From 399dee2371787825a1845de87c0cbee7b7c30ad6 Mon Sep 17 00:00:00 2001 From: Ben Dooks Date: Mon, 28 Jul 2008 12:04:06 +0100 Subject: [PATCH 1/5] i2c: S3C2410: Pass the I2C bus number via drivers platform data Allow the platform data to specify the bus bumber that the new I2C bus will be given. This is to allow the use of the board registration mechanism to specify the new style of I2C device registration which allows boards to provide a list of attached devices. Note, as discussed on the mailing list, we have dropped backwards compatibility of adding an dynamic bus number as it should not affect most boards to have the bus pinned to 0 if they have either not specified platform data for driver. Any board supplying platform data will automatically have the bus_num field set to 0, and anyone who needs the driver on a different bus number can supply platform data to set bus_num. Signed-off-by: Ben Dooks --- drivers/i2c/busses/i2c-s3c2410.c | 13 ++++++++++++- include/asm-arm/plat-s3c/iic.h | 1 + 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c index 007390ad981..eef35d3f607 100644 --- a/drivers/i2c/busses/i2c-s3c2410.c +++ b/drivers/i2c/busses/i2c-s3c2410.c @@ -752,9 +752,12 @@ 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; @@ -832,7 +835,15 @@ 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); + /* 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_irq; diff --git a/include/asm-arm/plat-s3c/iic.h b/include/asm-arm/plat-s3c/iic.h index 71211c8b538..d08a1f2863e 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 */ From 1efe7c55d2c4acc6c1d1c1a68bd9070f13815272 Mon Sep 17 00:00:00 2001 From: Ben Dooks Date: Mon, 28 Jul 2008 12:04:09 +0100 Subject: [PATCH 2/5] i2c: i2c_gpio: keep probe resident for hotplugged devices. Change the i2c_gpio driver to use platform_driver_register() instead of platform_driver_probe() to ensure that is can attach to any devices that may be loaded after it has initialised. Acked-by: Haavard Skinnemoen Signed-off-by: Ben Dooks --- drivers/i2c/busses/i2c-gpio.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-gpio.c b/drivers/i2c/busses/i2c-gpio.c index 79b455a1f09..32104eac8d3 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); From 61c7cff89224fc5651b5ba5ff2185d19304b2484 Mon Sep 17 00:00:00 2001 From: Ben Dooks Date: Mon, 28 Jul 2008 12:04:07 +0100 Subject: [PATCH 3/5] i2c: S3C24XX I2C frequency scaling support. Add support for CPU frequency scaling to the S3C24XX I2C driver. Signed-off-by: Ben Dooks --- drivers/i2c/busses/i2c-s3c2410.c | 116 +++++++++++++++++++++++++++---- 1 file changed, 103 insertions(+), 13 deletions(-) diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c index eef35d3f607..4864723c742 100644 --- a/drivers/i2c/busses/i2c-s3c2410.c +++ b/drivers/i2c/busses/i2c-s3c2410.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include @@ -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 */ @@ -835,6 +914,12 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev) dev_dbg(&pdev->dev, "irq resource %p (%lu)\n", res, (unsigned long)res->start); + ret = s3c24xx_i2c_register_cpufreq(i2c); + if (ret < 0) { + 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 @@ -846,7 +931,7 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev) ret = i2c_add_numbered_adapter(&i2c->adap); if (ret < 0) { dev_err(&pdev->dev, "failed to add bus to i2c core\n"); - goto err_irq; + goto err_cpufreq; } platform_set_drvdata(pdev, i2c); @@ -854,6 +939,9 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev) 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); @@ -881,6 +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); From 31321b76e1a2c70f4eb4c0e19f9f860dcd0ef2ce Mon Sep 17 00:00:00 2001 From: Ben Dooks Date: Mon, 28 Jul 2008 12:04:08 +0100 Subject: [PATCH 4/5] i2c: Documentation: upgrading clients HOWTO Add a document describing how i2c clients on Linux 2.6 can be moved from the old to the new driver model. Signed-off-by: Ben Dooks --- Documentation/i2c/upgrading-clients | 281 ++++++++++++++++++++++++++++ 1 file changed, 281 insertions(+) create mode 100644 Documentation/i2c/upgrading-clients diff --git a/Documentation/i2c/upgrading-clients b/Documentation/i2c/upgrading-clients new file mode 100644 index 00000000000..9a45f9bb6a2 --- /dev/null +++ b/Documentation/i2c/upgrading-clients @@ -0,0 +1,281 @@ +Upgrading I2C Drivers to the new 2.6 Driver Model +================================================= + +Ben Dooks + +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, +}; From 958585f58f675a3c2855c7d91b6fdd2875552d0b Mon Sep 17 00:00:00 2001 From: Michael Hennerich Date: Sun, 27 Jul 2008 14:41:54 +0800 Subject: [PATCH 5/5] i2c: Blackfin I2C Driver: Functional power management support PM_SUSPEND_MEM: Blackfin does not maintain register state through Hibernate. Save and restore peripheral base initialization during PM transitions. Signed-off-by: Michael Hennerich Signed-off-by: Bryan Wu Signed-off-by: Ben Dooks --- drivers/i2c/busses/i2c-bfin-twi.c | 35 +++++++++++++++++++++---------- 1 file changed, 24 insertions(+), 11 deletions(-) diff --git a/drivers/i2c/busses/i2c-bfin-twi.c b/drivers/i2c/busses/i2c-bfin-twi.c index 48d084bdf7c..3c855ff2992 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; }