[PATCH] i2c: pxa: create dynamic platform device from device tree

[grant.likely@secretlab.ca (Grant Likely)]

On Fri, Jul 08, 2011 at 06:20:23PM +0800, Haojian Zhuang wrote:
> Create two probe function to support both current platform device and created
> dynamic platform device from device tree. After moving to device tree,
> original implementation of platform device will be removed.
> 
> Use property to present polling mode and frequency mode.
> 
> Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
> ---
>  drivers/i2c/busses/i2c-pxa.c |  163 ++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 163 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
> index d603646..7a6d774 100644
> --- a/drivers/i2c/busses/i2c-pxa.c
> +++ b/drivers/i2c/busses/i2c-pxa.c
> @@ -29,6 +29,7 @@
>  #include <linux/errno.h>
>  #include <linux/interrupt.h>
>  #include <linux/i2c-pxa.h>
> +#include <linux/of_device.h>
>  #include <linux/of_i2c.h>
>  #include <linux/platform_device.h>
>  #include <linux/err.h>
> @@ -1044,6 +1045,162 @@ static const struct i2c_algorithm i2c_pxa_pio_algorithm = {
>  	.functionality	= i2c_pxa_functionality,
>  };
>  
> +static const struct of_device_id pxa_i2c_of_match[] = {
> +	{ .compatible = "pxa2xx-i2c",	.data = (void *)REGS_PXA2XX, },
> +	{ .compatible = "pxa3xx-pwri2c", .data = (void *)REGS_PXA3XX, },
> +	{ .compatible = "ce4100-i2c",	.data = (void *)REGS_CE4100, },

New compatible values need to be written up in
Documentation/devicetree/bindings, and strings should be in the form
"<vendor>,<soc>-i2c".  They should also be specific to the soc instead
of trying to be generic (ie. use "marvell,pxa255-i2c" instead of
"marvell,pxa2xx-i2c".

> +	{},
> +};
> +
> +#ifdef CONFIG_OF
> +static int i2c_pxa_of_probe(struct platform_device *of_dev)
> +{

CONFIG_OF should not be an either/or option.  Turning on CONFIG_OF
must not disable non-DT users.

> +	struct device_node *np = of_dev->dev.of_node;
> +	const struct of_device_id *match;
> +	struct i2c_pxa_platform_data *plat = NULL;
> +	struct pxa_i2c *i2c;
> +	struct resource *res;
> +	const __be32 *p;
> +	int i2c_type, irq, data, ret;
> +	int id = 0, poll = 0, fast = 0;
> +
> +	match = of_match_device(pxa_i2c_of_match, &of_dev->dev);
> +	if (match == NULL)
> +		return -ENODEV;
> +	i2c_type = (int)match->data;
> +
> +	p = of_get_property(np, "cell-index", &data);
> +	if (p)
> +		id = be32_to_cpu(*p);

When using the device tree, the bus id should be dynamically
assigned.  Don't use a cell-index property.

> +
> +	p = of_get_property(np, "i2c-polling", &data);
> +	if (p)
> +		poll = be32_to_cpu(*p);
> +
> +	p = of_get_property(np, "i2c-frequency", &data);
> +	if (p && !strncmp((char *)p, "fast", data))
> +		fast = 1;
> +
> +	res = platform_get_resource(of_dev, IORESOURCE_MEM, 0);
> +	irq = platform_get_irq(of_dev, 0);
> +	if (res == NULL || irq < 0)
> +		return -ENODEV;
> +
> +	if (!request_mem_region(res->start, resource_size(res), res->name))
> +		return -ENOMEM;
> +
> +	i2c = kzalloc(sizeof(struct pxa_i2c), GFP_KERNEL);

kzalloc(sizeof(*i2c), GFP_KERNEL)

> +	if (!i2c) {
> +		ret = -ENOMEM;
> +		goto emalloc;
> +	}
> +
> +	i2c->adap.owner   = THIS_MODULE;
> +	i2c->adap.retries = 5;
> +
> +	spin_lock_init(&i2c->lock);
> +	init_waitqueue_head(&i2c->wait);
> +
> +	/*
> +	 * adap.nr comes from cell-index in dts file
> +	 */
> +	i2c->adap.nr = id;
> +	snprintf(i2c->adap.name, sizeof(i2c->adap.name), "pxa2xx-i2c.%u",
> +		 i2c->adap.nr);
> +
> +	i2c->clk = clk_get_sys(i2c->adap.name, NULL);
> +	if (IS_ERR(i2c->clk)) {
> +		ret = PTR_ERR(i2c->clk);
> +		goto eclk;
> +	}
> +
> +	i2c->reg_base = ioremap(res->start, resource_size(res));
> +	if (!i2c->reg_base) {
> +		ret = -EIO;
> +		goto eremap;
> +	}
> +
> +	i2c->reg_ibmr = i2c->reg_base + pxa_reg_layout[i2c_type].ibmr;
> +	i2c->reg_idbr = i2c->reg_base + pxa_reg_layout[i2c_type].idbr;
> +	i2c->reg_icr = i2c->reg_base + pxa_reg_layout[i2c_type].icr;
> +	i2c->reg_isr = i2c->reg_base + pxa_reg_layout[i2c_type].isr;
> +	if (i2c_type != REGS_CE4100)
> +		i2c->reg_isar = i2c->reg_base + pxa_reg_layout[i2c_type].isar;
> +
> +	i2c->iobase = res->start;
> +	i2c->iosize = resource_size(res);
> +
> +	i2c->irq = irq;
> +	i2c->use_pio = poll;
> +	i2c->fast_mode = fast;
> +
> +	i2c->slave_addr = I2C_PXA_SLAVE_ADDR;
> +
> +#ifdef CONFIG_I2C_PXA_SLAVE
> +	if (plat) {
> +		i2c->slave_addr = plat->slave_addr;
> +		i2c->slave = plat->slave;
> +	}
> +#endif
> +
> +	clk_enable(i2c->clk);
> +
> +	if (plat)
> +		i2c->adap.class = plat->class;
> +
> +	if (i2c->use_pio) {
> +		i2c->adap.algo = &i2c_pxa_pio_algorithm;
> +	} else {
> +		i2c->adap.algo = &i2c_pxa_algorithm;
> +		ret = request_irq(irq, i2c_pxa_handler, IRQF_SHARED,
> +				  i2c->adap.name, i2c);
> +		if (ret)
> +			goto ereqirq;
> +	}
> +
> +	i2c_pxa_reset(i2c);
> +
> +	i2c->adap.algo_data = i2c;
> +	i2c->adap.dev.parent = &of_dev->dev;
> +	i2c->adap.dev.of_node = of_dev->dev.of_node;
> +
> +	if (i2c_type == REGS_CE4100)
> +		ret = i2c_add_adapter(&i2c->adap);
> +	else
> +		ret = i2c_add_numbered_adapter(&i2c->adap);
> +	if (ret < 0) {
> +		printk(KERN_INFO "I2C: Failed to add bus\n");
> +		goto eadapt;
> +	}
> +	of_i2c_register_devices(&i2c->adap);
> +
> +	platform_set_drvdata(of_dev, i2c);
> +
> +#ifdef CONFIG_I2C_PXA_SLAVE
> +	printk(KERN_INFO "I2C: %s: PXA I2C adapter, slave address %d\n",
> +	       dev_name(&i2c->adap.dev), i2c->slave_addr);
> +#else
> +	printk(KERN_INFO "I2C: %s: PXA I2C adapter\n",
> +	       dev_name(&i2c->adap.dev));
> +#endif
> +	return 0;
> +
> +eadapt:
> +	if (!i2c->use_pio)
> +		free_irq(irq, i2c);
> +ereqirq:
> +	clk_disable(i2c->clk);
> +	iounmap(i2c->reg_base);
> +eremap:
> +	clk_put(i2c->clk);
> +eclk:
> +	kfree(i2c);
> +emalloc:
> +	release_mem_region(res->start, resource_size(res));
> +	return ret;
> +}
> +#else
> +
>  static int i2c_pxa_probe(struct platform_device *dev)
>  {
>  	struct pxa_i2c *i2c;
> @@ -1174,6 +1331,7 @@ emalloc:
>  	release_mem_region(res->start, resource_size(res));
>  	return ret;
>  }
> +#endif
>  
>  static int __exit i2c_pxa_remove(struct platform_device *dev)
>  {
> @@ -1228,12 +1386,17 @@ static const struct dev_pm_ops i2c_pxa_dev_pm_ops = {
>  #endif
>  
>  static struct platform_driver i2c_pxa_driver = {
> +#ifdef CONFIG_OF
> +	.probe		= i2c_pxa_of_probe,
> +#else
>  	.probe		= i2c_pxa_probe,
> +#endif
>  	.remove		= __exit_p(i2c_pxa_remove),
>  	.driver		= {
>  		.name	= "pxa2xx-i2c",
>  		.owner	= THIS_MODULE,
>  		.pm	= I2C_PXA_DEV_PM_OPS,
> +		.of_match_table	= pxa_i2c_of_match,
>  	},
>  	.id_table	= i2c_pxa_id_table,
>  };
> -- 
> 1.5.6.5
>