From 2187f03a9576c4fb8342deed912b5ba6fcf98cba Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Mon, 5 Jan 2015 15:35:39 +0100 Subject: i2c: add quirk structure to describe adapter flaws The number of I2C adapters which are not fully I2C compatible is rising, sadly. Drivers usually do handle the flaws, still the user receives only some errno for a transfer which normally can be expected to work. This patch introduces a formal description of flaws. One advantage is that the core can check before the actual transfer if the messages could be transferred at all. This is done in the next patch. Another advantage is that we can pass this information to the user so the restrictions are exactly known and further actions can be based on that. This will be done later after some stabilization period for this description. Signed-off-by: Wolfram Sang Tested-by: Ray Jui Tested-by: Ivan T. Ivanov Tested-by: Neelesh Gupta Tested-By: Ludovic Desroches --- include/linux/i2c.h | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) (limited to 'include/linux/i2c.h') diff --git a/include/linux/i2c.h b/include/linux/i2c.h index f17da50402a4..243d1a1d78b2 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -449,6 +449,48 @@ int i2c_recover_bus(struct i2c_adapter *adap); int i2c_generic_gpio_recovery(struct i2c_adapter *adap); int i2c_generic_scl_recovery(struct i2c_adapter *adap); +/** + * struct i2c_adapter_quirks - describe flaws of an i2c adapter + * @flags: see I2C_AQ_* for possible flags and read below + * @max_num_msgs: maximum number of messages per transfer + * @max_write_len: maximum length of a write message + * @max_read_len: maximum length of a read message + * @max_comb_1st_msg_len: maximum length of the first msg in a combined message + * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message + * + * Note about combined messages: Some I2C controllers can only send one message + * per transfer, plus something called combined message or write-then-read. + * This is (usually) a small write message followed by a read message and + * barely enough to access register based devices like EEPROMs. There is a flag + * to support this mode. It implies max_num_msg = 2 and does the length checks + * with max_comb_*_len because combined message mode usually has its own + * limitations. Because of HW implementations, some controllers can actually do + * write-then-anything or other variants. To support that, write-then-read has + * been broken out into smaller bits like write-first and read-second which can + * be combined as needed. + */ + +struct i2c_adapter_quirks { + u64 flags; + int max_num_msgs; + u16 max_write_len; + u16 max_read_len; + u16 max_comb_1st_msg_len; + u16 max_comb_2nd_msg_len; +}; + +/* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */ +#define I2C_AQ_COMB BIT(0) +/* first combined message must be write */ +#define I2C_AQ_COMB_WRITE_FIRST BIT(1) +/* second combined message must be read */ +#define I2C_AQ_COMB_READ_SECOND BIT(2) +/* both combined messages must have the same target address */ +#define I2C_AQ_COMB_SAME_ADDR BIT(3) +/* convenience macro for typical write-then read case */ +#define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \ + I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR) + /* * i2c_adapter is the structure used to identify a physical i2c bus along * with the access algorithms necessary to access it. @@ -474,6 +516,7 @@ struct i2c_adapter { struct list_head userspace_clients; struct i2c_bus_recovery_info *bus_recovery_info; + const struct i2c_adapter_quirks *quirks; }; #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) -- cgit v1.3-14-g43fede From ce793486e23e0162a732c605189c8028e0910e86 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 16 Mar 2015 23:49:03 +0100 Subject: driver core / ACPI: Represent ACPI companions using fwnode_handle Now that we have struct fwnode_handle, we can use that to point to ACPI companions from struct device objects instead of pointing to struct acpi_device directly. There are two benefits from that. First, the somewhat ugly and hackish struct acpi_dev_node can be dropped and, second, the same struct fwnode_handle pointer can be used in the future to point to other (non-ACPI) firmware device node types. Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Acked-by: Grant Likely --- drivers/acpi/acpi_platform.c | 2 +- drivers/acpi/dock.c | 2 +- drivers/base/platform.c | 2 +- drivers/gpio/gpiolib.h | 2 ++ drivers/i2c/i2c-core.c | 4 ++-- include/acpi/acpi_bus.h | 3 ++- include/linux/acpi.h | 5 +++-- include/linux/device.h | 13 +++---------- include/linux/fwnode.h | 25 +++++++++++++++++++++++++ include/linux/i2c.h | 4 ++-- include/linux/platform_device.h | 2 +- include/linux/property.h | 11 +---------- 12 files changed, 44 insertions(+), 31 deletions(-) create mode 100644 include/linux/fwnode.h (limited to 'include/linux/i2c.h') diff --git a/drivers/acpi/acpi_platform.c b/drivers/acpi/acpi_platform.c index 1284138e42ab..4bf75597f732 100644 --- a/drivers/acpi/acpi_platform.c +++ b/drivers/acpi/acpi_platform.c @@ -102,7 +102,7 @@ struct platform_device *acpi_create_platform_device(struct acpi_device *adev) pdevinfo.id = -1; pdevinfo.res = resources; pdevinfo.num_res = count; - pdevinfo.acpi_node.companion = adev; + pdevinfo.fwnode = acpi_fwnode_handle(adev); pdevinfo.dma_mask = DMA_BIT_MASK(32); pdev = platform_device_register_full(&pdevinfo); if (IS_ERR(pdev)) diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c index d9339b442a4e..a688aa243f6c 100644 --- a/drivers/acpi/dock.c +++ b/drivers/acpi/dock.c @@ -615,7 +615,7 @@ void acpi_dock_add(struct acpi_device *adev) memset(&pdevinfo, 0, sizeof(pdevinfo)); pdevinfo.name = "dock"; pdevinfo.id = dock_station_count; - pdevinfo.acpi_node.companion = adev; + pdevinfo.fwnode = acpi_fwnode_handle(adev); pdevinfo.data = &ds; pdevinfo.size_data = sizeof(ds); dd = platform_device_register_full(&pdevinfo); diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 9421fed40905..17f0204fabef 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -454,7 +454,7 @@ struct platform_device *platform_device_register_full( goto err_alloc; pdev->dev.parent = pdevinfo->parent; - ACPI_COMPANION_SET(&pdev->dev, pdevinfo->acpi_node.companion); + pdev->dev.fwnode = pdevinfo->fwnode; if (pdevinfo->dma_mask) { /* diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h index 550a5eafbd38..ab892be26dc2 100644 --- a/drivers/gpio/gpiolib.h +++ b/drivers/gpio/gpiolib.h @@ -17,6 +17,8 @@ enum of_gpio_flags; +struct acpi_device; + /** * struct acpi_gpio_info - ACPI GPIO specific information * @gpioint: if %true this GPIO is of type GpioInt otherwise type is GpioIo diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index edf274cabe81..c87c31387e2d 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -133,7 +133,7 @@ static acpi_status acpi_i2c_add_device(acpi_handle handle, u32 level, return AE_OK; memset(&info, 0, sizeof(info)); - info.acpi_node.companion = adev; + info.fwnode = acpi_fwnode_handle(adev); info.irq = -1; INIT_LIST_HEAD(&resource_list); @@ -971,7 +971,7 @@ i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) client->dev.bus = &i2c_bus_type; client->dev.type = &i2c_client_type; client->dev.of_node = info->of_node; - ACPI_COMPANION_SET(&client->dev, info->acpi_node.companion); + client->dev.fwnode = info->fwnode; i2c_dev_set_name(adap, client); status = device_register(&client->dev); diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h index 61e32ec1fc4d..dae2a16fe93f 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -386,7 +386,8 @@ static inline bool is_acpi_node(struct fwnode_handle *fwnode) static inline struct acpi_device *acpi_node(struct fwnode_handle *fwnode) { - return fwnode ? container_of(fwnode, struct acpi_device, fwnode) : NULL; + return is_acpi_node(fwnode) ? + container_of(fwnode, struct acpi_device, fwnode) : NULL; } static inline struct fwnode_handle *acpi_fwnode_handle(struct acpi_device *adev) diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 24c7aa8b1d20..402ddbdc2da1 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -53,8 +53,9 @@ static inline acpi_handle acpi_device_handle(struct acpi_device *adev) return adev ? adev->handle : NULL; } -#define ACPI_COMPANION(dev) ((dev)->acpi_node.companion) -#define ACPI_COMPANION_SET(dev, adev) ACPI_COMPANION(dev) = (adev) +#define ACPI_COMPANION(dev) acpi_node((dev)->fwnode) +#define ACPI_COMPANION_SET(dev, adev) (dev)->fwnode = (adev) ? \ + acpi_fwnode_handle(adev) : NULL #define ACPI_HANDLE(dev) acpi_device_handle(ACPI_COMPANION(dev)) static inline void acpi_preset_companion(struct device *dev, diff --git a/include/linux/device.h b/include/linux/device.h index 0eb8ee2dc6d1..badef20b876a 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -38,6 +38,7 @@ struct class; struct subsys_private; struct bus_type; struct device_node; +struct fwnode_handle; struct iommu_ops; struct iommu_group; @@ -650,14 +651,6 @@ struct device_dma_parameters { unsigned long segment_boundary_mask; }; -struct acpi_device; - -struct acpi_dev_node { -#ifdef CONFIG_ACPI - struct acpi_device *companion; -#endif -}; - /** * struct device - The basic device structure * @parent: The device's "parent" device, the device to which it is attached. @@ -703,7 +696,7 @@ struct acpi_dev_node { * @cma_area: Contiguous memory area for dma allocations * @archdata: For arch-specific additions. * @of_node: Associated device tree node. - * @acpi_node: Associated ACPI device node. + * @fwnode: Associated device node supplied by platform firmware. * @devt: For creating the sysfs "dev". * @id: device instance * @devres_lock: Spinlock to protect the resource of the device. @@ -779,7 +772,7 @@ struct device { struct dev_archdata archdata; struct device_node *of_node; /* associated device tree node */ - struct acpi_dev_node acpi_node; /* associated ACPI device node */ + struct fwnode_handle *fwnode; /* firmware device node */ dev_t devt; /* dev_t, creates the sysfs "dev" */ u32 id; /* device instance */ diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h new file mode 100644 index 000000000000..17bb5f039509 --- /dev/null +++ b/include/linux/fwnode.h @@ -0,0 +1,25 @@ +/* + * fwnode.h - Firmware device node object handle type definition. + * + * Copyright (C) 2015, Intel Corporation + * Author: Rafael J. Wysocki + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef _LINUX_FWNODE_H_ +#define _LINUX_FWNODE_H_ + +enum fwnode_type { + FWNODE_INVALID = 0, + FWNODE_OF, + FWNODE_ACPI, +}; + +struct fwnode_handle { + enum fwnode_type type; +}; + +#endif diff --git a/include/linux/i2c.h b/include/linux/i2c.h index f17da50402a4..6d89575361a8 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -278,7 +278,7 @@ static inline int i2c_slave_event(struct i2c_client *client, * @platform_data: stored in i2c_client.dev.platform_data * @archdata: copied into i2c_client.dev.archdata * @of_node: pointer to OpenFirmware device node - * @acpi_node: ACPI device node + * @fwnode: device node supplied by the platform firmware * @irq: stored in i2c_client.irq * * I2C doesn't actually support hardware probing, although controllers and @@ -299,7 +299,7 @@ struct i2c_board_info { void *platform_data; struct dev_archdata *archdata; struct device_node *of_node; - struct acpi_dev_node acpi_node; + struct fwnode_handle *fwnode; int irq; }; diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h index ae4882ca4a64..58f1e75ba105 100644 --- a/include/linux/platform_device.h +++ b/include/linux/platform_device.h @@ -59,7 +59,7 @@ extern int platform_add_devices(struct platform_device **, int); struct platform_device_info { struct device *parent; - struct acpi_dev_node acpi_node; + struct fwnode_handle *fwnode; const char *name; int id; diff --git a/include/linux/property.h b/include/linux/property.h index a6a3d98bd7e9..31dfd3db35d6 100644 --- a/include/linux/property.h +++ b/include/linux/property.h @@ -13,6 +13,7 @@ #ifndef _LINUX_PROPERTY_H_ #define _LINUX_PROPERTY_H_ +#include #include struct device; @@ -40,16 +41,6 @@ int device_property_read_string_array(struct device *dev, const char *propname, int device_property_read_string(struct device *dev, const char *propname, const char **val); -enum fwnode_type { - FWNODE_INVALID = 0, - FWNODE_OF, - FWNODE_ACPI, -}; - -struct fwnode_handle { - enum fwnode_type type; -}; - bool fwnode_property_present(struct fwnode_handle *fwnode, const char *propname); int fwnode_property_read_u8_array(struct fwnode_handle *fwnode, const char *propname, u8 *val, -- cgit v1.3-14-g43fede From 5b77d162a3d7359a8a8d83776720da065bf4e77b Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Mon, 23 Mar 2015 09:26:36 +0100 Subject: i2c: slave: rework the slave API MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit After more discussion, brave users, and additional datasheet evaluation, some API updates for the new I2C slave framework became imminent. The slave events now get some easier to understand naming. Also, the event handling has been simplified to only need a single call to the slave callback when an action by the backend is required. Reported-by: Uwe Kleine-König Signed-off-by: Wolfram Sang Acked-by: Geert Uytterhoeven Acked-by: Uwe Kleine-König Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-rcar.c | 10 ++++------ drivers/i2c/i2c-slave-eeprom.c | 12 ++++++------ include/linux/i2c.h | 8 ++++---- 3 files changed, 14 insertions(+), 16 deletions(-) (limited to 'include/linux/i2c.h') diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index 71a6e07eb7ab..5a84bea5b845 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -382,11 +382,11 @@ static bool rcar_i2c_slave_irq(struct rcar_i2c_priv *priv) if (ssr_filtered & SAR) { /* read or write request */ if (ssr_raw & STM) { - i2c_slave_event(priv->slave, I2C_SLAVE_REQ_READ_START, &value); + i2c_slave_event(priv->slave, I2C_SLAVE_READ_REQUESTED, &value); rcar_i2c_write(priv, ICRXTX, value); rcar_i2c_write(priv, ICSIER, SDE | SSR | SAR); } else { - i2c_slave_event(priv->slave, I2C_SLAVE_REQ_WRITE_START, &value); + i2c_slave_event(priv->slave, I2C_SLAVE_WRITE_REQUESTED, &value); rcar_i2c_read(priv, ICRXTX); /* dummy read */ rcar_i2c_write(priv, ICSIER, SDR | SSR | SAR); } @@ -406,17 +406,15 @@ static bool rcar_i2c_slave_irq(struct rcar_i2c_priv *priv) int ret; value = rcar_i2c_read(priv, ICRXTX); - ret = i2c_slave_event(priv->slave, I2C_SLAVE_REQ_WRITE_END, &value); + ret = i2c_slave_event(priv->slave, I2C_SLAVE_WRITE_RECEIVED, &value); /* Send NACK in case of error */ rcar_i2c_write(priv, ICSCR, SIE | SDBS | (ret < 0 ? FNA : 0)); - i2c_slave_event(priv->slave, I2C_SLAVE_REQ_WRITE_START, &value); rcar_i2c_write(priv, ICSSR, ~SDR & 0xff); } /* master wants to read from us */ if (ssr_filtered & SDE) { - i2c_slave_event(priv->slave, I2C_SLAVE_REQ_READ_END, &value); - i2c_slave_event(priv->slave, I2C_SLAVE_REQ_READ_START, &value); + i2c_slave_event(priv->slave, I2C_SLAVE_READ_PROCESSED, &value); rcar_i2c_write(priv, ICRXTX, value); rcar_i2c_write(priv, ICSSR, ~SDE & 0xff); } diff --git a/drivers/i2c/i2c-slave-eeprom.c b/drivers/i2c/i2c-slave-eeprom.c index cf9b09db092f..3fb45d894d80 100644 --- a/drivers/i2c/i2c-slave-eeprom.c +++ b/drivers/i2c/i2c-slave-eeprom.c @@ -36,7 +36,7 @@ static int i2c_slave_eeprom_slave_cb(struct i2c_client *client, struct eeprom_data *eeprom = i2c_get_clientdata(client); switch (event) { - case I2C_SLAVE_REQ_WRITE_END: + case I2C_SLAVE_WRITE_RECEIVED: if (eeprom->first_write) { eeprom->buffer_idx = *val; eeprom->first_write = false; @@ -47,17 +47,17 @@ static int i2c_slave_eeprom_slave_cb(struct i2c_client *client, } break; - case I2C_SLAVE_REQ_READ_START: + case I2C_SLAVE_READ_PROCESSED: + eeprom->buffer_idx++; + /* fallthrough */ + case I2C_SLAVE_READ_REQUESTED: spin_lock(&eeprom->buffer_lock); *val = eeprom->buffer[eeprom->buffer_idx]; spin_unlock(&eeprom->buffer_lock); break; - case I2C_SLAVE_REQ_READ_END: - eeprom->buffer_idx++; - break; - case I2C_SLAVE_STOP: + case I2C_SLAVE_WRITE_REQUESTED: eeprom->first_write = true; break; diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 243d1a1d78b2..c5e4bb2c5759 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -253,10 +253,10 @@ static inline void i2c_set_clientdata(struct i2c_client *dev, void *data) #if IS_ENABLED(CONFIG_I2C_SLAVE) enum i2c_slave_event { - I2C_SLAVE_REQ_READ_START, - I2C_SLAVE_REQ_READ_END, - I2C_SLAVE_REQ_WRITE_START, - I2C_SLAVE_REQ_WRITE_END, + I2C_SLAVE_READ_REQUESTED, + I2C_SLAVE_WRITE_REQUESTED, + I2C_SLAVE_READ_PROCESSED, + I2C_SLAVE_WRITE_RECEIVED, I2C_SLAVE_STOP, }; -- cgit v1.3-14-g43fede From 2b2190a375d796a5ad9ec557cb51269f36b264d4 Mon Sep 17 00:00:00 2001 From: Grygorii Strashko Date: Mon, 6 Apr 2015 15:38:39 +0300 Subject: i2c: change input parameter to i2c_adapter for prepare/unprepare_recovery MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch changes type of input parameter for prepare/unprepare_recovery() callbacks from struct i2c_bus_recovery_info * to struct i2c_adapter *. This allows to simplify implementation of these callbacks and avoid type conversations from i2c_bus_recovery_info to i2c_adapter. The i2c_bus_recovery_info can be simply retrieved from struct i2c_adapter which contains pointer on it. There are no users currently, so this is safe to do. Acked-by: Uwe Kleine-König Acked-by: Alexander Sverdlin Signed-off-by: Grygorii Strashko Signed-off-by: Wolfram Sang --- drivers/i2c/i2c-core.c | 4 ++-- include/linux/i2c.h | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) (limited to 'include/linux/i2c.h') diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index fe80f85896e2..617a19acf76a 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -561,7 +561,7 @@ static int i2c_generic_recovery(struct i2c_adapter *adap) int i = 0, val = 1, ret = 0; if (bri->prepare_recovery) - bri->prepare_recovery(bri); + bri->prepare_recovery(adap); /* * By this time SCL is high, as we need to give 9 falling-rising edges @@ -586,7 +586,7 @@ static int i2c_generic_recovery(struct i2c_adapter *adap) } if (bri->unprepare_recovery) - bri->unprepare_recovery(bri); + bri->unprepare_recovery(adap); return ret; } diff --git a/include/linux/i2c.h b/include/linux/i2c.h index c5e4bb2c5759..898033f41d76 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -435,8 +435,8 @@ struct i2c_bus_recovery_info { void (*set_scl)(struct i2c_adapter *, int val); int (*get_sda)(struct i2c_adapter *); - void (*prepare_recovery)(struct i2c_bus_recovery_info *bri); - void (*unprepare_recovery)(struct i2c_bus_recovery_info *bri); + void (*prepare_recovery)(struct i2c_adapter *); + void (*unprepare_recovery)(struct i2c_adapter *); /* gpio recovery */ int scl_gpio; -- cgit v1.3-14-g43fede