[PATCH v2 1/2] staging: mt7621-pci: use generic kernel pci subsystem read and write

[Sergio Paracuellos]

On Thu, Jul 12, 2018 at 09:28:15PM +0300, Dan Carpenter wrote:
> On Thu, Jul 12, 2018 at 08:15:00PM +0200, Sergio Paracuellos wrote:
> > map_bus callback is called before every .read/.write operation.
> > Implement it and change custom read write operations for the
> > pci subsystem generics. Make the probe function to assign data
> > for controller data and get pci register base from device tree.
> > 
> > Signed-off-by: Sergio Paracuellos <sergio.paracuellos at gmail.com>
> > ---
> >  drivers/staging/mt7621-pci/pci-mt7621.c | 99 +++++++++++++++++++++++++++++++--
> >  1 file changed, 95 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/staging/mt7621-pci/pci-mt7621.c b/drivers/staging/mt7621-pci/pci-mt7621.c
> > index 4f56840..6187d41 100644
> > --- a/drivers/staging/mt7621-pci/pci-mt7621.c
> > +++ b/drivers/staging/mt7621-pci/pci-mt7621.c
> > @@ -52,6 +52,9 @@
> >  #include <linux/delay.h>
> >  #include <linux/of.h>
> >  #include <linux/of_pci.h>
> > +#include <linux/of_platform.h>
> > +#include <linux/of_address.h>
> > +#include <linux/of_irq.h>
> >  #include <linux/platform_device.h>
> >  
> >  #include <ralink_regs.h>
> > @@ -177,6 +180,32 @@ static int pcie_link_status = 0;
> >  #define PCI_ACCESS_WRITE_2 4
> >  #define PCI_ACCESS_WRITE_4 5
> >  
> > +/**
> > + * struct mt7621_pcie_port - PCIe port information
> > + * @base: IO mapped register base
> > + * @list: port list
> > + * @pcie: pointer to PCIe host info
> > + * @reset: pointer to port reset control
> > + */
> > +struct mt7621_pcie_port {
> > +	void __iomem *base;
> > +	struct list_head list;
> > +	struct mt7621_pcie *pcie;
> > +	struct reset_control *reset;
> > +};
> > +
> > +/**
> > + * struct mt7621_pcie - PCIe host information
> > + * @base: IO Mapped Register Base
> > + * @dev: Pointer to PCIe device
> > + * @ports: pointer to PCIe port information
> > + */
> > +struct mt7621_pcie {
> > +	void __iomem *base;
> > +	struct device *dev;
> > +	struct list_head ports;
> > +};
> > +
> >  static inline u32 mt7621_pci_get_cfgaddr(unsigned int bus, unsigned int slot,
> >  					 unsigned int func, unsigned int where)
> >  {
> > @@ -296,15 +325,27 @@ pci_config_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u
> >  	}
> >  }
> >  
> > +static void __iomem *mt7621_pcie_map_bus(struct pci_bus *bus,
> > +					 unsigned int devfn, int where)
> > +{
> > +	struct mt7621_pcie *pcie = bus->sysdata;
> > +	u32 address = mt7621_pci_get_cfgaddr(bus->number, PCI_SLOT(devfn),
> > +					     PCI_FUNC(devfn), where);
> > +
> > +	writel(address, pcie->base + RALINK_PCI_CONFIG_ADDR);
> > +
> > +	return pcie->base + RALINK_PCI_CONFIG_DATA_VIRTUAL_REG + (where & 3);
> > +}
> > +
> >  struct pci_ops mt7621_pci_ops = {
> > -	.read		= pci_config_read,
> > -	.write		= pci_config_write,
> > +	.map_bus	= mt7621_pcie_map_bus,
> > +	.read		= pci_generic_config_read,
> > +	.write		= pci_generic_config_write,
> >  };
> >  
> >  static struct resource mt7621_res_pci_mem1;
> >  static struct resource mt7621_res_pci_io1;
> >  static struct pci_controller mt7621_controller = {
> > -	.pci_ops	= &mt7621_pci_ops,
> >  	.mem_resource	= &mt7621_res_pci_mem1,
> >  	.io_resource	= &mt7621_res_pci_io1,
> >  };
> > @@ -479,10 +520,61 @@ void setup_cm_memory_region(struct resource *mem_resource)
> >  	}
> >  }
> >  
> > +static int mt7621_pcie_parse_dt(struct mt7621_pcie *pcie)
> > +{
> > +	struct device *dev = pcie->dev;
> > +	struct device_node *node = dev->of_node;
> > +	struct resource regs;
> > +	const char *type;
> > +	int err;
> > +
> > +	type = of_get_property(node, "device_type", NULL);
> > +	if (!type || strcmp(type, "pci") != 0) {
> > +		dev_err(dev, "invalid \"device_type\" %s\n", type);
> > +		return -EINVAL;
> > +	}
> > +
> > +	err = of_address_to_resource(node, 0, &regs);
> > +	if (err) {
> > +		dev_err(dev, "missing \"reg\" property\n");
> > +		return err;
> > +	}
> > +
> > +	pcie->base = devm_pci_remap_cfg_resource(dev, &regs);
> > +	if (IS_ERR(pcie->base))
> > +		return PTR_ERR(pcie->base);
> > +
> > +	return 0;
> > +}
> > +
> >  static int mt7621_pci_probe(struct platform_device *pdev)
> >  {
> > +	struct device *dev = &pdev->dev;
> > +	struct mt7621_pcie *pcie;
> > +	struct pci_host_bridge *bridge;
> > +	int err;
> >  	unsigned long val = 0;
> >  
> > +	bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie));
> > +	if (!bridge)
> > +		return -ENODEV;
> > +
> > +	pcie = pci_host_bridge_priv(bridge);
> > +	pcie->dev = dev;
> > +	INIT_LIST_HEAD(&pcie->ports);
> > +
> > +	err = mt7621_pcie_parse_dt(pcie);
> > +	if (err) {
> > +		dev_err(dev, "Parsing DT failed\n");
> 
> We need to free bridge on this error path.

I think is ok as it is. 'devm_pci_alloc_host_bridge' set internally
'devm_pci_release_host_bridge_dev' as 'bridge->dev.release'
callback to be called.

> 
> > +		return err;
> > +	}
> 
> regards,
> dan carpenter
> 

Best regards,
    Sergio Paracuellos