+Masahiro On Nov 24, 2014 11:58 AM, "Simon Glass" <[email protected]> wrote:
> The uclass implements the same operations as the current I2C framework but > makes some changes to make it fit driver model better: > > - Remove the chip address from API calls > - Remove the address length from API calls > - Remove concept of 'current' I2C bus > - Drop all existing init functions > > Signed-off-by: Simon Glass <[email protected]> > --- > > Changes in v3: > - Change uclass <=> driver API to use a message list > - Correct bogus address len code (was confused with chip address length) > - Drop extra call to i2c_bind_driver() in i2c_probe() > - Add a helper to query chip flags > - Add support for reading a byte at a time with an address for each byte > > Changes in v2: > - Fix cihp typo > - Implement generic I2C devices to allow 'i2c probe' on unknown devices > - Return the probed device from i2c_probe() > - Set the bus speed after the bus is probed > - Add some debugging for generic I2C device binding > - Add a 'deblock' method to recover an I2C bus stuck in mid-transaction > - Add a helper function to find a chip on a particular bus number > > drivers/i2c/Makefile | 1 + > drivers/i2c/i2c-uclass.c | 411 > +++++++++++++++++++++++++++++++++++++++++++++ > include/config_fallbacks.h | 6 + > include/dm/uclass-id.h | 2 + > include/i2c.h | 348 ++++++++++++++++++++++++++++++++++++++ > 5 files changed, 768 insertions(+) > create mode 100644 drivers/i2c/i2c-uclass.c > > diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile > index dae3d71..063e097 100644 > --- a/drivers/i2c/Makefile > +++ b/drivers/i2c/Makefile > @@ -4,6 +4,7 @@ > # > # SPDX-License-Identifier: GPL-2.0+ > # > +obj-$(CONFIG_DM_I2C) += i2c-uclass.o > > obj-$(CONFIG_SYS_I2C_ADI) += adi_i2c.o > obj-$(CONFIG_I2C_MV) += mv_i2c.o > diff --git a/drivers/i2c/i2c-uclass.c b/drivers/i2c/i2c-uclass.c > new file mode 100644 > index 0000000..4063a80 > --- /dev/null > +++ b/drivers/i2c/i2c-uclass.c > @@ -0,0 +1,411 @@ > +/* > + * Copyright (c) 2014 Google, Inc > + * > + * SPDX-License-Identifier: GPL-2.0+ > + */ > + > +#include <common.h> > +#include <dm.h> > +#include <errno.h> > +#include <fdtdec.h> > +#include <i2c.h> > +#include <malloc.h> > +#include <dm/device-internal.h> > +#include <dm/lists.h> > +#include <dm/root.h> > + > +DECLARE_GLOBAL_DATA_PTR; > + > +static bool i2c_setup_offset(struct dm_i2c_chip *chip, uint offset, > + uint8_t offset_buf[], struct i2c_msg *msg) > +{ > + if (!chip->offset_len) > + return false; > + msg->addr = chip->chip_addr; > + msg->flags = chip->flags; > + msg->len = chip->offset_len; > + msg->buf = offset_buf; > + offset_buf[0] = offset; > + offset_buf[1] = offset >> 8; > + offset_buf[2] = offset >> 16; > + offset_buf[3] = offset >> 24; > + > + return true; > +} > + > +static int i2c_read_bytewise(struct udevice *dev, uint offset, > + const uint8_t *buffer, int len) > +{ > + struct dm_i2c_chip *chip = dev_get_parentdata(dev); > + struct udevice *bus = dev_get_parent(dev); > + struct dm_i2c_ops *ops = i2c_get_ops(bus); > + struct i2c_msg msg[1]; > + uint8_t buf[5]; > + int ret; > + int i; > + > + for (i = 0; i < len; i++) { > + i2c_setup_offset(chip, offset, buf, msg); > + msg->len++; > + buf[chip->offset_len] = buffer[i]; > + > + ret = ops->xfer(bus, msg, 1); > + if (ret) > + return ret; > + } > + > + return 0; > +} > + > +int i2c_read(struct udevice *dev, uint offset, uint8_t *buffer, int len) > +{ > + struct dm_i2c_chip *chip = dev_get_parentdata(dev); > + struct udevice *bus = dev_get_parent(dev); > + struct dm_i2c_ops *ops = i2c_get_ops(bus); > + struct i2c_msg msg[2], *ptr; > + uint8_t offset_buf[4]; > + int msg_count; > + > + if (!ops->xfer) > + return -ENOSYS; > + if (chip->flags & DM_I2C_CHIP_RE_ADDRESS) > + return i2c_read_bytewise(dev, offset, buffer, len); > + ptr = msg; > + if (i2c_setup_offset(chip, offset, offset_buf, ptr)) > + ptr++; > + > + if (len) { > + ptr->addr = chip->chip_addr; > + ptr->flags = chip->flags | I2C_M_RD; > + ptr->len = len; > + ptr->buf = buffer; > + ptr++; > + } > + msg_count = ptr - msg; > + > + return ops->xfer(bus, msg, msg_count); > +} > + > +int i2c_write(struct udevice *dev, uint offset, const uint8_t *buffer, > int len) > +{ > + struct dm_i2c_chip *chip = dev_get_parentdata(dev); > + struct udevice *bus = dev_get_parent(dev); > + struct dm_i2c_ops *ops = i2c_get_ops(bus); > + struct i2c_msg msg[1]; > + > + if (!ops->xfer) > + return -ENOSYS; > + > + /* > + * The simple approach would be to send two messages here: one to > + * set the offset and one to write the bytes. However some drivers > + * will not be expecting this, and some chips won't like how the > + * driver presents this on the I2C bus. > + * > + * The API does not support separate offset and data. We could > extend > + * it with a flag indicating that there is data in the next message > + * that needs to be processed in the same transaction. We could > + * instead add an additional buffer to each message. For now, > handle > + * this in the uclass since it isn't clear what the impact on > drivers > + * would be with this extra complication. Unfortunately this means > + * copying the message. > + * > + * Use the stack for small messages, malloc() for larger ones. We > + * need to allow space for the offset (up to 4 bytes) and the > message > + * itself. > + */ > + if (len < 64) { > + uint8_t buf[4 + len]; > + > + i2c_setup_offset(chip, offset, buf, msg); > + msg->len += len; > + memcpy(buf + chip->offset_len, buffer, len); > + > + return ops->xfer(bus, msg, 1); > + } else { > + uint8_t *buf; > + int ret; > + > + buf = malloc(4 + len); > + if (!buf) > + return -ENOMEM; > + i2c_setup_offset(chip, offset, buf, msg); > + msg->len += len; > + memcpy(buf + chip->offset_len, buffer, len); > + > + ret = ops->xfer(bus, msg, 1); > + free(buf); > + return ret; > + } > +} > + > +static int i2c_probe_chip(struct udevice *bus, uint chip_addr) > +{ > + struct dm_i2c_ops *ops = i2c_get_ops(bus); > + struct i2c_msg msg[1]; > + uint8_t ch = 0; > + > + if (!ops->xfer) > + return -ENOSYS; > + > + msg->addr = chip_addr; > + msg->flags = 0; > + msg->len = 1; > + msg->buf = &ch; > + > + return ops->xfer(bus, msg, 1); > +} > + > +static int i2c_bind_driver(struct udevice *bus, uint chip_addr, > + struct udevice **devp) > +{ > + struct dm_i2c_chip *chip; > + char name[30], *str; > + struct udevice *dev; > + int ret; > + > + snprintf(name, sizeof(name), "generic_%x", chip_addr); > + str = strdup(name); > + ret = device_bind_driver(bus, "i2c_generic_drv", str, &dev); > + debug("%s: device_bind_driver: ret=%d\n", __func__, ret); > + if (ret) > + goto err_bind; > + > + /* Tell the device what we know about it */ > + chip = calloc(1, sizeof(struct dm_i2c_chip)); > + if (!chip) { > + ret = -ENOMEM; > + goto err_mem; > + } > + chip->chip_addr = chip_addr; > + chip->offset_len = 1; /* we assume */ > + ret = device_probe_child(dev, chip); > + debug("%s: device_probe_child: ret=%d\n", __func__, ret); > + free(chip); > + if (ret) > + goto err_probe; > + > + *devp = dev; > + return 0; > + > +err_probe: > +err_mem: > + device_unbind(dev); > +err_bind: > + free(str); > + return ret; > +} > + > +int i2c_get_chip(struct udevice *bus, uint chip_addr, struct udevice > **devp) > +{ > + struct udevice *dev; > + > + debug("%s: Searching bus '%s' for address %02x: ", __func__, > + bus->name, chip_addr); > + for (device_find_first_child(bus, &dev); dev; > + device_find_next_child(&dev)) { > + struct dm_i2c_chip store; > + struct dm_i2c_chip *chip = dev_get_parentdata(dev); > + int ret; > + > + if (!chip) { > + chip = &store; > + i2c_chip_ofdata_to_platdata(gd->fdt_blob, > + dev->of_offset, chip); > + } > + if (chip->chip_addr == chip_addr) { > + ret = device_probe(dev); > + debug("found, ret=%d\n", ret); > + if (ret) > + return ret; > + *devp = dev; > + return 0; > + } > + } > + debug("not found\n"); > + return i2c_bind_driver(bus, chip_addr, devp); > +} > + > +int i2c_get_chip_for_busnum(int busnum, int chip_addr, struct udevice > **devp) > +{ > + struct udevice *bus; > + int ret; > + > + ret = uclass_get_device_by_seq(UCLASS_I2C, busnum, &bus); > + if (ret) { > + debug("Cannot find I2C bus %d\n", busnum); > + return ret; > + } > + ret = i2c_get_chip(bus, chip_addr, devp); > + if (ret) { > + debug("Cannot find I2C chip %02x on bus %d\n", chip_addr, > + busnum); > + return ret; > + } > + > + return 0; > +} > + > +int i2c_probe(struct udevice *bus, uint chip_addr, struct udevice **devp) > +{ > + int ret; > + > + *devp = NULL; > + > + /* First probe that chip */ > + ret = i2c_probe_chip(bus, chip_addr); > + debug("%s: bus='%s', address %02x, ret=%d\n", __func__, bus->name, > + chip_addr, ret); > + if (ret) > + return ret; > + > + /* The chip was found, see if we have a driver, and probe it */ > + ret = i2c_get_chip(bus, chip_addr, devp); > + debug("%s: i2c_get_chip: ret=%d\n", __func__, ret); > + > + return ret; > +} > + > +int i2c_set_bus_speed(struct udevice *bus, unsigned int speed) > +{ > + struct dm_i2c_ops *ops = i2c_get_ops(bus); > + struct dm_i2c_bus *i2c = bus->uclass_priv; > + int ret; > + > + if (ops->set_bus_speed) { > + ret = ops->set_bus_speed(bus, speed); > + if (ret) > + return ret; > + } > + i2c->speed_hz = speed; > + > + return 0; > +} > + > +/* > + * i2c_get_bus_speed: > + * > + * Returns speed of selected I2C bus in Hz > + */ > +int i2c_get_bus_speed(struct udevice *bus) > +{ > + struct dm_i2c_ops *ops = i2c_get_ops(bus); > + struct dm_i2c_bus *i2c = bus->uclass_priv; > + > + if (!ops->set_bus_speed) > + return i2c->speed_hz; > + > + return ops->get_bus_speed(bus); > +} > + > +int i2c_set_chip_flags(struct udevice *dev, uint flags) > +{ > + struct udevice *bus = dev->parent; > + struct dm_i2c_chip *chip = dev_get_parentdata(dev); > + struct dm_i2c_ops *ops = i2c_get_ops(bus); > + int ret; > + > + if (ops->set_flags) { > + ret = ops->set_flags(dev, flags); > + if (ret) > + return ret; > + } > + chip->flags = flags; > + > + return 0; > +} > + > +int i2c_get_chip_flags(struct udevice *dev, uint *flagsp) > +{ > + struct dm_i2c_chip *chip = dev_get_parentdata(dev); > + > + *flagsp = chip->flags; > + > + return 0; > +} > + > +int i2c_set_chip_offset_len(struct udevice *dev, uint offset_len) > +{ > + struct udevice *bus = dev->parent; > + struct dm_i2c_chip *chip = dev_get_parentdata(dev); > + struct dm_i2c_ops *ops = i2c_get_ops(bus); > + int ret; > + > + if (offset_len > 3) > + return -EINVAL; > + if (ops->set_offset_len) { > + ret = ops->set_offset_len(dev, offset_len); > + if (ret) > + return ret; > + } > + chip->offset_len = offset_len; > + > + return 0; > +} > + > +int i2c_deblock(struct udevice *bus) > +{ > + struct dm_i2c_ops *ops = i2c_get_ops(bus); > + > + /* > + * We could implement a software deblocking here if we could get > + * access to the GPIOs used by I2C, and switch them to GPIO mode > + * and then back to I2C. This is somewhat beyond our powers in > + * driver model at present, so for now just fail. > + * > + * See https://patchwork.ozlabs.org/patch/399040/ > + */ > + if (!ops->deblock) > + return -ENOSYS; > + > + return ops->deblock(bus); > +} > + > +int i2c_chip_ofdata_to_platdata(const void *blob, int node, > + struct dm_i2c_chip *chip) > +{ > + chip->offset_len = 1; /* default */ > + chip->flags = 0; > + chip->chip_addr = fdtdec_get_int(gd->fdt_blob, node, "reg", -1); > + if (chip->chip_addr == -1) { > + debug("%s: I2C Node '%s' has no 'reg' property\n", > __func__, > + fdt_get_name(blob, node, NULL)); > + return -EINVAL; > + } > + > + return 0; > +} > + > +static int i2c_post_probe(struct udevice *dev) > +{ > + struct dm_i2c_bus *i2c = dev->uclass_priv; > + > + i2c->speed_hz = fdtdec_get_int(gd->fdt_blob, dev->of_offset, > + "clock-frequency", 100000); > + > + return i2c_set_bus_speed(dev, i2c->speed_hz); > +} > + > +int i2c_post_bind(struct udevice *dev) > +{ > + /* Scan the bus for devices */ > + return dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, false); > +} > + > +UCLASS_DRIVER(i2c) = { > + .id = UCLASS_I2C, > + .name = "i2c", > + .per_device_auto_alloc_size = sizeof(struct dm_i2c_bus), > + .post_bind = i2c_post_bind, > + .post_probe = i2c_post_probe, > +}; > + > +UCLASS_DRIVER(i2c_generic) = { > + .id = UCLASS_I2C_GENERIC, > + .name = "i2c_generic", > +}; > + > +U_BOOT_DRIVER(i2c_generic_drv) = { > + .name = "i2c_generic_drv", > + .id = UCLASS_I2C_GENERIC, > +}; > diff --git a/include/config_fallbacks.h b/include/config_fallbacks.h > index 7d8daa2..91a0a43 100644 > --- a/include/config_fallbacks.h > +++ b/include/config_fallbacks.h > @@ -87,4 +87,10 @@ > #undef CONFIG_IMAGE_FORMAT_LEGACY > #endif > > +#ifdef CONFIG_DM_I2C > +# ifdef CONFIG_SYS_I2C > +# error "Cannot define CONFIG_SYS_I2C when CONFIG_DM_I2C is used" > +# endif > +#endif > + > #endif /* __CONFIG_FALLBACKS_H */ > diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h > index a8944c9..43514bc 100644 > --- a/include/dm/uclass-id.h > +++ b/include/dm/uclass-id.h > @@ -28,6 +28,8 @@ enum uclass_id { > UCLASS_SPI_GENERIC, /* Generic SPI flash target */ > UCLASS_SPI_FLASH, /* SPI flash */ > UCLASS_CROS_EC, /* Chrome OS EC */ > + UCLASS_I2C, /* I2C bus */ > + UCLASS_I2C_GENERIC, /* Generic I2C device */ > > UCLASS_COUNT, > UCLASS_INVALID = -1, > diff --git a/include/i2c.h b/include/i2c.h > index 1b4078e..dd8fd2e 100644 > --- a/include/i2c.h > +++ b/include/i2c.h > @@ -18,6 +18,351 @@ > #define _I2C_H_ > > /* > + * For now there are essentially two parts to this file - driver model > + * here at the top, and the older code below (with CONFIG_SYS_I2C being > + * most recent). The plan is to migrate everything to driver model. > + * The driver model structures and API are separate as they are different > + * enough as to be incompatible for compilation purposes. > + */ > + > +#ifdef CONFIG_DM_I2C > + > +enum dm_i2c_chip_flags { > + DM_I2C_CHIP_10BIT = 1 << 0, /* Use 10-bit addressing */ > + DM_I2C_CHIP_RE_ADDRESS = 1 << 1, /* Send address for every byte */ > +}; > + > +/** > + * struct dm_i2c_chip - information about an i2c chip > + * > + * An I2C chip is a device on the I2C bus. It sits at a particular address > + * and normally supports 7-bit or 10-bit addressing. > + * > + * To obtain this structure, use dev_get_parentdata(dev) where dev is the > + * chip to examine. > + * > + * @chip_addr: Chip address on bus > + * @offset_len: Length of offset in bytes. A single byte offset can > + * represent up to 256 bytes. A value larger than 1 may be > + * needed for larger devices. > + * @flags: Flags for this chip (dm_i2c_chip_flags) > + * @emul: Emulator for this chip address (only used for emulation) > + */ > +struct dm_i2c_chip { > + uint chip_addr; > + uint offset_len; > + uint flags; > +#ifdef CONFIG_SANDBOX > + struct udevice *emul; > +#endif > +}; > + > +/** > + * struct dm_i2c_bus- information about an i2c bus > + * > + * An I2C bus contains 0 or more chips on it, each at its own address. The > + * bus can operate at different speeds (measured in Hz, typically 100KHz > + * or 400KHz). > + * > + * To obtain this structure, use bus->uclass_priv where bus is the I2C > + * bus udevice. > + * > + * @speed_hz: Bus speed in hertz (typically 100000) > + */ > +struct dm_i2c_bus { > + int speed_hz; > +}; > + > +/** > + * i2c_read() - read bytes from an I2C chip > + * > + * To obtain an I2C device (called a 'chip') given the I2C bus address you > + * can use i2c_get_chip(). To obtain a bus by bus number use > + * uclass_get_device_by_seq(UCLASS_I2C, <bus number>). > + * > + * To set the address length of a devce use i2c_set_addr_len(). It > + * defaults to 1. > + * > + * @dev: Chip to read from > + * @offset: Offset within chip to start reading > + * @buffer: Place to put data > + * @len: Number of bytes to read > + * > + * @return 0 on success, -ve on failure > + */ > +int i2c_read(struct udevice *dev, uint offset, uint8_t *buffer, > + int len); > + > +/** > + * i2c_write() - write bytes to an I2C chip > + * > + * See notes for i2c_read() above. > + * > + * @dev: Chip to write to > + * @offset: Offset within chip to start writing > + * @buffer: Buffer containing data to write > + * @len: Number of bytes to write > + * > + * @return 0 on success, -ve on failure > + */ > +int i2c_write(struct udevice *dev, uint offset, const uint8_t *buffer, > + int len); > + > +/** > + * i2c_probe() - probe a particular chip address > + * > + * This can be useful to check for the existence of a chip on the bus. > + * It is typically implemented by writing the chip address to the bus > + * and checking that the chip replies with an ACK. > + * > + * @bus: Bus to probe > + * @chip_addr: 7-bit address to probe (10-bit and others are not > supported) > + * @devp: Returns the device found, or NULL if none > + * @return 0 if a chip was found at that address, -ve if not > + */ > +int i2c_probe(struct udevice *bus, uint chip_addr, struct udevice **devp); > + > +/** > + * i2c_set_bus_speed() - set the speed of a bus > + * > + * @bus: Bus to adjust > + * @speed: Requested speed in Hz > + * @return 0 if OK, -EINVAL for invalid values > + */ > +int i2c_set_bus_speed(struct udevice *bus, unsigned int speed); > + > +/** > + * i2c_get_bus_speed() - get the speed of a bus > + * > + * @bus: Bus to check > + * @return speed of selected I2C bus in Hz, -ve on error > + */ > +int i2c_get_bus_speed(struct udevice *bus); > + > +/** > + * i2c_set_chip_flags() - set flags for a chip > + * > + * Typically addresses are 7 bits, but for 10-bit addresses you should set > + * flags to DM_I2C_CHIP_10BIT. All accesses will then use 10-bit > addressing. > + * > + * @dev: Chip to adjust > + * @flags: New flags > + * @return 0 if OK, -EINVAL if value is unsupported, other -ve value on > error > + */ > +int i2c_set_chip_flags(struct udevice *dev, uint flags); > + > +/** > + * i2c_get_chip_flags() - get flags for a chip > + * > + * @dev: Chip to check > + * @flagsp: Place to put flags > + * @return 0 if OK, other -ve value on error > + */ > +int i2c_get_chip_flags(struct udevice *dev, uint *flagsp); > + > +/** > + * i2c_set_offset_len() - set the offset length for a chip > + * > + * The offset used to access a chip may be up to 4 bytes long. Typically > it > + * is only 1 byte, which is enough for chips with 256 bytes of memory or > + * registers. The default value is 1, but you can call this function to > + * change it. > + * > + * @offset_len: New offset length value (typically 1 or 2) > + */ > + > +int i2c_set_chip_offset_len(struct udevice *dev, uint offset_len); > +/** > + * i2c_deblock() - recover a bus that is in an unknown state > + * > + * See the deblock() method in 'struct dm_i2c_ops' for full information > + * > + * @bus: Bus to recover > + * @return 0 if OK, -ve on error > + */ > +int i2c_deblock(struct udevice *bus); > + > +/* > + * Not all of these flags are implemented in the U-Boot API > + */ > +enum dm_i2c_msg_flags { > + I2C_M_TEN = 0x0010, /* ten-bit chip address */ > + I2C_M_RD = 0x0001, /* read data, from slave to > master */ > + I2C_M_STOP = 0x8000, /* send stop after this message > */ > + I2C_M_NOSTART = 0x4000, /* no start before this message > */ > + I2C_M_REV_DIR_ADDR = 0x2000, /* invert polarity of R/W bit */ > + I2C_M_IGNORE_NAK = 0x1000, /* continue after NAK */ > + I2C_M_NO_RD_ACK = 0x0800, /* skip the Ack bit on reads */ > + I2C_M_RECV_LEN = 0x0400, /* length is first received byte > */ > +}; > + > +/** > + * struct i2c_msg - an I2C message > + * > + * @addr: Slave address > + * @flags: Flags (see enum dm_i2c_msg_flags) > + * @len: Length of buffer in bytes > + * @buf: Buffer to send/receive > + */ > +struct i2c_msg { > + uint addr; > + uint flags; > + uint len; > + u8 *buf; > +}; > + > +/** > + * struct i2c_msg_list - a list of I2C messages > + * > + * This is called i2c_rdwr_ioctl_data in Linux but the name does not seem > + * appropriate in U-Boot. > + * > + * @msg: Pointer to i2c_msg array > + * @nmsgs: Number of elements in the array > + */ > +struct i2c_msg_list { > + struct i2c_msg *msgs; > + uint nmsgs; > +}; > + > +/** > + * struct dm_i2c_ops - driver operations for I2C uclass > + * > + * Drivers should support these operations unless otherwise noted. These > + * operations are intended to be used by uclass code, not directly from > + * other code. > + */ > +struct dm_i2c_ops { > + /** > + * xfer() - transfer a list of I2C messages > + * > + * @bus: Bus to read from > + * @chip_addr: Chip address to read from > + * @offset: Offset within chip to start reading > + * @olen: Length of chip offset in bytes > + * @buffer: Place to put data > + * @len: Number of bytes to read > + * @return 0 if OK, -EREMOTEIO if the slave did not ACK a byte, > + * other -ve value on some other error > + */ > + int (*xfer)(struct udevice *bus, struct i2c_msg *msg, int nmsgs); > + > + /** > + * set_bus_speed() - set the speed of a bus (optional) > + * > + * The bus speed value will be updated by the uclass if this > function > + * does not return an error. > + * > + * @bus: Bus to adjust > + * @speed: Requested speed in Hz > + * @return 0 if OK, -INVAL for invalid values > + */ > + int (*set_bus_speed)(struct udevice *bus, unsigned int speed); > + > + /** > + * get_bus_speed() - get the speed of a bus (optional) > + * > + * Normally this can be provided by the uclass, but if you want > your > + * driver to check the bus speed by looking at the hardware, you > can > + * implement that here. > + * > + * @bus: Bus to check > + * @return speed of selected I2C bus in Hz, -ve on error > + */ > + int (*get_bus_speed)(struct udevice *bus); > + > + /** > + * set_flags() - set the flags for a chip (optional) > + * > + * This is generally implemented by the uclass, but drivers can > + * check the value to ensure that unsupported options are not used. > + * If provided, this method will always be called when the flags > + * change. > + * > + * @dev: Chip to adjust > + * @flags: New flags value > + * @return 0 if OK, -EINVAL if value is unsupported > + */ > + int (*set_flags)(struct udevice *dev, uint flags); > + > + /** > + * set_offset_len() - set the offset length of a chip (optional) > + * > + * This is generally implemented by the uclass, but drivers can > + * check the value to ensure that unsupported options are not used. > + * If provided, this method will always be called when the offset > + * length changes from the default of 1. > + * > + * @dev: Chip to adjust > + * @addr_len: New offset length value (typically 1 or 2) > + * @return 0 if OK, -INVAL if value is unsupported > + */ > + int (*set_offset_len)(struct udevice *dev, uint offset_len); > + > + /** > + * deblock() - recover a bus that is in an unknown state > + * > + * I2C is a synchronous protocol and resets of the processor in the > + * middle of an access can block the I2C Bus until a powerdown of > + * the full unit is done. This is because slaves can be stuck > + * waiting for addition bus transitions for a transaction that will > + * never complete. Resetting the I2C master does not help. The only > + * way is to force the bus through a series of transitions to make > + * sure that all slaves are done with the transaction. This method > + * performs this 'deblocking' if support by the driver. > + * > + * This method is optional. > + */ > + int (*deblock)(struct udevice *bus); > +}; > + > +#define i2c_get_ops(dev) ((struct dm_i2c_ops *)(dev)->driver->ops) > + > +/** > + * i2c_get_chip() - get a device to use to access a chip on a bus > + * > + * This returns the device for the given chip address. The device can then > + * be used with calls to i2c_read(), i2c_write(), i2c_probe(), etc. > + * > + * @bus: Bus to examine > + * @chip_addr: Chip address for the new device > + * @devp: Returns pointer to new device if found or -ENODEV if not > + * found > + */ > +int i2c_get_chip(struct udevice *bus, uint chip_addr, struct udevice > **devp); > + > +/** > + * i2c_get_chip() - get a device to use to access a chip on a bus number > + * > + * This returns the device for the given chip address on a particular bus > + * number. > + * > + * @busnum: Bus number to examine > + * @chip_addr: Chip address for the new device > + * @devp: Returns pointer to new device if found or -ENODEV if not > + * found > + */ > +int i2c_get_chip_for_busnum(int busnum, int chip_addr, struct udevice > **devp); > + > +/** > + * i2c_chip_ofdata_to_platdata() - Decode standard I2C platform data > + * > + * This decodes the chip address from a device tree node and puts it into > + * its dm_i2c_chip structure. This should be called in your driver's > + * ofdata_to_platdata() method. > + * > + * @blob: Device tree blob > + * @node: Node offset to read from > + * @spi: Place to put the decoded information > + */ > +int i2c_chip_ofdata_to_platdata(const void *blob, int node, > + struct dm_i2c_chip *chip); > + > +#endif > + > +#ifndef CONFIG_DM_I2C > + > +/* > * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING > * > * The implementation MUST NOT use static or global variables if the > @@ -451,4 +796,7 @@ int i2c_get_bus_num_fdt(int node); > * @return 0 if port was reset, -1 if not found > */ > int i2c_reset_port_fdt(const void *blob, int node); > + > +#endif /* !CONFIG_DM_I2C */ > + > #endif /* _I2C_H_ */ > -- > 2.1.0.rc2.206.gedb03e5 > >
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