes to read/write
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*
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* Returns: 0 on success, not 0 on failure
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*/
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int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
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{
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int i;
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pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA);
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pca_wait_busy();
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pca_write_reg(PCA_CON, PCA_CON_ENSIO);
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pca_write_reg(PCA_DAT, (chip << 1));
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pca_wait_busy();
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pca_write_reg(PCA_CON, PCA_CON_ENSIO);
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if (alen > 0) {
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pca_write_reg(PCA_DAT, addr);
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pca_wait_busy();
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pca_write_reg(PCA_CON, PCA_CON_ENSIO);
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}
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pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STO);
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udelay(500);
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pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA);
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pca_wait_busy();
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pca_write_reg(PCA_CON, PCA_CON_ENSIO);
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pca_write_reg(PCA_DAT, (chip << 1) | 1);
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pca_wait_busy();
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for (i = 0; i < len; ++i) {
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if (i == len - 1)
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pca_write_reg(PCA_CON, PCA_CON_ENSIO);
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else
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pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_AA);
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pca_wait_busy();
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buffer[i] = pca_read_reg(PCA_DAT);
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}
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pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STO);
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return 0;
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}
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int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
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{
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int i;
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pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA);
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pca_wait_busy();
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pca_write_reg(PCA_CON, PCA_CON_ENSIO);
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pca_write_reg(PCA_DAT, chip << 1);
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pca_wait_busy();
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pca_write_reg(PCA_CON, PCA_CON_ENSIO);
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if (alen > 0) {
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pca_write_reg(PCA_DAT, addr);
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pca_wait_busy();
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pca_write_reg(PCA_CON, PCA_CON_ENSIO);
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}
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for (i = 0; i < len; ++i) {
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pca_write_reg(PCA_DAT, buffer[i]);
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pca_wait_busy();
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pca_write_reg(PCA_CON, PCA_CON_ENSIO);
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}
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pca_write_reg(PCA_CON, PCA_CON_STO | PCA_CON_ENSIO);
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return 0;
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}
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