[U-Boot] [PATCH 05/15] iMX28: Add I2C bus driver

Marek Vasut
2011-09-12T04:06:39Z

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Cc: Heiko Schocher <hs@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Detlev Zundel <dzu@denx.de>
---
drivers/i2c/Makefile | 1 +
drivers/i2c/mxs_i2c.c | 240 +++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 241 insertions(+), 0 deletions(-)
create mode 100644 drivers/i2c/mxs_i2c.c

diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
index a48047a..2fb521e 100644
--- a/drivers/i2c/Makefile
+++ b/drivers/i2c/Makefile
@@ -31,6 +31,7 @@ COBJS-$(CONFIG_FSL_I2C) += fsl_i2c.o
COBJS-$(CONFIG_I2C_MVTWSI) += mvtwsi.o
COBJS-$(CONFIG_I2C_MV) += mv_i2c.o
COBJS-$(CONFIG_I2C_MXC) += mxc_i2c.o
+COBJS-$(CONFIG_I2C_MXS) += mxs_i2c.o
COBJS-$(CONFIG_DRIVER_OMAP1510_I2C) += omap1510_i2c.o
COBJS-$(CONFIG_DRIVER_OMAP24XX_I2C) += omap24xx_i2c.o
COBJS-$(CONFIG_DRIVER_OMAP34XX_I2C) += omap24xx_i2c.o
diff --git a/drivers/i2c/mxs_i2c.c b/drivers/i2c/mxs_i2c.c
new file mode 100644
index 0000000..9f380a0
--- /dev/null
+++ b/drivers/i2c/mxs_i2c.c
@@ -0,0 +1,240 @@
+/*
+ * Freescale i.MX28 I2C Driver
+ *
+ * Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
+ * on behalf of DENX Software Engineering GmbH
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <asm/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
+
+void mxs_i2c_reset(void)
+{
+ struct mx28_i2c_regs *i2c_regs = (struct mx28_i2c_regs *)MXS_I2C0_BASE;
+ int ret;
+
+ ret = mx28_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);
+}
+
+void mxs_i2c_setup_read(uint8_t chip, int len)
+{
+ struct mx28_i2c_regs *i2c_regs = (struct mx28_i2c_regs *)MXS_I2C0_BASE;
+
+ 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);
+}
+
+void mxs_i2c_write(uchar chip, uint addr, int alen,
+ uchar *buf, int blen, int stop)
+{
+ struct mx28_i2c_regs *i2c_regs = (struct mx28_i2c_regs *)MXS_I2C0_BASE;
+ uint32_t data;
+ int i, remain, off;
+
+ if ((alen > 4) || (alen == 0)) {
+ debug("MXS I2C: Invalid address length\n");
+ return;
+ }
+
+ 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)[i] << 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);
+}
+
+int mxs_i2c_wait_for_ack(void)
+{
+ struct mx28_i2c_regs *i2c_regs = (struct mx28_i2c_regs *)MXS_I2C0_BASE;
+ 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();
+ return 1;
+}
+
+int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
+{
+ struct mx28_i2c_regs *i2c_regs = (struct mx28_i2c_regs *)MXS_I2C0_BASE;
+ uint32_t tmp = 0;
+ int ret;
+ int i;
+
+ mxs_i2c_write(chip, addr, alen, NULL, 0, 0);
+ ret = mxs_i2c_wait_for_ack();
+ if (ret) {
+ debug("MXS I2C: Failed writing address\n");
+ return ret;
+ }
+
+ mxs_i2c_setup_read(chip, len);
+ ret = mxs_i2c_wait_for_ack();
+ if (ret) {
+ debug("MXS I2C: Failed reading address\n");
+ return ret;
+ }
+
+ for (i = 0; i < len; i++) {
+ if (!(i & 3)) {
+ while (readl(&i2c_regs->hw_i2c_queuestat) &
+ I2C_QUEUESTAT_RD_QUEUE_EMPTY)
+ ;
+ tmp = readl(&i2c_regs->hw_i2c_queuedata);
+ }
+ buffer[i] = tmp & 0xff;
+ tmp >>= 8;
+ }
+
+ return 0;
+}
+
+int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
+{
+ int ret;
+ mxs_i2c_write(chip, addr, alen, buffer, len, 1);
+ ret = mxs_i2c_wait_for_ack();
+ if (ret)
+ debug("MXS I2C: Failed writing address\n");
+
+ return ret;
+}
+
+int i2c_probe(uchar chip)
+{
+ int ret;
+ mxs_i2c_write(chip, 0, 1, NULL, 0, 1);
+ ret = mxs_i2c_wait_for_ack();
+ mxs_i2c_reset();
+ return ret;
+}
+
+void i2c_init(int speed, int slaveadd)
+{
+ struct mx28_i2c_regs *i2c_regs = (struct mx28_i2c_regs *)MXS_I2C0_BASE;
+
+ mxs_i2c_reset();
+
+ switch (speed) {
+ case 100000:
+ writel((0x0078 << I2C_TIMING0_HIGH_COUNT_OFFSET) |
+ (0x0030 << I2C_TIMING0_RCV_COUNT_OFFSET),
+ &i2c_regs->hw_i2c_timing0);
+ writel((0x0080 << I2C_TIMING1_LOW_COUNT_OFFSET) |
+ (0x0030 << I2C_TIMING1_XMIT_COUNT_OFFSET),
+ &i2c_regs->hw_i2c_timing1);
+ break;
+ case 400000:
+ writel((0x000f << I2C_TIMING0_HIGH_COUNT_OFFSET) |
+ (0x0007 << I2C_TIMING0_RCV_COUNT_OFFSET),
+ &i2c_regs->hw_i2c_timing0);
+ writel((0x001f << I2C_TIMING1_LOW_COUNT_OFFSET) |
+ (0x000f << I2C_TIMING1_XMIT_COUNT_OFFSET),
+ &i2c_regs->hw_i2c_timing1);
+ break;
+ default:
+ printf("MXS I2C: Invalid speed selected (%d Hz)\n", speed);
+ return;
+ }
+
+ writel((0x0015 << I2C_TIMING2_BUS_FREE_OFFSET) |
+ (0x000d << I2C_TIMING2_LEADIN_COUNT_OFFSET),
+ &i2c_regs->hw_i2c_timing2);
+
+ return;
+}
--
1.7.5.4