Add a driver to support the special LDO access used by spring. This is a custom method in the cros_ec protocol - it does not use an I2C pass-through.
There are two implementation choices:
1. Write a special LDO driver which can talk across the EC. Duplicate all the logic from TPS65090 for retrying when the LDO fails to come up.
2. Write a special I2C bus driver which pretends to be a TPS65090 and transfers reads and writes using the LDO message.
Either is distasteful. The latter method is chosen since it results in less code duplication and a fairly simple (30-line) implementation of the core logic.
The crosec 'ldo' subcommand could be removed (since i2c md/mw will work instead) but is retained as a convenience.
Signed-off-by: Simon Glass sjg@chromium.org ---
Changes in v2: None
drivers/i2c/Kconfig | 13 ++++++++ drivers/i2c/Makefile | 1 + drivers/i2c/cros_ec_ldo.c | 77 +++++++++++++++++++++++++++++++++++++++++++++++ drivers/misc/cros_ec.c | 21 +++++++------ include/cros_ec.h | 4 +-- 5 files changed, 104 insertions(+), 12 deletions(-) create mode 100644 drivers/i2c/cros_ec_ldo.c
diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig index e861b53..9a62ddd 100644 --- a/drivers/i2c/Kconfig +++ b/drivers/i2c/Kconfig @@ -29,6 +29,19 @@ config I2C_CROS_EC_TUNNEL I2C or LPC). Some Chromebooks use this when the hardware design does not allow direct access to the main PMIC from the AP.
+config I2C_CROS_EC_LDO + bool "Provide access to LDOs on the Chrome OS EC" + depends on CROS_EC + ---help--- + On many Chromebooks the main PMIC is inaccessible to the AP. This is + often dealt with by using an I2C pass-through interface provided by + the EC. On some unfortunate models (e.g. Spring) the pass-through + is not available, and an LDO message is available instead. This + option enables a driver which provides very basic access to those + regulators, via the EC. We implement this as an I2C bus which + emulates just the TPS65090 messages we know about. This is done to + avoid duplicating the logic in the TPS65090 regulator driver for + enabling/disabling an LDO.
config DM_I2C_GPIO bool "Enable Driver Model for software emulated I2C bus driver" diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile index 7f01fce..9b45248 100644 --- a/drivers/i2c/Makefile +++ b/drivers/i2c/Makefile @@ -8,6 +8,7 @@ obj-$(CONFIG_DM_I2C) += i2c-uclass.o obj-$(CONFIG_DM_I2C_COMPAT) += i2c-uclass-compat.o obj-$(CONFIG_DM_I2C_GPIO) += i2c-gpio.o obj-$(CONFIG_I2C_CROS_EC_TUNNEL) += cros_ec_tunnel.o +obj-$(CONFIG_I2C_CROS_EC_LDO) += cros_ec_ldo.o
obj-$(CONFIG_SYS_I2C_ADI) += adi_i2c.o obj-$(CONFIG_I2C_MV) += mv_i2c.o diff --git a/drivers/i2c/cros_ec_ldo.c b/drivers/i2c/cros_ec_ldo.c new file mode 100644 index 0000000..b817c61 --- /dev/null +++ b/drivers/i2c/cros_ec_ldo.c @@ -0,0 +1,77 @@ +/* + * Copyright (c) 2015 Google, Inc + * Written by Simon Glass sjg@chromium.org + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <dm.h> +#include <cros_ec.h> +#include <errno.h> +#include <i2c.h> +#include <power/tps65090.h> + +static int cros_ec_ldo_set_bus_speed(struct udevice *dev, unsigned int speed) +{ + return 0; +} + +static int cros_ec_ldo_xfer(struct udevice *dev, struct i2c_msg *msg, + int nmsgs) +{ + bool is_read = nmsgs > 1; + int fet_id, ret; + + /* + * Look for reads and writes of the LDO registers. In either case the + * first message is a write with the register number as the first byte. + */ + if (!nmsgs || !msg->len || (msg->flags & I2C_M_RD)) { + debug("%s: Invalid message\n", __func__); + goto err; + } + + fet_id = msg->buf[0] - REG_FET_BASE; + if (fet_id < 1 || fet_id > MAX_FET_NUM) { + debug("%s: Invalid FET %d\n", __func__, fet_id); + goto err; + } + + if (is_read) { + uint8_t state; + + ret = cros_ec_get_ldo(dev->parent, fet_id, &state); + if (!ret) + msg[1].buf[0] = state ? + FET_CTRL_ENFET | FET_CTRL_PGFET : 0; + } else { + bool on = msg->buf[1] & FET_CTRL_ENFET; + + ret = cros_ec_set_ldo(dev->parent, fet_id, on); + } + + return ret; + +err: + /* Indicate that the message is unimplemented */ + return -ENOSYS; +} + +static const struct dm_i2c_ops cros_ec_i2c_ops = { + .xfer = cros_ec_ldo_xfer, + .set_bus_speed = cros_ec_ldo_set_bus_speed, +}; + +static const struct udevice_id cros_ec_i2c_ids[] = { + { .compatible = "google,cros-ec-ldo-tunnel" }, + { } +}; + +U_BOOT_DRIVER(cros_ec_ldo) = { + .name = "cros_ec_ldo_tunnel", + .id = UCLASS_I2C, + .of_match = cros_ec_i2c_ids, + .per_child_auto_alloc_size = sizeof(struct dm_i2c_chip), + .ops = &cros_ec_i2c_ops, +}; diff --git a/drivers/misc/cros_ec.c b/drivers/misc/cros_ec.c index ae52561..6027177 100644 --- a/drivers/misc/cros_ec.c +++ b/drivers/misc/cros_ec.c @@ -931,31 +931,32 @@ int cros_ec_write_vbnvcontext(struct cros_ec_dev *dev, const uint8_t *block) return 0; }
-int cros_ec_set_ldo(struct cros_ec_dev *dev, uint8_t index, uint8_t state) +int cros_ec_set_ldo(struct udevice *dev, uint8_t index, uint8_t state) { + struct cros_ec_dev *cdev = dev_get_uclass_priv(dev); struct ec_params_ldo_set params;
params.index = index; params.state = state;
- if (ec_command_inptr(dev, EC_CMD_LDO_SET, 0, - ¶ms, sizeof(params), - NULL, 0)) + if (ec_command_inptr(cdev, EC_CMD_LDO_SET, 0, ¶ms, sizeof(params), + NULL, 0)) return -1;
return 0; }
-int cros_ec_get_ldo(struct cros_ec_dev *dev, uint8_t index, uint8_t *state) +int cros_ec_get_ldo(struct udevice *dev, uint8_t index, uint8_t *state) { + struct cros_ec_dev *cdev = dev_get_uclass_priv(dev); struct ec_params_ldo_get params; struct ec_response_ldo_get *resp;
params.index = index;
- if (ec_command_inptr(dev, EC_CMD_LDO_GET, 0, - ¶ms, sizeof(params), - (uint8_t **)&resp, sizeof(*resp)) != sizeof(*resp)) + if (ec_command_inptr(cdev, EC_CMD_LDO_GET, 0, ¶ms, sizeof(params), + (uint8_t **)&resp, sizeof(*resp)) != + sizeof(*resp)) return -1;
*state = resp->state; @@ -1681,9 +1682,9 @@ static int do_cros_ec(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) state = simple_strtoul(argv[3], &endp, 10); if (*argv[3] == 0 || *endp != 0) return CMD_RET_USAGE; - ret = cros_ec_set_ldo(dev, index, state); + ret = cros_ec_set_ldo(udev, index, state); } else { - ret = cros_ec_get_ldo(dev, index, &state); + ret = cros_ec_get_ldo(udev, index, &state); if (!ret) { printf("LDO%d: %s\n", index, state == EC_LDO_STATE_ON ? diff --git a/include/cros_ec.h b/include/cros_ec.h index 41951c3..0ad9d81 100644 --- a/include/cros_ec.h +++ b/include/cros_ec.h @@ -350,7 +350,7 @@ int cros_ec_read_build_info(struct cros_ec_dev *dev, char **strp); * @param state new state of the LDO/FET : EC_LDO_STATE_ON|OFF * @return 0 if ok, -1 on error */ -int cros_ec_set_ldo(struct cros_ec_dev *dev, uint8_t index, uint8_t state); +int cros_ec_set_ldo(struct udevice *dev, uint8_t index, uint8_t state);
/** * Read back a LDO / FET current state. @@ -360,7 +360,7 @@ int cros_ec_set_ldo(struct cros_ec_dev *dev, uint8_t index, uint8_t state); * @param state current state of the LDO/FET : EC_LDO_STATE_ON|OFF * @return 0 if ok, -1 on error */ -int cros_ec_get_ldo(struct cros_ec_dev *dev, uint8_t index, uint8_t *state); +int cros_ec_get_ldo(struct udevice *dev, uint8_t index, uint8_t *state);
/** * Get access to the error reported when cros_ec_board_init() was called