Re: [PATCH v2 1/4] mfd: lpc_sch: reduce duplicate code and improve manageability

[Lee Jones]

On Tue, 02 Sep 2014, Andy Shevchenko wrote:

> This patch refactors the driver to use helper functions instead of
> copy'n'pasted pieces of code.
> 
> It also introduces an additional struct to hold a chipset info. The chipset
> info will be used to store features that are supported by specific processor or
> chipset. LPC_SCH supports SMBUS, GPIO and WDT features. As this code base might
> expand further to support more processors, this implementation will help to
> keep code base clean and manageable.
> 
> The patch is partially based on the work done by Chang Rebecca Swee Fun.
> 
> Tested-by: Chang Rebecca Swee Fun <rebecca.swee.fun.chang@xxxxxxxxx>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> ---
>  drivers/mfd/lpc_sch.c | 181 +++++++++++++++++++++++++++-----------------------
>  1 file changed, 99 insertions(+), 82 deletions(-)

Applied, thanks.

> diff --git a/drivers/mfd/lpc_sch.c b/drivers/mfd/lpc_sch.c
> index 4ee7550..bde070a 100644
> --- a/drivers/mfd/lpc_sch.c
> +++ b/drivers/mfd/lpc_sch.c
> @@ -40,120 +40,137 @@
>  #define WDTBASE		0x84
>  #define WDT_IO_SIZE	64
>  
> -static struct resource smbus_sch_resource = {
> -		.flags = IORESOURCE_IO,
> +enum sch_chipsets {
> +	LPC_SCH = 0,		/* Intel Poulsbo SCH */
> +	LPC_ITC,		/* Intel Tunnel Creek */
> +	LPC_CENTERTON,		/* Intel Centerton */
>  };
>  
> -static struct resource gpio_sch_resource = {
> -		.flags = IORESOURCE_IO,
> +struct lpc_sch_info {
> +	unsigned int io_size_smbus;
> +	unsigned int io_size_gpio;
> +	unsigned int io_size_wdt;
>  };
>  
> -static struct resource wdt_sch_resource = {
> -		.flags = IORESOURCE_IO,
> -};
> -
> -static struct mfd_cell lpc_sch_cells[3];
> -
> -static struct mfd_cell isch_smbus_cell = {
> -	.name = "isch_smbus",
> -	.num_resources = 1,
> -	.resources = &smbus_sch_resource,
> -	.ignore_resource_conflicts = true,
> -};
> -
> -static struct mfd_cell sch_gpio_cell = {
> -	.name = "sch_gpio",
> -	.num_resources = 1,
> -	.resources = &gpio_sch_resource,
> -	.ignore_resource_conflicts = true,
> -};
> -
> -static struct mfd_cell wdt_sch_cell = {
> -	.name = "ie6xx_wdt",
> -	.num_resources = 1,
> -	.resources = &wdt_sch_resource,
> -	.ignore_resource_conflicts = true,
> +static struct lpc_sch_info sch_chipset_info[] = {
> +	[LPC_SCH] = {
> +		.io_size_smbus = SMBUS_IO_SIZE,
> +		.io_size_gpio = GPIO_IO_SIZE,
> +	},
> +	[LPC_ITC] = {
> +		.io_size_smbus = SMBUS_IO_SIZE,
> +		.io_size_gpio = GPIO_IO_SIZE,
> +		.io_size_wdt = WDT_IO_SIZE,
> +	},
> +	[LPC_CENTERTON] = {
> +		.io_size_smbus = SMBUS_IO_SIZE,
> +		.io_size_gpio = GPIO_IO_SIZE_CENTERTON,
> +		.io_size_wdt = WDT_IO_SIZE,
> +	},
>  };
>  
>  static const struct pci_device_id lpc_sch_ids[] = {
> -	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_SCH_LPC) },
> -	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ITC_LPC) },
> -	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_CENTERTON_ILB) },
> +	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_SCH_LPC), LPC_SCH },
> +	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ITC_LPC), LPC_ITC },
> +	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_CENTERTON_ILB), LPC_CENTERTON },
>  	{ 0, }
>  };
>  MODULE_DEVICE_TABLE(pci, lpc_sch_ids);
>  
> -static int lpc_sch_probe(struct pci_dev *dev,
> -				const struct pci_device_id *id)
> +#define LPC_NO_RESOURCE		1
> +#define LPC_SKIP_RESOURCE	2
> +
> +static int lpc_sch_get_io(struct pci_dev *pdev, int where, const char *name,
> +			  struct resource *res, int size)
>  {
>  	unsigned int base_addr_cfg;
>  	unsigned short base_addr;
> -	int i, cells = 0;
> -	int ret;
>  
> -	pci_read_config_dword(dev, SMBASE, &base_addr_cfg);
> +	if (size == 0)
> +		return LPC_NO_RESOURCE;
> +
> +	pci_read_config_dword(pdev, where, &base_addr_cfg);
>  	base_addr = 0;
>  	if (!(base_addr_cfg & (1 << 31)))
> -		dev_warn(&dev->dev, "Decode of the SMBus I/O range disabled\n");
> +		dev_warn(&pdev->dev, "Decode of the %s I/O range disabled\n",
> +			 name);
>  	else
>  		base_addr = (unsigned short)base_addr_cfg;
>  
>  	if (base_addr == 0) {
> -		dev_warn(&dev->dev, "I/O space for SMBus uninitialized\n");
> -	} else {
> -		lpc_sch_cells[cells++] = isch_smbus_cell;
> -		smbus_sch_resource.start = base_addr;
> -		smbus_sch_resource.end = base_addr + SMBUS_IO_SIZE - 1;
> +		dev_warn(&pdev->dev, "I/O space for %s uninitialized\n", name);
> +		return LPC_SKIP_RESOURCE;
>  	}
>  
> -	pci_read_config_dword(dev, GPIOBASE, &base_addr_cfg);
> -	base_addr = 0;
> -	if (!(base_addr_cfg & (1 << 31)))
> -		dev_warn(&dev->dev, "Decode of the GPIO I/O range disabled\n");
> -	else
> -		base_addr = (unsigned short)base_addr_cfg;
> +	res->start = base_addr;
> +	res->end = base_addr + size - 1;
> +	res->flags = IORESOURCE_IO;
>  
> -	if (base_addr == 0) {
> -		dev_warn(&dev->dev, "I/O space for GPIO uninitialized\n");
> -	} else {
> -		lpc_sch_cells[cells++] = sch_gpio_cell;
> -		gpio_sch_resource.start = base_addr;
> -		if (id->device == PCI_DEVICE_ID_INTEL_CENTERTON_ILB)
> -			gpio_sch_resource.end = base_addr + GPIO_IO_SIZE_CENTERTON - 1;
> -		else
> -			gpio_sch_resource.end = base_addr + GPIO_IO_SIZE - 1;
> -	}
> +	return 0;
> +}
>  
> -	if (id->device == PCI_DEVICE_ID_INTEL_ITC_LPC
> -	    || id->device == PCI_DEVICE_ID_INTEL_CENTERTON_ILB) {
> -		pci_read_config_dword(dev, WDTBASE, &base_addr_cfg);
> -		base_addr = 0;
> -		if (!(base_addr_cfg & (1 << 31)))
> -			dev_warn(&dev->dev, "Decode of the WDT I/O range disabled\n");
> -		else
> -			base_addr = (unsigned short)base_addr_cfg;
> -		if (base_addr == 0)
> -			dev_warn(&dev->dev, "I/O space for WDT uninitialized\n");
> -		else {
> -			lpc_sch_cells[cells++] = wdt_sch_cell;
> -			wdt_sch_resource.start = base_addr;
> -			wdt_sch_resource.end = base_addr + WDT_IO_SIZE - 1;
> -		}
> -	}
> +static int lpc_sch_populate_cell(struct pci_dev *pdev, int where,
> +				 const char *name, int size, int id,
> +				 struct mfd_cell *cell)
> +{
> +	struct resource *res;
> +	int ret;
>  
> -	if (WARN_ON(cells > ARRAY_SIZE(lpc_sch_cells))) {
> -		dev_err(&dev->dev, "Cell count exceeds array size");
> -		return -ENODEV;
> -	}
> +	res = devm_kzalloc(&pdev->dev, sizeof(*res), GFP_KERNEL);
> +	if (!res)
> +		return -ENOMEM;
> +
> +	ret = lpc_sch_get_io(pdev, where, name, res, size);
> +	if (ret)
> +		return ret;
> +
> +	memset(cell, 0, sizeof(*cell));
> +
> +	cell->name = name;
> +	cell->resources = res;
> +	cell->num_resources = 1;
> +	cell->ignore_resource_conflicts = true;
> +	cell->id = id;
> +
> +	return 0;
> +}
> +
> +static int lpc_sch_probe(struct pci_dev *dev, const struct pci_device_id *id)
> +{
> +	struct mfd_cell lpc_sch_cells[3];
> +	struct lpc_sch_info *info = &sch_chipset_info[id->driver_data];
> +	unsigned int cells = 0;
> +	int ret;
> +
> +	ret = lpc_sch_populate_cell(dev, SMBASE, "isch_smbus",
> +				    info->io_size_smbus,
> +				    id->device, &lpc_sch_cells[cells]);
> +	if (ret < 0)
> +		return ret;
> +	if (ret == 0)
> +		cells++;
> +
> +	ret = lpc_sch_populate_cell(dev, GPIOBASE, "sch_gpio",
> +				    info->io_size_gpio,
> +				    id->device, &lpc_sch_cells[cells]);
> +	if (ret < 0)
> +		return ret;
> +	if (ret == 0)
> +		cells++;
> +
> +	ret = lpc_sch_populate_cell(dev, WDTBASE, "ie6xx_wdt",
> +				    info->io_size_wdt,
> +				    id->device, &lpc_sch_cells[cells]);
> +	if (ret < 0)
> +		return ret;
> +	if (ret == 0)
> +		cells++;
>  
>  	if (cells == 0) {
>  		dev_err(&dev->dev, "All decode registers disabled.\n");
>  		return -ENODEV;
>  	}
>  
> -	for (i = 0; i < cells; i++)
> -		lpc_sch_cells[i].id = id->device;
> -
>  	ret = mfd_add_devices(&dev->dev, 0, lpc_sch_cells, cells, NULL, 0, NULL);
>  	if (ret)
>  		mfd_remove_devices(&dev->dev);

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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