+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0+
-/*
- * Freescale i.MX28 I2C Driver
- *
- * Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
- * on behalf of DENX Software Engineering GmbH
- *
- * Partly based on Linux kernel i2c-mxs.c driver:
- * Copyright (C) 2011 Wolfram Sang, Pengutronix e.K.
- *
- * Which was based on a (non-working) driver which was:
- * Copyright (C) 2009-2010 Freescale Semiconductor, Inc. All Rights Reserved.
- */
-
-#include <common.h>
-#include <malloc.h>
-#include <i2c.h>
-#include <linux/errno.h>
-#include <asm/io.h>
-#include <asm/arch/clock.h>
-#include <asm/arch/imx-regs.h>
-#include <asm/arch/sys_proto.h>
-
-#define MXS_I2C_MAX_TIMEOUT 1000000
-
-static struct mxs_i2c_regs *mxs_i2c_get_base(struct i2c_adapter *adap)
-{
- if (adap->hwadapnr == 0)
- return (struct mxs_i2c_regs *)MXS_I2C0_BASE;
- else
- return (struct mxs_i2c_regs *)MXS_I2C1_BASE;
-}
-
-static unsigned int mxs_i2c_get_bus_speed(struct i2c_adapter *adap)
-{
- struct mxs_i2c_regs *i2c_regs = mxs_i2c_get_base(adap);
- uint32_t clk = mxc_get_clock(MXC_XTAL_CLK);
- uint32_t timing0;
-
- timing0 = readl(&i2c_regs->hw_i2c_timing0);
- /*
- * This is a reverse version of the algorithm presented in
- * i2c_set_bus_speed(). Please refer there for details.
- */
- return clk / ((((timing0 >> 16) - 3) * 2) + 38);
-}
-
-static uint mxs_i2c_set_bus_speed(struct i2c_adapter *adap, uint speed)
-{
- struct mxs_i2c_regs *i2c_regs = mxs_i2c_get_base(adap);
- /*
- * The timing derivation algorithm. There is no documentation for this
- * algorithm available, it was derived by using the scope and fiddling
- * with constants until the result observed on the scope was good enough
- * for 20kHz, 50kHz, 100kHz, 200kHz, 300kHz and 400kHz. It should be
- * possible to assume the algorithm works for other frequencies as well.
- *
- * Note it was necessary to cap the frequency on both ends as it's not
- * possible to configure completely arbitrary frequency for the I2C bus
- * clock.
- */
- uint32_t clk = mxc_get_clock(MXC_XTAL_CLK);
- uint32_t base = ((clk / speed) - 38) / 2;
- uint16_t high_count = base + 3;
- uint16_t low_count = base - 3;
- uint16_t rcv_count = (high_count * 3) / 4;
- uint16_t xmit_count = low_count / 4;
-
- if (speed > 540000) {
- printf("MXS I2C: Speed too high (%d Hz)\n", speed);
- return -EINVAL;
- }
-
- if (speed < 12000) {
- printf("MXS I2C: Speed too low (%d Hz)\n", speed);
- return -EINVAL;
- }
-
- writel((high_count << 16) | rcv_count, &i2c_regs->hw_i2c_timing0);
- writel((low_count << 16) | xmit_count, &i2c_regs->hw_i2c_timing1);
-
- writel((0x0030 << I2C_TIMING2_BUS_FREE_OFFSET) |
- (0x0030 << I2C_TIMING2_LEADIN_COUNT_OFFSET),
- &i2c_regs->hw_i2c_timing2);
-
- return 0;
-}
-
-static void mxs_i2c_reset(struct i2c_adapter *adap)
-{
- struct mxs_i2c_regs *i2c_regs = mxs_i2c_get_base(adap);
- int ret;
- int speed = mxs_i2c_get_bus_speed(adap);
-
- ret = mxs_reset_block(&i2c_regs->hw_i2c_ctrl0_reg);
- if (ret) {
- debug("MXS I2C: Block reset timeout\n");
- return;
- }
-
- writel(I2C_CTRL1_DATA_ENGINE_CMPLT_IRQ | I2C_CTRL1_NO_SLAVE_ACK_IRQ |
- I2C_CTRL1_EARLY_TERM_IRQ | I2C_CTRL1_MASTER_LOSS_IRQ |
- I2C_CTRL1_SLAVE_STOP_IRQ | I2C_CTRL1_SLAVE_IRQ,
- &i2c_regs->hw_i2c_ctrl1_clr);
-
- writel(I2C_QUEUECTRL_PIO_QUEUE_MODE, &i2c_regs->hw_i2c_queuectrl_set);
-
- mxs_i2c_set_bus_speed(adap, speed);
-}
-
-static void mxs_i2c_setup_read(struct i2c_adapter *adap, uint8_t chip, int len)
-{
- struct mxs_i2c_regs *i2c_regs = mxs_i2c_get_base(adap);
-
- writel(I2C_QUEUECMD_RETAIN_CLOCK | I2C_QUEUECMD_PRE_SEND_START |
- I2C_QUEUECMD_MASTER_MODE | I2C_QUEUECMD_DIRECTION |
- (1 << I2C_QUEUECMD_XFER_COUNT_OFFSET),
- &i2c_regs->hw_i2c_queuecmd);
-
- writel((chip << 1) | 1, &i2c_regs->hw_i2c_data);
-
- writel(I2C_QUEUECMD_SEND_NAK_ON_LAST | I2C_QUEUECMD_MASTER_MODE |
- (len << I2C_QUEUECMD_XFER_COUNT_OFFSET) |
- I2C_QUEUECMD_POST_SEND_STOP, &i2c_regs->hw_i2c_queuecmd);
-
- writel(I2C_QUEUECTRL_QUEUE_RUN, &i2c_regs->hw_i2c_queuectrl_set);
-}
-
-static int mxs_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
- int alen, uchar *buf, int blen, int stop)
-{
- struct mxs_i2c_regs *i2c_regs = mxs_i2c_get_base(adap);
- uint32_t data, tmp;
- int i, remain, off;
- int timeout = MXS_I2C_MAX_TIMEOUT;
-
- if ((alen > 4) || (alen == 0)) {
- debug("MXS I2C: Invalid address length\n");
- return -EINVAL;
- }
-
- if (stop)
- stop = I2C_QUEUECMD_POST_SEND_STOP;
-
- writel(I2C_QUEUECMD_PRE_SEND_START |
- I2C_QUEUECMD_MASTER_MODE | I2C_QUEUECMD_DIRECTION |
- ((blen + alen + 1) << I2C_QUEUECMD_XFER_COUNT_OFFSET) | stop,
- &i2c_regs->hw_i2c_queuecmd);
-
- data = (chip << 1) << 24;
-
- for (i = 0; i < alen; i++) {
- data >>= 8;
- data |= ((char *)&addr)[alen - i - 1] << 24;
- if ((i & 3) == 2)
- writel(data, &i2c_regs->hw_i2c_data);
- }
-
- off = i;
- for (; i < off + blen; i++) {
- data >>= 8;
- data |= buf[i - off] << 24;
- if ((i & 3) == 2)
- writel(data, &i2c_regs->hw_i2c_data);
- }
-
- remain = 24 - ((i & 3) * 8);
- if (remain)
- writel(data >> remain, &i2c_regs->hw_i2c_data);
-
- writel(I2C_QUEUECTRL_QUEUE_RUN, &i2c_regs->hw_i2c_queuectrl_set);
-
- while (--timeout) {
- tmp = readl(&i2c_regs->hw_i2c_queuestat);
- if (tmp & I2C_QUEUESTAT_WR_QUEUE_EMPTY)
- break;
- }
-
- if (!timeout) {
- debug("MXS I2C: Failed transmitting data!\n");
- return -EINVAL;
- }
-
- return 0;
-}
-
-static int mxs_i2c_wait_for_ack(struct i2c_adapter *adap)
-{
- struct mxs_i2c_regs *i2c_regs = mxs_i2c_get_base(adap);
- uint32_t tmp;
- int timeout = MXS_I2C_MAX_TIMEOUT;
-
- for (;;) {
- tmp = readl(&i2c_regs->hw_i2c_ctrl1);
- if (tmp & I2C_CTRL1_NO_SLAVE_ACK_IRQ) {
- debug("MXS I2C: No slave ACK\n");
- goto err;
- }
-
- if (tmp & (
- I2C_CTRL1_EARLY_TERM_IRQ | I2C_CTRL1_MASTER_LOSS_IRQ |
- I2C_CTRL1_SLAVE_STOP_IRQ | I2C_CTRL1_SLAVE_IRQ)) {
- debug("MXS I2C: Error (CTRL1 = %08x)\n", tmp);
- goto err;
- }
-
- if (tmp & I2C_CTRL1_DATA_ENGINE_CMPLT_IRQ)
- break;
-
- if (!timeout--) {
- debug("MXS I2C: Operation timed out\n");
- goto err;
- }
-
- udelay(1);
- }
-
- return 0;
-
-err:
- mxs_i2c_reset(adap);
- return 1;
-}
-
-static int mxs_i2c_if_read(struct i2c_adapter *adap, uint8_t chip,
- uint addr, int alen, uint8_t *buffer,
- int len)
-{
- struct mxs_i2c_regs *i2c_regs = mxs_i2c_get_base(adap);
- uint32_t tmp = 0;
- int timeout = MXS_I2C_MAX_TIMEOUT;
- int ret;
- int i;
-
- ret = mxs_i2c_write(adap, chip, addr, alen, NULL, 0, 0);
- if (ret) {
- debug("MXS I2C: Failed writing address\n");
- return ret;
- }
-
- ret = mxs_i2c_wait_for_ack(adap);
- if (ret) {
- debug("MXS I2C: Failed writing address\n");
- return ret;
- }
-
- mxs_i2c_setup_read(adap, chip, len);
- ret = mxs_i2c_wait_for_ack(adap);
- if (ret) {
- debug("MXS I2C: Failed reading address\n");
- return ret;
- }
-
- for (i = 0; i < len; i++) {
- if (!(i & 3)) {
- while (--timeout) {
- tmp = readl(&i2c_regs->hw_i2c_queuestat);
- if (!(tmp & I2C_QUEUESTAT_RD_QUEUE_EMPTY))
- break;
- }
-
- if (!timeout) {
- debug("MXS I2C: Failed receiving data!\n");
- return -ETIMEDOUT;
- }
-
- tmp = readl(&i2c_regs->hw_i2c_queuedata);
- }
- buffer[i] = tmp & 0xff;
- tmp >>= 8;
- }
-
- return 0;
-}
-
-static int mxs_i2c_if_write(struct i2c_adapter *adap, uint8_t chip,
- uint addr, int alen, uint8_t *buffer,
- int len)
-{
- int ret;
- ret = mxs_i2c_write(adap, chip, addr, alen, buffer, len, 1);
- if (ret) {
- debug("MXS I2C: Failed writing address\n");
- return ret;
- }
-
- ret = mxs_i2c_wait_for_ack(adap);
- if (ret)
- debug("MXS I2C: Failed writing address\n");
-
- return ret;
-}
-
-static int mxs_i2c_probe(struct i2c_adapter *adap, uint8_t chip)
-{
- int ret;
- ret = mxs_i2c_write(adap, chip, 0, 1, NULL, 0, 1);
- if (!ret)
- ret = mxs_i2c_wait_for_ack(adap);
- mxs_i2c_reset(adap);
- return ret;
-}
-
-static void mxs_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
-{
- mxs_i2c_reset(adap);
- mxs_i2c_set_bus_speed(adap, speed);
-
- return;
-}
-
-U_BOOT_I2C_ADAP_COMPLETE(mxs0, mxs_i2c_init, mxs_i2c_probe,
- mxs_i2c_if_read, mxs_i2c_if_write,
- mxs_i2c_set_bus_speed,
- CONFIG_SYS_I2C_SPEED, 0, 0)
-U_BOOT_I2C_ADAP_COMPLETE(mxs1, mxs_i2c_init, mxs_i2c_probe,
- mxs_i2c_if_read, mxs_i2c_if_write,
- mxs_i2c_set_bus_speed,
- CONFIG_SYS_I2C_SPEED, 0, 1)
projects / oweals / u-boot.git / commitdiff