The following changes since commit c9272c4f9fbe2087beb3392f526dc5b19efaa56b:
Linus Torvalds (1):
Merge branch 'hotfixes' of
git://git.linux-nfs.org/projects/trondmy/nfs-2.6
are available in the git repository at:
git://aeryn.fluff.org.uk/bjdooks/linux.git i2c-for-linus
Ben Dooks (4):
i2c: S3C2410: Pass the I2C bus number via drivers platform data
i2c: i2c_gpio: keep probe resident for hotplugged devices.
i2c: S3C24XX I2C frequency scaling support.
i2c: Documentation: upgrading clients HOWTO
Michael Hennerich (1):
i2c: Blackfin I2C Driver: Functional power management support
Documentation/i2c/upgrading-clients | 281 +++++++++++++++++++++++++++++++++++
drivers/i2c/busses/i2c-bfin-twi.c | 35 +++--
drivers/i2c/busses/i2c-gpio.c | 9 +-
drivers/i2c/busses/i2c-s3c2410.c | 129 ++++++++++++++--
include/asm-arm/plat-s3c/iic.h | 1 +
5 files changed, 426 insertions(+), 29 deletions(-)
create mode 100644 Documentation/i2c/upgrading-clients
diff --git a/Documentation/i2c/upgrading-clients
b/Documentation/i2c/upgrading-clients
new file mode 100644
index 0000000..9a45f9b
--- /dev/null
+++ b/Documentation/i2c/upgrading-clients
@@ -0,0 +1,281 @@
+Upgrading I2C Drivers to the new 2.6 Driver Model
+=================================================
+
+Ben Dooks <[EMAIL PROTECTED]>
+
+Introduction
+------------
+
+This guide outlines how to alter existing Linux 2.6 client drivers from
+the old to the new new binding methods.
+
+
+Example old-style driver
+------------------------
+
+
+struct example_state {
+ struct i2c_client client;
+ ....
+};
+
+static struct i2c_driver example_driver;
+
+static unsigned short ignore[] = { I2C_CLIENT_END };
+static unsigned short normal_addr[] = { OUR_ADDR, I2C_CLIENT_END };
+
+I2C_CLIENT_INSMOD;
+
+static int example_attach(struct i2c_adapter *adap, int addr, int kind)
+{
+ struct example_state *state;
+ struct device *dev = &adap->dev; /* to use for dev_ reports */
+ int ret;
+
+ state = kzalloc(sizeof(struct example_state), GFP_KERNEL);
+ if (state == NULL) {
+ dev_err(dev, "failed to create our state\n");
+ return -ENOMEM;
+ }
+
+ example->client.addr = addr;
+ example->client.flags = 0;
+ example->client.adapter = adap;
+
+ i2c_set_clientdata(&state->i2c_client, state);
+ strlcpy(client->i2c_client.name, "example", I2C_NAME_SIZE);
+
+ ret = i2c_attach_client(&state->i2c_client);
+ if (ret < 0) {
+ dev_err(dev, "failed to attach client\n");
+ kfree(state);
+ return ret;
+ }
+
+ dev = &state->i2c_client.dev;
+
+ /* rest of the initialisation goes here. */
+
+ dev_info(dev, "example client created\n");
+
+ return 0;
+}
+
+static int __devexit example_detach(struct i2c_client *client)
+{
+ struct example_state *state = i2c_get_clientdata(client);
+
+ i2c_detach_client(client);
+ kfree(state);
+ return 0;
+}
+
+static int example_attach_adapter(struct i2c_adapter *adap)
+{
+ return i2c_probe(adap, &addr_data, example_attach);
+}
+
+static struct i2c_driver example_driver = {
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "example",
+ },
+ .attach_adapter = example_attach_adapter,
+ .detach_client = __devexit_p(example_detach),
+ .suspend = example_suspend,
+ .resume = example_resume,
+};
+
+
+Updating the client
+-------------------
+
+The new style binding model will check against a list of supported
+devices and their associated address supplied by the code registering
+the busses. This means that the driver .attach_adapter and
+.detach_adapter methods can be removed, along with the addr_data,
+as follows:
+
+- static struct i2c_driver example_driver;
+
+- static unsigned short ignore[] = { I2C_CLIENT_END };
+- static unsigned short normal_addr[] = { OUR_ADDR, I2C_CLIENT_END };
+
+- I2C_CLIENT_INSMOD;
+
+- static int example_attach_adapter(struct i2c_adapter *adap)
+- {
+- return i2c_probe(adap, &addr_data, example_attach);
+- }
+
+ static struct i2c_driver example_driver = {
+- .attach_adapter = example_attach_adapter,
+- .detach_client = __devexit_p(example_detach),
+ }
+
+Add the probe and remove methods to the i2c_driver, as so:
+
+ static struct i2c_driver example_driver = {
++ .probe = example_probe,
++ .remove = __devexit_p(example_remove),
+ }
+
+Change the example_attach method to accept the new parameters
+which include the i2c_client that it will be working with:
+
+- static int example_attach(struct i2c_adapter *adap, int addr, int kind)
++ static int example_probe(struct i2c_client *client,
++ const struct i2c_device_id *id)
+
+Change the name of example_attach to example_probe to align it with the
+i2c_driver entry names. The rest of the probe routine will now need to be
+changed as the i2c_client has already been setup for use.
+
+The necessary client fields have already been setup before
+the probe function is called, so the following client setup
+can be removed:
+
+- example->client.addr = addr;
+- example->client.flags = 0;
+- example->client.adapter = adap;
+-
+- strlcpy(client->i2c_client.name, "example", I2C_NAME_SIZE);
+
+The i2c_set_clientdata is now:
+
+- i2c_set_clientdata(&state->client, state);
++ i2c_set_clientdata(client, state);
+
+The call to i2c_attach_client is no longer needed, if the probe
+routine exits successfully, then the driver will be automatically
+attached by the core. Change the probe routine as so:
+
+- ret = i2c_attach_client(&state->i2c_client);
+- if (ret < 0) {
+- dev_err(dev, "failed to attach client\n");
+- kfree(state);
+- return ret;
+- }
+
+
+Remove the storage of 'struct i2c_client' from the 'struct example_state'
+as we are provided with the i2c_client in our example_probe. Instead we
+store a pointer to it for when it is needed.
+
+struct example_state {
+- struct i2c_client client;
++ struct i2c_client *client;
+
+the new i2c client as so:
+
+- struct device *dev = &adap->dev; /* to use for dev_ reports */
++ struct device *dev = &i2c_client->dev; /* to use for dev_ reports */
+
+And remove the change after our client is attached, as the driver no
+longer needs to register a new client structure with the core:
+
+- dev = &state->i2c_client.dev;
+
+In the probe routine, ensure that the new state has the client stored
+in it:
+
+static int example_probe(struct i2c_client *i2c_client,
+ const struct i2c_device_id *id)
+{
+ struct example_state *state;
+ struct device *dev = &i2c_client->dev;
+ int ret;
+
+ state = kzalloc(sizeof(struct example_state), GFP_KERNEL);
+ if (state == NULL) {
+ dev_err(dev, "failed to create our state\n");
+ return -ENOMEM;
+ }
+
++ state->client = i2c_client;
+
+Update the detach method, by changing the name to _remove and
+to delete the i2c_detach_client call. It is possible that you
+can also remove the ret variable as it is not not needed for
+any of the core functions.
+
+- static int __devexit example_detach(struct i2c_client *client)
++ static int __devexit example_remove(struct i2c_client *client)
+{
+ struct example_state *state = i2c_get_clientdata(client);
+
+- i2c_detach_client(client);
+
+And finally ensure that we have the correct ID table for the i2c-core
+and other utilities:
+
++ struct i2c_device_id example_idtable[] = {
++ { "example", 0 },
++ { }
++};
++
++MODULE_DEVICE_TABLE(i2c, example_idtable);
+
+static struct i2c_driver example_driver = {
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "example",
+ },
++ .id_table = example_ids,
+
+
+Our driver should now look like this:
+
+struct example_state {
+ struct i2c_client *client;
+ ....
+};
+
+static int example_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct example_state *state;
+ struct device *dev = &client->dev;
+
+ state = kzalloc(sizeof(struct example_state), GFP_KERNEL);
+ if (state == NULL) {
+ dev_err(dev, "failed to create our state\n");
+ return -ENOMEM;
+ }
+
+ state->client = client;
+ i2c_set_clientdata(client, state);
+
+ /* rest of the initialisation goes here. */
+
+ dev_info(dev, "example client created\n");
+
+ return 0;
+}
+
+static int __devexit example_remove(struct i2c_client *client)
+{
+ struct example_state *state = i2c_get_clientdata(client);
+
+ kfree(state);
+ return 0;
+}
+
+static struct i2c_device_id example_idtable[] = {
+ { "example", 0 },
+ { }
+};
+
+MODULE_DEVICE_TABLE(i2c, example_idtable);
+
+static struct i2c_driver example_driver = {
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "example",
+ },
+ .id_table = example_idtable,
+ .probe = example_probe,
+ .remove = __devexit_p(example_remove),
+ .suspend = example_suspend,
+ .resume = example_resume,
+};
diff --git a/drivers/i2c/busses/i2c-bfin-twi.c
b/drivers/i2c/busses/i2c-bfin-twi.c
index 48d084b..3c855ff 100644
--- a/drivers/i2c/busses/i2c-bfin-twi.c
+++ b/drivers/i2c/busses/i2c-bfin-twi.c
@@ -49,6 +49,8 @@ struct bfin_twi_iface {
struct i2c_msg *pmsg;
int msg_num;
int cur_msg;
+ u16 saved_clkdiv;
+ u16 saved_control;
void __iomem *regs_base;
};
@@ -565,32 +567,43 @@ static u32 bfin_twi_functionality(struct i2c_adapter
*adap)
I2C_FUNC_I2C;
}
-
static struct i2c_algorithm bfin_twi_algorithm = {
.master_xfer = bfin_twi_master_xfer,
.smbus_xfer = bfin_twi_smbus_xfer,
.functionality = bfin_twi_functionality,
};
-
-static int i2c_bfin_twi_suspend(struct platform_device *dev, pm_message_t
state)
+static int i2c_bfin_twi_suspend(struct platform_device *pdev, pm_message_t
state)
{
- struct bfin_twi_iface *iface = platform_get_drvdata(dev);
+ struct bfin_twi_iface *iface = platform_get_drvdata(pdev);
+
+ iface->saved_clkdiv = read_CLKDIV(iface);
+ iface->saved_control = read_CONTROL(iface);
+
+ free_irq(iface->irq, iface);
/* Disable TWI */
- write_CONTROL(iface, read_CONTROL(iface) & ~TWI_ENA);
- SSYNC();
+ write_CONTROL(iface, iface->saved_control & ~TWI_ENA);
return 0;
}
-static int i2c_bfin_twi_resume(struct platform_device *dev)
+static int i2c_bfin_twi_resume(struct platform_device *pdev)
{
- struct bfin_twi_iface *iface = platform_get_drvdata(dev);
+ struct bfin_twi_iface *iface = platform_get_drvdata(pdev);
- /* Enable TWI */
- write_CONTROL(iface, read_CONTROL(iface) | TWI_ENA);
- SSYNC();
+ int rc = request_irq(iface->irq, bfin_twi_interrupt_entry,
+ IRQF_DISABLED, pdev->name, iface);
+ if (rc) {
+ dev_err(&pdev->dev, "Can't get IRQ %d !\n", iface->irq);
+ return -ENODEV;
+ }
+
+ /* Resume TWI interface clock as specified */
+ write_CLKDIV(iface, iface->saved_clkdiv);
+
+ /* Resume TWI */
+ write_CONTROL(iface, iface->saved_control);
return 0;
}
diff --git a/drivers/i2c/busses/i2c-gpio.c b/drivers/i2c/busses/i2c-gpio.c
index 79b455a..32104ea 100644
--- a/drivers/i2c/busses/i2c-gpio.c
+++ b/drivers/i2c/busses/i2c-gpio.c
@@ -77,7 +77,7 @@ static int i2c_gpio_getscl(void *data)
return gpio_get_value(pdata->scl_pin);
}
-static int __init i2c_gpio_probe(struct platform_device *pdev)
+static int __devinit i2c_gpio_probe(struct platform_device *pdev)
{
struct i2c_gpio_platform_data *pdata;
struct i2c_algo_bit_data *bit_data;
@@ -174,7 +174,7 @@ err_alloc_adap:
return ret;
}
-static int __exit i2c_gpio_remove(struct platform_device *pdev)
+static int __devexit i2c_gpio_remove(struct platform_device *pdev)
{
struct i2c_gpio_platform_data *pdata;
struct i2c_adapter *adap;
@@ -196,14 +196,15 @@ static struct platform_driver i2c_gpio_driver = {
.name = "i2c-gpio",
.owner = THIS_MODULE,
},
- .remove = __exit_p(i2c_gpio_remove),
+ .probe = i2c_gpio_probe,
+ .remove = __devexit_p(i2c_gpio_remove),
};
static int __init i2c_gpio_init(void)
{
int ret;
- ret = platform_driver_probe(&i2c_gpio_driver, i2c_gpio_probe);
+ ret = platform_driver_register(&i2c_gpio_driver);
if (ret)
printk(KERN_ERR "i2c-gpio: probe failed: %d\n", ret);
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index 007390a..4864723 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -33,6 +33,7 @@
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
+#include <linux/cpufreq.h>
#include <asm/hardware.h>
#include <asm/irq.h>
@@ -64,6 +65,7 @@ struct s3c24xx_i2c {
unsigned int tx_setup;
enum s3c24xx_i2c_state state;
+ unsigned long clkrate;
void __iomem *regs;
struct clk *clk;
@@ -71,6 +73,10 @@ struct s3c24xx_i2c {
struct resource *irq;
struct resource *ioarea;
struct i2c_adapter adap;
+
+#ifdef CONFIG_CPU_FREQ
+ struct notifier_block freq_transition;
+#endif
};
/* default platform data to use if not supplied in the platform_device
@@ -501,6 +507,9 @@ static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c,
struct i2c_msg *msgs, int
unsigned long timeout;
int ret;
+ if (!readl(i2c->regs + S3C2410_IICCON) & S3C2410_IICCON_IRQEN)
+ return -EIO;
+
ret = s3c24xx_i2c_set_master(i2c);
if (ret != 0) {
dev_err(i2c->dev, "cannot get bus (error %d)\n", ret);
@@ -636,27 +645,28 @@ static inline int freq_acceptable(unsigned int freq,
unsigned int wanted)
return (diff >= -2 && diff <= 2);
}
-/* s3c24xx_i2c_getdivisor
+/* s3c24xx_i2c_clockrate
*
* work out a divisor for the user requested frequency setting,
* either by the requested frequency, or scanning the acceptable
* range of frequencies until something is found
*/
-static int s3c24xx_i2c_getdivisor(struct s3c24xx_i2c *i2c,
- struct s3c2410_platform_i2c *pdata,
- unsigned long *iicon,
- unsigned int *got)
+static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got)
{
+ struct s3c2410_platform_i2c *pdata;
unsigned long clkin = clk_get_rate(i2c->clk);
-
unsigned int divs, div1;
+ u32 iiccon;
int freq;
int start, end;
+ i2c->clkrate = clkin;
+
+ pdata = s3c24xx_i2c_get_platformdata(i2c->adap.dev.parent);
clkin /= 1000; /* clkin now in KHz */
- dev_dbg(i2c->dev, "pdata %p, freq %lu %lu..%lu\n",
+ dev_dbg(i2c->dev, "pdata %p, freq %lu %lu..%lu\n",
pdata, pdata->bus_freq, pdata->min_freq, pdata->max_freq);
if (pdata->bus_freq != 0) {
@@ -688,11 +698,79 @@ static int s3c24xx_i2c_getdivisor(struct s3c24xx_i2c *i2c,
found:
*got = freq;
- *iicon |= (divs-1);
- *iicon |= (div1 == 512) ? S3C2410_IICCON_TXDIV_512 : 0;
+
+ iiccon = readl(i2c->regs + S3C2410_IICCON);
+ iiccon &= ~(S3C2410_IICCON_SCALEMASK | S3C2410_IICCON_TXDIV_512);
+ iiccon |= (divs-1);
+
+ if (div1 == 512)
+ iiccon |= S3C2410_IICCON_TXDIV_512;
+
+ writel(iiccon, i2c->regs + S3C2410_IICCON);
+
+ return 0;
+}
+
+#ifdef CONFIG_CPU_FREQ
+
+#define freq_to_i2c(_n) container_of(_n, struct s3c24xx_i2c, freq_transition)
+
+static int s3c24xx_i2c_cpufreq_transition(struct notifier_block *nb,
+ unsigned long val, void *data)
+{
+ struct s3c24xx_i2c *i2c = freq_to_i2c(nb);
+ unsigned long flags;
+ unsigned int got;
+ int delta_f;
+ int ret;
+
+ delta_f = clk_get_rate(i2c->clk) - i2c->clkrate;
+
+ /* if we're post-change and the input clock has slowed down
+ * or at pre-change and the clock is about to speed up, then
+ * adjust our clock rate. <0 is slow, >0 speedup.
+ */
+
+ if ((val == CPUFREQ_POSTCHANGE && delta_f < 0) ||
+ (val == CPUFREQ_PRECHANGE && delta_f > 0)) {
+ spin_lock_irqsave(&i2c->lock, flags);
+ ret = s3c24xx_i2c_clockrate(i2c, &got);
+ spin_unlock_irqrestore(&i2c->lock, flags);
+
+ if (ret < 0)
+ dev_err(i2c->dev, "cannot find frequency\n");
+ else
+ dev_info(i2c->dev, "setting freq %d\n", got);
+ }
+
+ return 0;
+}
+
+static inline int s3c24xx_i2c_register_cpufreq(struct s3c24xx_i2c *i2c)
+{
+ i2c->freq_transition.notifier_call = s3c24xx_i2c_cpufreq_transition;
+
+ return cpufreq_register_notifier(&i2c->freq_transition,
+ CPUFREQ_TRANSITION_NOTIFIER);
+}
+
+static inline void s3c24xx_i2c_deregister_cpufreq(struct s3c24xx_i2c *i2c)
+{
+ cpufreq_unregister_notifier(&i2c->freq_transition,
+ CPUFREQ_TRANSITION_NOTIFIER);
+}
+
+#else
+static inline int s3c24xx_i2c_register_cpufreq(struct s3c24xx_i2c *i2c)
+{
return 0;
}
+static inline void s3c24xx_i2c_deregister_cpufreq(struct s3c24xx_i2c *i2c)
+{
+}
+#endif
+
/* s3c24xx_i2c_init
*
* initialise the controller, set the IO lines and frequency
@@ -719,9 +797,12 @@ static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c)
dev_info(i2c->dev, "slave address 0x%02x\n", pdata->slave_addr);
+ writel(iicon, i2c->regs + S3C2410_IICCON);
+
/* we need to work out the divisors for the clock... */
- if (s3c24xx_i2c_getdivisor(i2c, pdata, &iicon, &freq) != 0) {
+ if (s3c24xx_i2c_clockrate(i2c, &freq) != 0) {
+ writel(0, i2c->regs + S3C2410_IICCON);
dev_err(i2c->dev, "cannot meet bus frequency required\n");
return -EINVAL;
}
@@ -730,8 +811,6 @@ static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c)
dev_info(i2c->dev, "bus frequency set to %d KHz\n", freq);
dev_dbg(i2c->dev, "S3C2410_IICCON=0x%02lx\n", iicon);
-
- writel(iicon, i2c->regs + S3C2410_IICCON);
/* check for s3c2440 i2c controller */
@@ -752,9 +831,12 @@ static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c)
static int s3c24xx_i2c_probe(struct platform_device *pdev)
{
struct s3c24xx_i2c *i2c = &s3c24xx_i2c;
+ struct s3c2410_platform_i2c *pdata;
struct resource *res;
int ret;
+ pdata = s3c24xx_i2c_get_platformdata(&pdev->dev);
+
/* find the clock and enable it */
i2c->dev = &pdev->dev;
@@ -832,17 +914,34 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
dev_dbg(&pdev->dev, "irq resource %p (%lu)\n", res,
(unsigned long)res->start);
- ret = i2c_add_adapter(&i2c->adap);
+ ret = s3c24xx_i2c_register_cpufreq(i2c);
if (ret < 0) {
- dev_err(&pdev->dev, "failed to add bus to i2c core\n");
+ dev_err(&pdev->dev, "failed to register cpufreq notifier\n");
goto err_irq;
}
+ /* Note, previous versions of the driver used i2c_add_adapter()
+ * to add the bus at any number. We now pass the bus number via
+ * the platform data, so if unset it will now default to always
+ * being bus 0.
+ */
+
+ i2c->adap.nr = pdata->bus_num;
+
+ ret = i2c_add_numbered_adapter(&i2c->adap);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to add bus to i2c core\n");
+ goto err_cpufreq;
+ }
+
platform_set_drvdata(pdev, i2c);
dev_info(&pdev->dev, "%s: S3C I2C adapter\n", i2c->adap.dev.bus_id);
return 0;
+ err_cpufreq:
+ s3c24xx_i2c_deregister_cpufreq(i2c);
+
err_irq:
free_irq(i2c->irq->start, i2c);
@@ -870,6 +969,8 @@ static int s3c24xx_i2c_remove(struct platform_device *pdev)
{
struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev);
+ s3c24xx_i2c_deregister_cpufreq(i2c);
+
i2c_del_adapter(&i2c->adap);
free_irq(i2c->irq->start, i2c);
diff --git a/include/asm-arm/plat-s3c/iic.h b/include/asm-arm/plat-s3c/iic.h
index 71211c8..d08a1f2 100644
--- a/include/asm-arm/plat-s3c/iic.h
+++ b/include/asm-arm/plat-s3c/iic.h
@@ -21,6 +21,7 @@
*/
struct s3c2410_platform_i2c {
+ int bus_num; /* bus number to use */
unsigned int flags;
unsigned int slave_addr; /* slave address for controller */
unsigned long bus_freq; /* standard bus frequency */
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