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authorNico Huber <nico.huber@secunet.com>2017-08-01 17:09:35 +0200
committerMartin Roth <martinroth@google.com>2017-08-18 15:33:45 +0000
commit581738642fbeacdf97fc737a41b3128d72cf1a1c (patch)
tree8f40edb039a66fb6ccdc29b88f7e3b007b048e82 /src
parent0f2dd1eff9930e30dddd9aabceb5d85ee3b4e980 (diff)
downloadcoreboot-581738642fbeacdf97fc737a41b3128d72cf1a1c.tar.xz
Reinvent I2C ops
Do not use the global platform_i2c_transfer() function that can only be implemented by a single driver. Instead, make a `struct device` aware transfer() function the only interface function for I2C controller dri- vers to implement. To not force the slave device drivers to be implemented either above generic I2C or specialized SMBus operations, we support SMBus control- lers in the slave device interface too. We start with four simple slave functions: i2c_readb(), i2c_writeb(), i2c_readb_at() and i2c_writeb_at(). They are all compatible to respec- tive SMBus functions. But we keep aliases because it would be weird to force e.g. an I2C EEPROM driver to call smbus_read_byte(). Change-Id: I98386f91bf4799ba3df84ec8bc0f64edd4142818 Signed-off-by: Nico Huber <nico.huber@secunet.com> Reviewed-on: https://review.coreboot.org/20846 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Aaron Durbin <adurbin@chromium.org> Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Diffstat (limited to 'src')
-rw-r--r--src/device/Makefile.inc1
-rw-r--r--src/device/i2c.c83
-rw-r--r--src/device/i2c_bus.c161
-rw-r--r--src/include/device/i2c_bus.h82
-rw-r--r--src/include/device/smbus_def.h10
-rw-r--r--src/include/types.h9
-rw-r--r--src/soc/intel/common/block/i2c/i2c.c10
-rw-r--r--src/soc/intel/common/block/i2c/lpss_i2c.c15
-rw-r--r--src/soc/intel/common/block/i2c/lpss_i2c.h8
9 files changed, 267 insertions, 112 deletions
diff --git a/src/device/Makefile.inc b/src/device/Makefile.inc
index 8e6bf5be60..a1d592051b 100644
--- a/src/device/Makefile.inc
+++ b/src/device/Makefile.inc
@@ -37,3 +37,4 @@ bootblock-y += i2c.c
verstage-y += i2c.c
romstage-y += i2c.c
ramstage-y += i2c.c
+ramstage-y += i2c_bus.c
diff --git a/src/device/i2c.c b/src/device/i2c.c
index 6fdd5cff26..aa695caf03 100644
--- a/src/device/i2c.c
+++ b/src/device/i2c.c
@@ -13,92 +13,9 @@
* GNU General Public License for more details.
*/
-#include <device/device.h>
-#include <device/i2c_bus.h>
#include <device/i2c_simple.h>
#include <stdint.h>
-#if ENV_RAMSTAGE
-/* Return I2C operations for a bus */
-static inline const struct i2c_bus_operations *ops_i2c_bus(struct bus *bus)
-{
- if (bus && bus->dev && bus->dev->ops)
- return bus->dev->ops->ops_i2c_bus;
- return NULL;
-}
-
-int i2c_dev_find_bus(struct device *dev)
-{
- const struct i2c_bus_operations *ops;
- struct bus *pbus;
-
- if (!dev)
- return -1;
-
- /* Locate parent bus with I2C controller ops */
- pbus = dev->bus;
- while (pbus && pbus->dev && !ops_i2c_bus(pbus))
- if (pbus->dev->bus != pbus)
- pbus = pbus->dev->bus;
-
- /* Check if this I2C controller ops implements dev_to_bus() */
- ops = ops_i2c_bus(pbus);
- if (!ops || !ops->dev_to_bus)
- return -1;
-
- /* Use controller ops to determine the bus number */
- return ops->dev_to_bus(pbus->dev);
-}
-
-int i2c_dev_transfer(struct device *dev, struct i2c_msg *segments, int count)
-{
- int bus = i2c_dev_find_bus(dev);
- if (bus < 0)
- return -1;
- return i2c_transfer(bus, segments, count);
-}
-
-int i2c_dev_readb(struct device *dev, uint8_t reg, uint8_t *data)
-{
- int bus = i2c_dev_find_bus(dev);
- if (bus < 0)
- return -1;
- return i2c_readb(bus, dev->path.i2c.device, reg, data);
-}
-
-int i2c_dev_writeb(struct device *dev, uint8_t reg, uint8_t data)
-{
- int bus = i2c_dev_find_bus(dev);
- if (bus < 0)
- return -1;
- return i2c_writeb(bus, dev->path.i2c.device, reg, data);
-}
-
-int i2c_dev_read_bytes(struct device *dev, uint8_t reg, uint8_t *data, int len)
-{
- int bus = i2c_dev_find_bus(dev);
- if (bus < 0)
- return -1;
- return i2c_read_bytes(bus, dev->path.i2c.device, reg, data, len);
-}
-
-int i2c_dev_read_raw(struct device *dev, uint8_t *data, int len)
-{
- int bus = i2c_dev_find_bus(dev);
- if (bus < 0)
- return -1;
- return i2c_read_raw(bus, dev->path.i2c.device, data, len);
-}
-
-int i2c_dev_write_raw(struct device *dev, uint8_t *data, int len)
-{
- int bus = i2c_dev_find_bus(dev);
- if (bus < 0)
- return -1;
- return i2c_write_raw(bus, dev->path.i2c.device, data, len);
-}
-#endif
-
int i2c_read_field(unsigned bus, uint8_t chip, uint8_t reg, uint8_t *data,
uint8_t mask, uint8_t shift)
{
diff --git a/src/device/i2c_bus.c b/src/device/i2c_bus.c
new file mode 100644
index 0000000000..1c543efaba
--- /dev/null
+++ b/src/device/i2c_bus.c
@@ -0,0 +1,161 @@
+/*
+ * This file is part of the coreboot 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; version 2 of the License.
+ *
+ * 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.
+ */
+
+#include <stdlib.h>
+#include <stdint.h>
+#include <console/console.h>
+#include <device/smbus.h>
+#include <device/i2c_bus.h>
+
+struct bus *i2c_link(struct device *const dev)
+{
+ if (!dev || !dev->bus)
+ return NULL;
+
+ struct bus *link = dev->bus;
+ while (link) {
+ struct device *const parent = link->dev;
+
+ if (parent && parent->ops &&
+ (parent->ops->ops_i2c_bus || parent->ops->ops_smbus_bus))
+ break;
+
+ if (parent && parent->bus)
+ link = parent->bus;
+ else
+ link = NULL;
+ }
+
+ if (!link) {
+ printk(BIOS_ALERT, "%s Cannot find I2C or SMBus bus operations",
+ dev_path(dev));
+ }
+
+ return link;
+}
+
+int i2c_readb(struct device *const dev)
+{
+ struct device *const busdev = i2c_busdev(dev);
+ if (!busdev)
+ return -1;
+
+ if (busdev->ops->ops_i2c_bus) {
+ uint8_t val;
+ const struct i2c_msg msg = {
+ .flags = I2C_M_RD,
+ .slave = dev->path.i2c.device,
+ .buf = &val,
+ .len = sizeof(val),
+ };
+
+ const int ret = busdev->ops->ops_i2c_bus->
+ transfer(busdev, &msg, 1);
+ if (ret)
+ return ret;
+ else
+ return val;
+ } else if (busdev->ops->ops_smbus_bus->recv_byte) {
+ return busdev->ops->ops_smbus_bus->recv_byte(dev);
+ } else {
+ printk(BIOS_ERR, "%s Missing ops_smbus_bus->recv_byte",
+ dev_path(busdev));
+ return -1;
+ }
+}
+
+int i2c_writeb(struct device *const dev, uint8_t val)
+{
+ struct device *const busdev = i2c_busdev(dev);
+ if (!busdev)
+ return -1;
+
+ if (busdev->ops->ops_i2c_bus) {
+ const struct i2c_msg msg = {
+ .flags = 0,
+ .slave = dev->path.i2c.device,
+ .buf = &val,
+ .len = sizeof(val),
+ };
+ return busdev->ops->ops_i2c_bus->transfer(busdev, &msg, 1);
+ } else if (busdev->ops->ops_smbus_bus->send_byte) {
+ return busdev->ops->ops_smbus_bus->send_byte(dev, val);
+ } else {
+ printk(BIOS_ERR, "%s Missing ops_smbus_bus->send_byte",
+ dev_path(busdev));
+ return -1;
+ }
+}
+
+int i2c_readb_at(struct device *const dev, uint8_t off)
+{
+ struct device *const busdev = i2c_busdev(dev);
+ if (!busdev)
+ return -1;
+
+ if (busdev->ops->ops_i2c_bus) {
+ uint8_t val;
+ const struct i2c_msg msg[] = {
+ {
+ .flags = 0,
+ .slave = dev->path.i2c.device,
+ .buf = &off,
+ .len = sizeof(off),
+ },
+ {
+ .flags = I2C_M_RD,
+ .slave = dev->path.i2c.device,
+ .buf = &val,
+ .len = sizeof(val),
+ },
+ };
+
+ const int ret = busdev->ops->ops_i2c_bus->
+ transfer(busdev, msg, ARRAY_SIZE(msg));
+ if (ret)
+ return ret;
+ else
+ return val;
+ } else if (busdev->ops->ops_smbus_bus->read_byte) {
+ return busdev->ops->ops_smbus_bus->read_byte(dev, off);
+ } else {
+ printk(BIOS_ERR, "%s Missing ops_smbus_bus->read_byte",
+ dev_path(busdev));
+ return -1;
+ }
+}
+
+int i2c_writeb_at(struct device *const dev,
+ const uint8_t off, const uint8_t val)
+{
+ struct device *const busdev = i2c_busdev(dev);
+ if (!busdev)
+ return -1;
+
+ if (busdev->ops->ops_i2c_bus) {
+ uint8_t buf[] = { off, val };
+ const struct i2c_msg msg = {
+ .flags = 0,
+ .slave = dev->path.i2c.device,
+ .buf = buf,
+ .len = sizeof(buf),
+ };
+ return busdev->ops->ops_i2c_bus->transfer(busdev, &msg, 1);
+ } else if (busdev->ops->ops_smbus_bus->write_byte) {
+ return busdev->ops->ops_smbus_bus->write_byte(dev, off, val);
+ } else {
+ printk(BIOS_ERR, "%s Missing ops_smbus_bus->write_byte",
+ dev_path(busdev));
+ return -1;
+ }
+}
diff --git a/src/include/device/i2c_bus.h b/src/include/device/i2c_bus.h
index 474d9e5b2c..f1416a7411 100644
--- a/src/include/device/i2c_bus.h
+++ b/src/include/device/i2c_bus.h
@@ -1,8 +1,6 @@
/*
* This file is part of the coreboot project.
*
- * Copyright (C) 2014 Google, Inc.
- *
* 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; version 2 of the License.
@@ -16,29 +14,79 @@
#ifndef _DEVICE_I2C_BUS_H_
#define _DEVICE_I2C_BUS_H_
+#include <stdlib.h>
#include <stdint.h>
#include <device/i2c.h>
#include <device/device.h>
/* I2C bus operation for ramstage drivers */
struct i2c_bus_operations {
- /*
- * This is an SOC specific method that can be provided to translate the
- * 'struct device' for an I2C controller into a unique I2C bus number.
- * Returns -1 if the bus number for this device cannot be determined.
- */
- int (*dev_to_bus)(struct device *dev);
+ int (*transfer)(struct device *, const struct i2c_msg *, size_t count);
};
-/* Return I2C bus number for provided device, -1 if not found */
-int i2c_dev_find_bus(struct device *dev);
+/*
+ * Returns the first upstream facing link whose bus implements either
+ * `i2c_bus_operations` *or* `smbus_bus_operations`.
+ *
+ * If not NULL, guarantees that `->dev`, `->dev->ops` and either
+ * `->dev->ops->ops_i2c_bus` or `->dev->ops->ops_smbus_bus` are
+ * not NULL.
+ */
+struct bus *i2c_link(struct device *);
+
+/*
+ * Shorthand for `i2c_link(dev)->dev`.
+ *
+ * Returns NULL if i2c_link(dev) returns NULL.
+ */
+static inline struct device *i2c_busdev(struct device *dev)
+{
+ struct bus *const link = i2c_link(dev);
+ return link ? link->dev : NULL;
+}
+
+/*
+ * Slave driver interface functions. These will look for the next
+ * `i2c_bus_operations` *or* `smbus_bus_operations` and perform the
+ * respective transfers.
+ *
+ * The interface is limited to what current slave drivers demand.
+ * Extend as required.
+ *
+ * All functions return a negative `enum cb_err` value on error.
+ * Either CB_ERR, CB_ERR_ARG or any CB_I2C_* (cf. include/types.h).
+ */
+
+/*
+ * Reads one byte.
+ * Compatible to smbus_recv_byte().
+ *
+ * Returns the read byte on success, negative `enum cb_err` value on error.
+ */
+int i2c_readb(struct device *);
+
+/*
+ * Writes the byte `val`.
+ * Compatible to smbus_send_byte().
+ *
+ * Returns 0 on success, negative `enum cb_err` value on error.
+ */
+int i2c_writeb(struct device *, uint8_t val);
-/* Variants of I2C helper functions that take a device instead of bus number */
-int i2c_dev_transfer(struct device *dev, struct i2c_msg *segments, int count);
-int i2c_dev_readb(struct device *dev, uint8_t reg, uint8_t *data);
-int i2c_dev_writeb(struct device *dev, uint8_t reg, uint8_t data);
-int i2c_dev_read_bytes(struct device *dev, uint8_t reg, uint8_t *data, int len);
-int i2c_dev_read_raw(struct device *dev, uint8_t *data, int len);
-int i2c_dev_write_raw(struct device *dev, uint8_t *data, int len);
+/*
+ * Sends the register offset `off` and reads one byte.
+ * Compatible to smbus_read_byte().
+ *
+ * Returns the read byte on success, negative `enum cb_err` value on error.
+ */
+int i2c_readb_at(struct device *, uint8_t off);
+
+/*
+ * Sends the register offset `off` followed by the byte `val`.
+ * Compatible to smbus_write_byte().
+ *
+ * Returns 0 on success, negative `enum cb_err` value on error.
+ */
+int i2c_writeb_at(struct device *, uint8_t off, uint8_t val);
#endif /* _DEVICE_I2C_BUS_H_ */
diff --git a/src/include/device/smbus_def.h b/src/include/device/smbus_def.h
index 0b07400b37..61d786107b 100644
--- a/src/include/device/smbus_def.h
+++ b/src/include/device/smbus_def.h
@@ -1,10 +1,12 @@
#ifndef DEVICE_SMBUS_DEF_H
#define DEVICE_SMBUS_DEF_H
+#include <types.h>
+
/* Error results are negative success is >= 0 */
-#define SMBUS_ERROR -1
-#define SMBUS_WAIT_UNTIL_READY_TIMEOUT -2
-#define SMBUS_WAIT_UNTIL_DONE_TIMEOUT -3
-#define SMBUS_WAIT_UNTIL_ACTIVE_TIMEOUT -4
+#define SMBUS_ERROR CB_ERR
+#define SMBUS_WAIT_UNTIL_READY_TIMEOUT CB_I2C_BUSY
+#define SMBUS_WAIT_UNTIL_DONE_TIMEOUT CB_I2C_TIMEOUT
+#define SMBUS_WAIT_UNTIL_ACTIVE_TIMEOUT CB_I2C_NO_DEVICE
#endif /* DEVICE_SMBUS_DEF_H */
diff --git a/src/include/types.h b/src/include/types.h
index df0947370f..7307cd5072 100644
--- a/src/include/types.h
+++ b/src/include/types.h
@@ -47,7 +47,14 @@ enum cb_err {
/* Keyboard test failures */
CB_KBD_CONTROLLER_FAILURE = -200,
- CB_KBD_INTERFACE_FAILURE = -201
+ CB_KBD_INTERFACE_FAILURE = -201,
+
+ /* I2C controller failures */
+ CB_I2C_NO_DEVICE = -300, /**< Device is not responding */
+ CB_I2C_BUSY = -301, /**< Device tells it's busy */
+ CB_I2C_PROTOCOL_ERROR = -302, /**< Data lost or spurious slave
+ device response, try again? */
+ CB_I2C_TIMEOUT = -303, /**< Transmission timed out */
};
#endif /* __TYPES_H */
diff --git a/src/soc/intel/common/block/i2c/i2c.c b/src/soc/intel/common/block/i2c/i2c.c
index aeb6d8f2ed..625bb991d4 100644
--- a/src/soc/intel/common/block/i2c/i2c.c
+++ b/src/soc/intel/common/block/i2c/i2c.c
@@ -150,8 +150,14 @@ static void lpss_i2c_acpi_fill_ssdt(struct device *dev)
acpigen_pop_len();
}
-static struct i2c_bus_operations i2c_bus_ops = {
- .dev_to_bus = &lpss_i2c_dev_to_bus,
+static int lpss_i2c_dev_transfer(struct device *dev,
+ const struct i2c_msg *msg, size_t count)
+{
+ return lpss_i2c_transfer(lpss_i2c_dev_to_bus(dev), msg, count);
+}
+
+static const struct i2c_bus_operations i2c_bus_ops = {
+ .transfer = lpss_i2c_dev_transfer,
};
static struct device_operations i2c_dev_ops = {
diff --git a/src/soc/intel/common/block/i2c/lpss_i2c.c b/src/soc/intel/common/block/i2c/lpss_i2c.c
index 868a6ad300..7db3fe9668 100644
--- a/src/soc/intel/common/block/i2c/lpss_i2c.c
+++ b/src/soc/intel/common/block/i2c/lpss_i2c.c
@@ -258,7 +258,7 @@ static int lpss_i2c_wait_for_bus_idle(struct lpss_i2c_regs *regs)
/* Transfer one byte of one segment, sending stop bit if requested */
static int lpss_i2c_transfer_byte(struct lpss_i2c_regs *regs,
- struct i2c_msg *segment,
+ const struct i2c_msg *segment,
size_t byte, int send_stop)
{
struct stopwatch sw;
@@ -297,16 +297,15 @@ static int lpss_i2c_transfer_byte(struct lpss_i2c_regs *regs,
return 0;
}
-/* Global I2C bus handler, defined in include/i2c.h */
-int platform_i2c_transfer(unsigned int bus, struct i2c_msg *segments,
- int count)
+int lpss_i2c_transfer(unsigned int bus,
+ const struct i2c_msg *segments, size_t count)
{
struct stopwatch sw;
struct lpss_i2c_regs *regs;
size_t byte;
int ret = -1;
- if (count <= 0 || !segments)
+ if (count == 0 || !segments)
return -1;
regs = (struct lpss_i2c_regs *)lpss_i2c_base_address(bus);
@@ -396,6 +395,12 @@ out:
return ret;
}
+/* Global I2C bus handler, defined in include/device/i2c_simple.h */
+int platform_i2c_transfer(unsigned int bus, struct i2c_msg *msg, int count)
+{
+ return lpss_i2c_transfer(bus, msg, count < 0 ? 0 : count);
+}
+
static int lpss_i2c_set_speed_config(unsigned int bus,
const struct lpss_i2c_speed_config *config)
{
diff --git a/src/soc/intel/common/block/i2c/lpss_i2c.h b/src/soc/intel/common/block/i2c/lpss_i2c.h
index 2cb3d5ed52..72341621c0 100644
--- a/src/soc/intel/common/block/i2c/lpss_i2c.h
+++ b/src/soc/intel/common/block/i2c/lpss_i2c.h
@@ -89,3 +89,11 @@ int lpss_i2c_gen_speed_config(struct lpss_i2c_regs *regs,
enum i2c_speed speed,
const struct lpss_i2c_bus_config *bcfg,
struct lpss_i2c_speed_config *config);
+
+/*
+ * Process given I2C segments in a single transfer
+ * Return value:
+ * -1 = failure
+ * 0 = success
+ */
+int lpss_i2c_transfer(unsigned int bus, const struct i2c_msg *, size_t count);