I2C slave support (c) 2014 by Wolfram Sang <wsa@sang-engineering.com>
*/
+#include <dt-bindings/i2c/i2c.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/rwsem.h>
#include <linux/pm_runtime.h>
#include <linux/pm_domain.h>
+#include <linux/pm_wakeirq.h>
#include <linux/acpi.h>
#include <linux/jump_label.h>
#include <asm/uaccess.h>
#define CREATE_TRACE_POINTS
#include <trace/events/i2c.h>
+#define I2C_ADDR_OFFSET_TEN_BIT 0xa000
+#define I2C_ADDR_OFFSET_SLAVE 0x1000
+
/* core_lock protects i2c_adapter_idr, and guarantees
that device detection, deletion of detected devices, and attach_adapter
calls are serialized */
if (bri->prepare_recovery)
bri->prepare_recovery(adap);
+ bri->set_scl(adap, val);
+ ndelay(RECOVERY_NDELAY);
+
/*
* By this time SCL is high, as we need to give 9 falling-rising edges
*/
int i2c_generic_scl_recovery(struct i2c_adapter *adap)
{
- adap->bus_recovery_info->set_scl(adap, 1);
return i2c_generic_recovery(adap);
}
EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery);
if (!client->irq) {
int irq = -ENOENT;
- if (dev->of_node)
- irq = of_irq_get(dev->of_node, 0);
- else if (ACPI_COMPANION(dev))
+ if (dev->of_node) {
+ irq = of_irq_get_byname(dev->of_node, "irq");
+ if (irq == -EINVAL || irq == -ENODATA)
+ irq = of_irq_get(dev->of_node, 0);
+ } else if (ACPI_COMPANION(dev)) {
irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 0);
-
+ }
if (irq == -EPROBE_DEFER)
return irq;
if (irq < 0)
if (!driver->probe || !driver->id_table)
return -ENODEV;
- if (!device_can_wakeup(&client->dev))
- device_init_wakeup(&client->dev,
- client->flags & I2C_CLIENT_WAKE);
+ if (client->flags & I2C_CLIENT_WAKE) {
+ int wakeirq = -ENOENT;
+
+ if (dev->of_node) {
+ wakeirq = of_irq_get_byname(dev->of_node, "wakeup");
+ if (wakeirq == -EPROBE_DEFER)
+ return wakeirq;
+ }
+
+ device_init_wakeup(&client->dev, true);
+
+ if (wakeirq > 0 && wakeirq != client->irq)
+ status = dev_pm_set_dedicated_wake_irq(dev, wakeirq);
+ else if (client->irq > 0)
+ status = dev_pm_set_wake_irq(dev, wakeirq);
+ else
+ status = 0;
+
+ if (status)
+ dev_warn(&client->dev, "failed to set up wakeup irq");
+ }
+
dev_dbg(dev, "probe\n");
status = of_clk_set_defaults(dev->of_node, false);
if (status < 0)
- return status;
+ goto err_clear_wakeup_irq;
status = dev_pm_domain_attach(&client->dev, true);
- if (status != -EPROBE_DEFER) {
- status = driver->probe(client, i2c_match_id(driver->id_table,
- client));
- if (status)
- dev_pm_domain_detach(&client->dev, true);
- }
+ if (status == -EPROBE_DEFER)
+ goto err_clear_wakeup_irq;
+ status = driver->probe(client, i2c_match_id(driver->id_table, client));
+ if (status)
+ goto err_detach_pm_domain;
+
+ return 0;
+
+err_detach_pm_domain:
+ dev_pm_domain_detach(&client->dev, true);
+err_clear_wakeup_irq:
+ dev_pm_clear_wake_irq(&client->dev);
+ device_init_wakeup(&client->dev, false);
return status;
}
}
dev_pm_domain_detach(&client->dev, true);
+
+ dev_pm_clear_wake_irq(&client->dev);
+ device_init_wakeup(&client->dev, false);
+
return status;
}
EXPORT_SYMBOL(i2c_verify_client);
+/* Return a unique address which takes the flags of the client into account */
+static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client)
+{
+ unsigned short addr = client->addr;
+
+ /* For some client flags, add an arbitrary offset to avoid collisions */
+ if (client->flags & I2C_CLIENT_TEN)
+ addr |= I2C_ADDR_OFFSET_TEN_BIT;
+
+ if (client->flags & I2C_CLIENT_SLAVE)
+ addr |= I2C_ADDR_OFFSET_SLAVE;
+
+ return addr;
+}
+
/* This is a permissive address validity check, I2C address map constraints
* are purposely not enforced, except for the general call address. */
-static int i2c_check_client_addr_validity(const struct i2c_client *client)
+static int i2c_check_addr_validity(unsigned addr, unsigned short flags)
{
- if (client->flags & I2C_CLIENT_TEN) {
+ if (flags & I2C_CLIENT_TEN) {
/* 10-bit address, all values are valid */
- if (client->addr > 0x3ff)
+ if (addr > 0x3ff)
return -EINVAL;
} else {
/* 7-bit address, reject the general call address */
- if (client->addr == 0x00 || client->addr > 0x7f)
+ if (addr == 0x00 || addr > 0x7f)
return -EINVAL;
}
return 0;
* device uses a reserved address, then it shouldn't be probed. 7-bit
* addressing is assumed, 10-bit address devices are rare and should be
* explicitly enumerated. */
-static int i2c_check_addr_validity(unsigned short addr)
+static int i2c_check_7bit_addr_validity_strict(unsigned short addr)
{
/*
* Reserved addresses per I2C specification:
struct i2c_client *client = i2c_verify_client(dev);
int addr = *(int *)addrp;
- if (client && client->addr == addr)
+ if (client && i2c_encode_flags_to_addr(client) == addr)
return -EBUSY;
return 0;
}
return;
}
- /* For 10-bit clients, add an arbitrary offset to avoid collisions */
dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
- client->addr | ((client->flags & I2C_CLIENT_TEN)
- ? 0xa000 : 0));
+ i2c_encode_flags_to_addr(client));
}
/**
strlcpy(client->name, info->type, sizeof(client->name));
- /* Check for address validity */
- status = i2c_check_client_addr_validity(client);
+ status = i2c_check_addr_validity(client->addr, client->flags);
if (status) {
dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n",
client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr);
}
/* Check for address business */
- status = i2c_check_addr_busy(adap, client->addr);
+ status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client));
if (status)
goto out_err;
return -EINVAL;
}
+ if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) {
+ info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT;
+ info.flags |= I2C_CLIENT_TEN;
+ }
+
+ if (info.addr & I2C_ADDR_OFFSET_SLAVE) {
+ info.addr &= ~I2C_ADDR_OFFSET_SLAVE;
+ info.flags |= I2C_CLIENT_SLAVE;
+ }
+
client = i2c_new_device(adap, &info);
if (!client)
return -EINVAL;
i2c_adapter_depth(adap));
list_for_each_entry_safe(client, next, &adap->userspace_clients,
detected) {
- if (client->addr == addr) {
+ if (i2c_encode_flags_to_addr(client) == addr) {
dev_info(dev, "%s: Deleting device %s at 0x%02hx\n",
"delete_device", client->name, client->addr);
struct i2c_client *result;
struct i2c_board_info info = {};
struct dev_archdata dev_ad = {};
- const __be32 *addr;
+ const __be32 *addr_be;
+ u32 addr;
int len;
dev_dbg(&adap->dev, "of_i2c: register %s\n", node->full_name);
return ERR_PTR(-EINVAL);
}
- addr = of_get_property(node, "reg", &len);
- if (!addr || (len < sizeof(*addr))) {
+ addr_be = of_get_property(node, "reg", &len);
+ if (!addr_be || (len < sizeof(*addr_be))) {
dev_err(&adap->dev, "of_i2c: invalid reg on %s\n",
node->full_name);
return ERR_PTR(-EINVAL);
}
- info.addr = be32_to_cpup(addr);
- if (info.addr > (1 << 10) - 1) {
+ addr = be32_to_cpup(addr_be);
+ if (addr & I2C_TEN_BIT_ADDRESS) {
+ addr &= ~I2C_TEN_BIT_ADDRESS;
+ info.flags |= I2C_CLIENT_TEN;
+ }
+
+ if (addr & I2C_OWN_SLAVE_ADDRESS) {
+ addr &= ~I2C_OWN_SLAVE_ADDRESS;
+ info.flags |= I2C_CLIENT_SLAVE;
+ }
+
+ if (i2c_check_addr_validity(addr, info.flags)) {
dev_err(&adap->dev, "of_i2c: invalid addr=%x on %s\n",
info.addr, node->full_name);
return ERR_PTR(-EINVAL);
}
+ info.addr = addr;
info.of_node = of_node_get(node);
info.archdata = &dev_ad;
struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
{
struct device *dev;
+ struct i2c_client *client;
- dev = bus_find_device(&i2c_bus_type, NULL, node,
- of_dev_node_match);
+ dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match);
if (!dev)
return NULL;
- return i2c_verify_client(dev);
+ client = i2c_verify_client(dev);
+ if (!client)
+ put_device(dev);
+
+ return client;
}
EXPORT_SYMBOL(of_find_i2c_device_by_node);
struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
{
struct device *dev;
+ struct i2c_adapter *adapter;
- dev = bus_find_device(&i2c_bus_type, NULL, node,
- of_dev_node_match);
+ dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match);
if (!dev)
return NULL;
- return i2c_verify_adapter(dev);
+ adapter = i2c_verify_adapter(dev);
+ if (!adapter)
+ put_device(dev);
+
+ return adapter;
}
EXPORT_SYMBOL(of_find_i2c_adapter_by_node);
+
+/* must call i2c_put_adapter() when done with returned i2c_adapter device */
+struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
+{
+ struct i2c_adapter *adapter;
+
+ adapter = of_find_i2c_adapter_by_node(node);
+ if (!adapter)
+ return NULL;
+
+ if (!try_module_get(adapter->owner)) {
+ put_device(&adapter->dev);
+ adapter = NULL;
+ }
+
+ return adapter;
+}
+EXPORT_SYMBOL(of_get_i2c_adapter_by_node);
#else
static void of_i2c_register_devices(struct i2c_adapter *adap) { }
#endif /* CONFIG_OF */
int err;
/* Make sure the address is valid */
- err = i2c_check_addr_validity(addr);
+ err = i2c_check_7bit_addr_validity_strict(addr);
if (err) {
dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",
addr);
return err;
}
- /* Skip if already in use */
+ /* Skip if already in use (7 bit, no need to encode flags) */
if (i2c_check_addr_busy(adapter, addr))
return 0;
for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) {
/* Check address validity */
- if (i2c_check_addr_validity(addr_list[i]) < 0) {
+ if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) {
dev_warn(&adap->dev, "Invalid 7-bit address "
"0x%02x\n", addr_list[i]);
continue;
}
- /* Check address availability */
+ /* Check address availability (7 bit, no need to encode flags) */
if (i2c_check_addr_busy(adap, addr_list[i])) {
dev_dbg(&adap->dev, "Address 0x%02x already in "
"use, not probing\n", addr_list[i]);
mutex_lock(&core_lock);
adapter = idr_find(&i2c_adapter_idr, nr);
- if (adapter && !try_module_get(adapter->owner))
+ if (!adapter)
+ goto exit;
+
+ if (try_module_get(adapter->owner))
+ get_device(&adapter->dev);
+ else
adapter = NULL;
+ exit:
mutex_unlock(&core_lock);
return adapter;
}
void i2c_put_adapter(struct i2c_adapter *adap)
{
- if (adap)
- module_put(adap->owner);
+ if (!adap)
+ return;
+
+ put_device(&adap->dev);
+ module_put(adap->owner);
}
EXPORT_SYMBOL(i2c_put_adapter);
}
EXPORT_SYMBOL(i2c_smbus_xfer);
+/**
+ * i2c_smbus_read_i2c_block_data_or_emulated - read block or emulate
+ * @client: Handle to slave device
+ * @command: Byte interpreted by slave
+ * @length: Size of data block; SMBus allows at most I2C_SMBUS_BLOCK_MAX bytes
+ * @values: Byte array into which data will be read; big enough to hold
+ * the data returned by the slave. SMBus allows at most
+ * I2C_SMBUS_BLOCK_MAX bytes.
+ *
+ * This executes the SMBus "block read" protocol if supported by the adapter.
+ * If block read is not supported, it emulates it using either word or byte
+ * read protocols depending on availability.
+ *
+ * The addresses of the I2C slave device that are accessed with this function
+ * must be mapped to a linear region, so that a block read will have the same
+ * effect as a byte read. Before using this function you must double-check
+ * if the I2C slave does support exchanging a block transfer with a byte
+ * transfer.
+ */
+s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
+ u8 command, u8 length, u8 *values)
+{
+ u8 i = 0;
+ int status;
+
+ if (length > I2C_SMBUS_BLOCK_MAX)
+ length = I2C_SMBUS_BLOCK_MAX;
+
+ if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK))
+ return i2c_smbus_read_i2c_block_data(client, command, length, values);
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA))
+ return -EOPNOTSUPP;
+
+ if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_WORD_DATA)) {
+ while ((i + 2) <= length) {
+ status = i2c_smbus_read_word_data(client, command + i);
+ if (status < 0)
+ return status;
+ values[i] = status & 0xff;
+ values[i + 1] = status >> 8;
+ i += 2;
+ }
+ }
+
+ while (i < length) {
+ status = i2c_smbus_read_byte_data(client, command + i);
+ if (status < 0)
+ return status;
+ values[i] = status;
+ i++;
+ }
+
+ return i;
+}
+EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data_or_emulated);
+
#if IS_ENABLED(CONFIG_I2C_SLAVE)
int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb)
{
return -EINVAL;
}
+ if (!(client->flags & I2C_CLIENT_SLAVE))
+ dev_warn(&client->dev, "%s: client slave flag not set. You might see address collisions\n",
+ __func__);
+
if (!(client->flags & I2C_CLIENT_TEN)) {
/* Enforce stricter address checking */
- ret = i2c_check_addr_validity(client->addr);
+ ret = i2c_check_7bit_addr_validity_strict(client->addr);
if (ret) {
dev_err(&client->dev, "%s: invalid address\n", __func__);
return ret;
projects / firefly-linux-kernel-4.4.55.git / blobdiff