This patch adds I2C support for carrying out the cros_ec protocol.
Signed-off-by: Randall Spangler rspangler@chromium.org Signed-off-by: Simon Glass sjg@chromium.org Signed-off-by: Hung-ying Tyan tyanh@chromium.org
--- Changes in v5: None Changes in v4: None 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; +}