Messages in this thread | | | Date | Fri, 19 Mar 2010 11:22:09 -0700 | From | "Ira W. Snyder" <> | Subject | Re: [PATCH 1/3] mfd: add support for Janz CMOD-IO PCI MODULbus Carrier Board |
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On Fri, Mar 19, 2010 at 05:38:51PM +0100, Samuel Ortiz wrote: > Hi Ira, > > Some comments below: > > On Thu, Mar 18, 2010 at 09:38:42AM -0700, Ira W. Snyder wrote: > > +/* Module Parameters */ > > +static unsigned int num_modules = CMODIO_MAX_MODULES; > > +static unsigned char *modules[CMODIO_MAX_MODULES] = { > > + "janz-ican3", > > + "janz-ican3", > > + "", > > + "janz-ttl", > > +}; > That's not very nice, but I honestly dont know how to make it less ugly... > At least this should be all left blank by default, as Wolfgang hinted. >
Agreed, I've made the change in my tree.
> > +/* > > + * Subdevice Support > > + */ > Please use the mfd-core API for building and registering platform sub devices. > The pieces of code below should shrink significantly. >
Using this framework, how is it possible to create the devices that I do down below. For each subdevice, I need three resources:
1) MODULbus registers -- PCI BAR3 + (0x200 * module_num) 2) PLX Control Registers -- PCI BAR4 3) IRQ
Specifically, the way IORESOURCE_MEM resources are copied seems wrong. They start at the base address of only one resource and use the offsets provided in the struct mfd_cell. See the if-statement at drivers/mfd/mfd-core.c line 48.
I need two use two different parent resources. The mfd_add_devices() function doesn't support this.
> > +static int cmodio_remove_subdev(struct device *dev, void *data) > > +{ > > + platform_device_unregister(to_platform_device(dev)); > > + return 0; > > +} > > + > > +static void cmodio_subdev_release(struct device *dev) > > +{ > > + kfree(to_platform_device(dev)); > > +} > > + > > +static struct platform_device *cmodio_create_subdev(struct cmodio_device *priv, > > + char *name, > > + unsigned int res_count, > > + unsigned int pdata_size) > > +{ > > + struct platform_device *pdev; > > + size_t res_size; > > + > > + res_size = sizeof(struct resource) * res_count; > > + pdev = kzalloc(sizeof(*pdev) + res_size + pdata_size, GFP_KERNEL); > > + if (!pdev) > > + return NULL; > > + > > + pdev->dev.release = cmodio_subdev_release; > > + pdev->dev.parent = &priv->pdev->dev; > > + pdev->name = name; > > + > > + if (res_count) { > > + pdev->resource = (struct resource *)(pdev + 1); > > + pdev->num_resources = res_count; > > + } > > + > > + if (pdata_size) > > + pdev->dev.platform_data = (void *)(pdev + 1) + res_size; > > + > > + return pdev; > > +} > > + > > +/* Create a memory resource for a subdevice */ > > +static void cmodio_create_mem(struct resource *parent, struct resource *res, > > + resource_size_t offset, resource_size_t size) > > +{ > > + res->flags = IORESOURCE_MEM; > > + res->parent = parent; > > + res->start = parent->start + offset; > > + res->end = parent->start + offset + size - 1; > > +} > > + > > +/* Create an IRQ resource for a subdevice */ > > +static void cmodio_create_irq(struct resource *res, unsigned int irq) > > +{ > > + res->flags = IORESOURCE_IRQ; > > + res->parent = NULL; > > + res->start = irq; > > + res->end = irq; > > +} > > + > > +static int __devinit cmodio_probe_subdevice(struct cmodio_device *priv, > > + char *name, unsigned int modno) > > +{ > > + struct janz_platform_data *pdata; > > + struct platform_device *pdev; > > + resource_size_t offset, size; > > + struct pci_dev *pci; > > + int ret; > > + > > + pci = priv->pdev; > > + pdev = cmodio_create_subdev(priv, name, 3, sizeof(*pdata)); > > + if (!pdev) { > > + dev_err(&pci->dev, "MODULbus slot %d alloc failed\n", modno); > > + ret = -ENOMEM; > > + goto out_return; > > + } > > + > > + pdata = pdev->dev.platform_data; > > + pdata->modno = modno; > > + pdev->id = priv->subdev_id++; > > + > > + /* MODULbus registers -- PCI BAR3 is big-endian MODULbus access */ > > + offset = CMODIO_MODULBUS_SIZE * modno; > > + size = CMODIO_MODULBUS_SIZE; > > + cmodio_create_mem(&pci->resource[3], &pdev->resource[0], offset, size); > > + > > + /* PLX Control Registers -- PCI BAR4 is interrupt and other registers */ > > + offset = 0; > > + size = resource_size(&pci->resource[4]); > > + cmodio_create_mem(&pci->resource[4], &pdev->resource[1], offset, size); > > + > > + /* IRQ */ > > + cmodio_create_irq(&pdev->resource[2], pci->irq); > > + > > + /* Register the device */ > > + ret = platform_device_register(pdev); > > + if (ret) { > > + dev_err(&pci->dev, "MODULbus slot %d register failed\n", modno); > > + goto out_free; > > + } > > + > > + return 0; > > + > > +out_free: > > + cmodio_subdev_release(&pdev->dev); > > +out_return: > > + return ret; > > +} > > + > > +/* Probe each submodule using kernel parameters */ > > +static int __devinit cmodio_probe_submodules(struct cmodio_device *priv) > > +{ > > + char *name; > > + int i; > > + > > + for (i = 0; i < num_modules; i++) { > > + name = modules[i]; > > + if (!strcmp(name, "")) > > + continue; > > + > > + dev_dbg(&priv->pdev->dev, "MODULbus %d: name %s\n", i, name); > > + cmodio_probe_subdevice(priv, name, i); > > + } > > + > > + return 0; > > +} > > > > +/* > > + * PCI Driver > > + */ > > + > > +static int __devinit cmodio_pci_probe(struct pci_dev *dev, > > + const struct pci_device_id *id) > > +{ > > + struct cmodio_device *priv; > > + int ret; > > + > > + priv = kzalloc(sizeof(*priv), GFP_KERNEL); > > + if (!priv) { > > + dev_err(&dev->dev, "unable to allocate private data\n"); > > + ret = -ENOMEM; > > + goto out_return; > > + } > > + > > + pci_set_drvdata(dev, priv); > > + priv->pdev = dev; > > + > > + /* Hardware Initialization */ > > + ret = pci_enable_device(dev); > > + if (ret) { > > + dev_err(&dev->dev, "unable to enable device\n"); > > + goto out_free_priv; > > + } > > + > > + pci_set_master(dev); > > + ret = pci_request_regions(dev, DRV_NAME); > > + if (ret) { > > + dev_err(&dev->dev, "unable to request regions\n"); > > + goto out_pci_disable_device; > > + } > > + > > + /* Onboard configuration registers */ > > + priv->ctrl = pci_ioremap_bar(dev, 4); > Why 4 ? > >
Because that is how the device works ;) There is a comment up above that describes them as the "PLX control registers". Are you suggesting that I add a comment here too?
I think lots of other PCI devices just use hard-coded numbers here. They're device specific. You won't be able to program for the device at all if you don't know the meaning of each PCI BAR.
> > +#define PCI_VENDOR_ID_JANZ 0x13c3 > That probably belongs to pci_ids.h >
Should I add a patch to the series for this?
Thanks, Ira
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