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i2c: Convert SCx200 driver from using raw PCI to platform device
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The SCx200 ACB driver supports ISA hardware as well as PCI.  The PCI
hardware is CS5535/CS5536 based, and the device that it grabs is handled by
the cs5535-mfd driver. This converts the SCx200 driver to use a
platform_driver rather than the previous PCI hackery.

The driver used to manually track the iface list (via linked list); now it
only does this for ISA devices.  PCI ifaces are handled through standard
driver model lists.

It's unclear what happens in case of errors in the old ISA code; rather than
pretending the code actually cares, I've dropped the (implicit) ignorance
of return values and marked it with a comment.

Signed-off-by: Andres Salomon <dilinger@queued.net>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
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Andres Salomon authored and Samuel Ortiz committed Jan 14, 2011
1 parent 419cdc5 commit de8255c
Showing 1 changed file with 80 additions and 120 deletions.
200 changes: 80 additions & 120 deletions drivers/i2c/busses/scx200_acb.c
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Original file line number Diff line number Diff line change
Expand Up @@ -29,6 +29,7 @@
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/mutex.h>
#include <linux/slab.h>
Expand All @@ -40,6 +41,7 @@

MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
MODULE_DESCRIPTION("NatSemi SCx200 ACCESS.bus Driver");
MODULE_ALIAS("platform:cs5535-smb");
MODULE_LICENSE("GPL");

#define MAX_DEVICES 4
Expand Down Expand Up @@ -84,10 +86,6 @@ struct scx200_acb_iface {
u8 *ptr;
char needs_reset;
unsigned len;

/* PCI device info */
struct pci_dev *pdev;
int bar;
};

/* Register Definitions */
Expand Down Expand Up @@ -391,7 +389,7 @@ static const struct i2c_algorithm scx200_acb_algorithm = {
static struct scx200_acb_iface *scx200_acb_list;
static DEFINE_MUTEX(scx200_acb_list_mutex);

static __init int scx200_acb_probe(struct scx200_acb_iface *iface)
static __devinit int scx200_acb_probe(struct scx200_acb_iface *iface)
{
u8 val;

Expand Down Expand Up @@ -427,7 +425,7 @@ static __init int scx200_acb_probe(struct scx200_acb_iface *iface)
return 0;
}

static __init struct scx200_acb_iface *scx200_create_iface(const char *text,
static __devinit struct scx200_acb_iface *scx200_create_iface(const char *text,
struct device *dev, int index)
{
struct scx200_acb_iface *iface;
Expand All @@ -452,7 +450,7 @@ static __init struct scx200_acb_iface *scx200_create_iface(const char *text,
return iface;
}

static int __init scx200_acb_create(struct scx200_acb_iface *iface)
static int __devinit scx200_acb_create(struct scx200_acb_iface *iface)
{
struct i2c_adapter *adapter;
int rc;
Expand All @@ -472,183 +470,145 @@ static int __init scx200_acb_create(struct scx200_acb_iface *iface)
return -ENODEV;
}

mutex_lock(&scx200_acb_list_mutex);
iface->next = scx200_acb_list;
scx200_acb_list = iface;
mutex_unlock(&scx200_acb_list_mutex);
if (!adapter->dev.parent) {
/* If there's no dev, we're tracking (ISA) ifaces manually */
mutex_lock(&scx200_acb_list_mutex);
iface->next = scx200_acb_list;
scx200_acb_list = iface;
mutex_unlock(&scx200_acb_list_mutex);
}

return 0;
}

static __init int scx200_create_pci(const char *text, struct pci_dev *pdev,
int bar)
static struct scx200_acb_iface * __devinit scx200_create_dev(const char *text,
unsigned long base, int index, struct device *dev)
{
struct scx200_acb_iface *iface;
int rc;

iface = scx200_create_iface(text, &pdev->dev, 0);
iface = scx200_create_iface(text, dev, index);

if (iface == NULL)
return -ENOMEM;

iface->pdev = pdev;
iface->bar = bar;

rc = pci_enable_device_io(iface->pdev);
if (rc)
goto errout_free;
return NULL;

rc = pci_request_region(iface->pdev, iface->bar, iface->adapter.name);
if (rc) {
printk(KERN_ERR NAME ": can't allocate PCI BAR %d\n",
iface->bar);
if (!request_region(base, 8, iface->adapter.name)) {
printk(KERN_ERR NAME ": can't allocate io 0x%lx-0x%lx\n",
base, base + 8 - 1);
goto errout_free;
}

iface->base = pci_resource_start(iface->pdev, iface->bar);
iface->base = base;
rc = scx200_acb_create(iface);

if (rc == 0)
return 0;
return iface;

pci_release_region(iface->pdev, iface->bar);
pci_dev_put(iface->pdev);
release_region(base, 8);
errout_free:
kfree(iface);
return rc;
return NULL;
}

static int __init scx200_create_isa(const char *text, unsigned long base,
int index)
static int __devinit scx200_probe(struct platform_device *pdev)
{
struct scx200_acb_iface *iface;
int rc;

iface = scx200_create_iface(text, NULL, index);

if (iface == NULL)
return -ENOMEM;
struct resource *res;

if (!request_region(base, 8, iface->adapter.name)) {
printk(KERN_ERR NAME ": can't allocate io 0x%lx-0x%lx\n",
base, base + 8 - 1);
rc = -EBUSY;
goto errout_free;
res = platform_get_resource(pdev, IORESOURCE_IO, 0);
if (!res) {
dev_err(&pdev->dev, "can't fetch device resource info\n");
return -ENODEV;
}

iface->base = base;
rc = scx200_acb_create(iface);
iface = scx200_create_dev("CS5535", res->start, 0, &pdev->dev);
if (!iface)
return -EIO;

if (rc == 0)
return 0;
dev_info(&pdev->dev, "SCx200 device '%s' registered\n",
iface->adapter.name);
platform_set_drvdata(pdev, iface);

release_region(base, 8);
errout_free:
kfree(iface);
return rc;
return 0;
}

/* Driver data is an index into the scx200_data array that indicates
* the name and the BAR where the I/O address resource is located. ISA
* devices are flagged with a bar value of -1 */

static const struct pci_device_id scx200_pci[] __initconst = {
{ PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SCx200_BRIDGE),
.driver_data = 0 },
{ PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SC1100_BRIDGE),
.driver_data = 0 },
{ PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_CS5535_ISA),
.driver_data = 1 },
{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA),
.driver_data = 2 },
{ 0, }
};

static struct {
const char *name;
int bar;
} scx200_data[] = {
{ "SCx200", -1 },
{ "CS5535", 0 },
{ "CS5536", 0 }
};
static void __devexit scx200_cleanup_iface(struct scx200_acb_iface *iface)
{
i2c_del_adapter(&iface->adapter);
release_region(iface->base, 8);
kfree(iface);
}

static __init int scx200_scan_pci(void)
static int __devexit scx200_remove(struct platform_device *pdev)
{
int data, dev;
int rc = -ENODEV;
struct pci_dev *pdev;
struct scx200_acb_iface *iface;

for(dev = 0; dev < ARRAY_SIZE(scx200_pci); dev++) {
pdev = pci_get_device(scx200_pci[dev].vendor,
scx200_pci[dev].device, NULL);
iface = platform_get_drvdata(pdev);
platform_set_drvdata(pdev, NULL);
scx200_cleanup_iface(iface);

if (pdev == NULL)
continue;
return 0;
}

data = scx200_pci[dev].driver_data;
static struct platform_driver scx200_pci_drv = {
.driver = {
.name = "cs5535-smb",
.owner = THIS_MODULE,
},
.probe = scx200_probe,
.remove = __devexit_p(scx200_remove),
};

/* if .bar is greater or equal to zero, this is a
* PCI device - otherwise, we assume
that the ports are ISA based
*/
static const struct pci_device_id scx200_isa[] __initconst = {
{ PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SCx200_BRIDGE) },
{ PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SC1100_BRIDGE) },
{ 0, }
};

if (scx200_data[data].bar >= 0)
rc = scx200_create_pci(scx200_data[data].name, pdev,
scx200_data[data].bar);
else {
int i;
static __init void scx200_scan_isa(void)
{
int i;

pci_dev_put(pdev);
for (i = 0; i < MAX_DEVICES; ++i) {
if (base[i] == 0)
continue;
if (!pci_dev_present(scx200_isa))
return;

rc = scx200_create_isa(scx200_data[data].name,
base[i],
i);
}
}
for (i = 0; i < MAX_DEVICES; ++i) {
if (base[i] == 0)
continue;

break;
/* XXX: should we care about failures? */
scx200_create_dev("SCx200", base[i], i, NULL);
}

return rc;
}

static int __init scx200_acb_init(void)
{
int rc;

pr_debug(NAME ": NatSemi SCx200 ACCESS.bus Driver\n");

rc = scx200_scan_pci();
/* First scan for ISA-based devices */
scx200_scan_isa(); /* XXX: should we care about errors? */

/* If at least one bus was created, init must succeed */
if (scx200_acb_list)
return 0;
return rc;

/* No ISA devices; register the platform driver for PCI-based devices */
return platform_driver_register(&scx200_pci_drv);
}

static void __exit scx200_acb_cleanup(void)
{
struct scx200_acb_iface *iface;

platform_driver_unregister(&scx200_pci_drv);

mutex_lock(&scx200_acb_list_mutex);
while ((iface = scx200_acb_list) != NULL) {
scx200_acb_list = iface->next;
mutex_unlock(&scx200_acb_list_mutex);

i2c_del_adapter(&iface->adapter);

if (iface->pdev) {
pci_release_region(iface->pdev, iface->bar);
pci_dev_put(iface->pdev);
}
else
release_region(iface->base, 8);
scx200_cleanup_iface(iface);

kfree(iface);
mutex_lock(&scx200_acb_list_mutex);
}
mutex_unlock(&scx200_acb_list_mutex);
Expand Down

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