[U-Boot] [PATCH v3 2/7] cros: add I2C support for cros_ec
Hung-ying Tyan
tyanh at chromium.org
Thu Mar 28 08:45:55 CET 2013
This patch adds I2C support for carrying out the cros_ec protocol.
Signed-off-by: Randall Spangler <rspangler at chromium.org>
Signed-off-by: Simon Glass <sjg at chromium.org>
Signed-off-by: Hung-ying Tyan <tyanh at chromium.org>
---
Changes in v3: None
Changes in v2:
- Fixed warnings of exceeding 80 chars in a line.
- Added Commit message.
- Dropped the period from commit subject.
drivers/misc/Makefile | 1 +
drivers/misc/cros_ec_i2c.c | 199 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 200 insertions(+)
create mode 100644 drivers/misc/cros_ec_i2c.c
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 33fe822..9363ef9 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -31,6 +31,7 @@ COBJS-$(CONFIG_CBMEM_CONSOLE) += cbmem_console.o
COBJS-$(CONFIG_GPIO_LED) += gpio_led.o
COBJS-$(CONFIG_FSL_MC9SDZ60) += mc9sdz60.o
COBJS-$(CONFIG_CROS_EC) += cros_ec.o
+COBJS-$(CONFIG_CROS_EC_I2C) += cros_ec_i2c.o
COBJS-$(CONFIG_NS87308) += ns87308.o
COBJS-$(CONFIG_PDSP188x) += pdsp188x.o
COBJS-$(CONFIG_STATUS_LED) += status_led.o
diff --git a/drivers/misc/cros_ec_i2c.c b/drivers/misc/cros_ec_i2c.c
new file mode 100644
index 0000000..b0060ac
--- /dev/null
+++ b/drivers/misc/cros_ec_i2c.c
@@ -0,0 +1,199 @@
+/*
+ * Chromium OS cros_ec driver - I2C interface
+ *
+ * Copyright (c) 2012 The Chromium OS Authors.
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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
+ */
+
+/*
+ * The Matrix Keyboard Protocol driver handles talking to the keyboard
+ * controller chip. Mostly this is for keyboard functions, but some other
+ * things have slipped in, so we provide generic services to talk to the
+ * KBC.
+ */
+
+#include <common.h>
+#include <i2c.h>
+#include <cros_ec.h>
+
+#ifdef DEBUG_TRACE
+#define debug_trace(fmt, b...) debug(fmt, #b)
+#else
+#define debug_trace(fmt, b...)
+#endif
+
+int cros_ec_i2c_command(struct cros_ec_dev *dev, uint8_t cmd, int cmd_version,
+ const uint8_t *dout, int dout_len,
+ uint8_t **dinp, int din_len)
+{
+ int old_bus = 0;
+ /* version8, cmd8, arglen8, out8[dout_len], csum8 */
+ int out_bytes = dout_len + 4;
+ /* response8, arglen8, in8[din_len], checksum8 */
+ int in_bytes = din_len + 3;
+ uint8_t *ptr;
+ /* Receive input data, so that args will be dword aligned */
+ uint8_t *in_ptr;
+ int ret;
+
+ old_bus = i2c_get_bus_num();
+
+ /*
+ * Sanity-check I/O sizes given transaction overhead in internal
+ * buffers.
+ */
+ if (out_bytes > sizeof(dev->dout)) {
+ debug("%s: Cannot send %d bytes\n", __func__, dout_len);
+ return -1;
+ }
+ if (in_bytes > sizeof(dev->din)) {
+ debug("%s: Cannot receive %d bytes\n", __func__, din_len);
+ return -1;
+ }
+ assert(dout_len >= 0);
+ assert(dinp);
+
+ /*
+ * Copy command and data into output buffer so we can do a single I2C
+ * burst transaction.
+ */
+ ptr = dev->dout;
+
+ /*
+ * in_ptr starts of pointing to a dword-aligned input data buffer.
+ * We decrement it back by the number of header bytes we expect to
+ * receive, so that the first parameter of the resulting input data
+ * will be dword aligned.
+ */
+ in_ptr = dev->din + sizeof(int64_t);
+ if (!dev->cmd_version_is_supported) {
+ /* Send an old-style command */
+ *ptr++ = cmd;
+ out_bytes = dout_len + 1;
+ in_bytes = din_len + 2;
+ in_ptr--; /* Expect just a status byte */
+ } else {
+ *ptr++ = EC_CMD_VERSION0 + cmd_version;
+ *ptr++ = cmd;
+ *ptr++ = dout_len;
+ in_ptr -= 2; /* Expect status, length bytes */
+ }
+ memcpy(ptr, dout, dout_len);
+ ptr += dout_len;
+
+ if (dev->cmd_version_is_supported)
+ *ptr++ = (uint8_t)
+ cros_ec_calc_checksum(dev->dout, dout_len + 3);
+
+ /* Set to the proper i2c bus */
+ if (i2c_set_bus_num(dev->bus_num)) {
+ debug("%s: Cannot change to I2C bus %d\n", __func__,
+ dev->bus_num);
+ return -1;
+ }
+
+ /* Send output data */
+ cros_ec_dump_data("out", -1, dev->dout, out_bytes);
+ ret = i2c_write(dev->addr, 0, 0, dev->dout, out_bytes);
+ if (ret) {
+ debug("%s: Cannot complete I2C write to 0x%x\n",
+ __func__, dev->addr);
+ ret = -1;
+ }
+
+ if (!ret) {
+ ret = i2c_read(dev->addr, 0, 0, in_ptr, in_bytes);
+ if (ret) {
+ debug("%s: Cannot complete I2C read from 0x%x\n",
+ __func__, dev->addr);
+ ret = -1;
+ }
+ }
+
+ /* Return to original bus number */
+ i2c_set_bus_num(old_bus);
+ if (ret)
+ return ret;
+
+ if (*in_ptr != EC_RES_SUCCESS) {
+ debug("%s: Received bad result code %d\n", __func__, *in_ptr);
+ return -(int)*in_ptr;
+ }
+
+ if (dev->cmd_version_is_supported) {
+ int len, csum;
+
+ len = in_ptr[1];
+ if (len + 3 > sizeof(dev->din)) {
+ debug("%s: Received length %#02x too large\n",
+ __func__, len);
+ return -1;
+ }
+ csum = cros_ec_calc_checksum(in_ptr, 2 + len);
+ if (csum != in_ptr[2 + len]) {
+ debug("%s: Invalid checksum rx %#02x, calced %#02x\n",
+ __func__, in_ptr[2 + din_len], csum);
+ return -1;
+ }
+ din_len = min(din_len, len);
+ cros_ec_dump_data("in", -1, in_ptr, din_len + 3);
+ } else {
+ cros_ec_dump_data("in (old)", -1, in_ptr, in_bytes);
+ }
+
+ /* Return pointer to dword-aligned input data, if any */
+ *dinp = dev->din + sizeof(int64_t);
+
+ return din_len;
+}
+
+int cros_ec_i2c_decode_fdt(struct cros_ec_dev *dev, const void *blob)
+{
+ /* Decode interface-specific FDT params */
+ dev->max_frequency = fdtdec_get_int(blob, dev->node,
+ "i2c-max-frequency", 100000);
+ dev->bus_num = i2c_get_bus_num_fdt(dev->parent_node);
+ if (dev->bus_num == -1) {
+ debug("%s: Failed to read bus number\n", __func__);
+ return -1;
+ }
+ dev->addr = fdtdec_get_int(blob, dev->node, "reg", -1);
+ if (dev->addr == -1) {
+ debug("%s: Failed to read device address\n", __func__);
+ return -1;
+ }
+
+ return 0;
+}
+
+/**
+ * Initialize I2C protocol.
+ *
+ * @param dev CROS_EC device
+ * @param blob Device tree blob
+ * @return 0 if ok, -1 on error
+ */
+int cros_ec_i2c_init(struct cros_ec_dev *dev, const void *blob)
+{
+ i2c_init(dev->max_frequency, dev->addr);
+
+ dev->cmd_version_is_supported = 0;
+
+ return 0;
+}
--
1.8.1.3
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