linux/drivers/mfd/cs5535-mfd.c
Lee Jones 2d4ba9173a mfd: cs5535-mfd: Request shared IO regions centrally
Prior to this patch, IO regions were requested via an MFD subsytem-level
.enable() call-back and similarly released by a .disable() call-back.
Double requests/releases were avoided by a centrally handled usage count
mechanism.

This complexity can all be avoided by handling IO regions only once during
.probe() and .remove() of the parent device.  Since this is the only
legitimate user of the aforementioned usage count mechanism, this patch
will allow it to be removed from MFD core in subsequent steps.

Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
2019-11-11 08:45:03 +00:00

157 lines
3.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* cs5535-mfd.c - core MFD driver for CS5535/CS5536 southbridges
*
* The CS5535 and CS5536 has an ISA bridge on the PCI bus that is
* used for accessing GPIOs, MFGPTs, ACPI, etc. Each subdevice has
* an IO range that's specified in a single BAR. The BAR order is
* hardcoded in the CS553x specifications.
*
* Copyright (c) 2010 Andres Salomon <dilinger@queued.net>
*/
#include <linux/kernel.h>
#include <linux/mfd/core.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <asm/olpc.h>
#define DRV_NAME "cs5535-mfd"
enum cs5535_mfd_bars {
SMB_BAR = 0,
GPIO_BAR = 1,
MFGPT_BAR = 2,
PMS_BAR = 4,
ACPI_BAR = 5,
NR_BARS,
};
static struct resource cs5535_mfd_resources[NR_BARS];
static struct mfd_cell cs5535_mfd_cells[] = {
{
.name = "cs5535-smb",
.num_resources = 1,
.resources = &cs5535_mfd_resources[SMB_BAR],
},
{
.name = "cs5535-gpio",
.num_resources = 1,
.resources = &cs5535_mfd_resources[GPIO_BAR],
},
{
.name = "cs5535-mfgpt",
.num_resources = 1,
.resources = &cs5535_mfd_resources[MFGPT_BAR],
},
{
.name = "cs5535-pms",
.num_resources = 1,
.resources = &cs5535_mfd_resources[PMS_BAR],
},
{
.name = "cs5535-acpi",
.num_resources = 1,
.resources = &cs5535_mfd_resources[ACPI_BAR],
},
};
static const char *olpc_acpi_clones[] = {
"olpc-xo1-pm-acpi",
"olpc-xo1-sci-acpi"
};
static int cs5535_mfd_probe(struct pci_dev *pdev,
const struct pci_device_id *id)
{
int err, bar;
err = pci_enable_device(pdev);
if (err)
return err;
for (bar = 0; bar < NR_BARS; bar++) {
struct resource *r = &cs5535_mfd_resources[bar];
r->flags = IORESOURCE_IO;
r->start = pci_resource_start(pdev, bar);
r->end = pci_resource_end(pdev, bar);
}
err = pci_request_region(pdev, PMS_BAR, DRV_NAME);
if (err) {
dev_err(&pdev->dev, "Failed to request PMS_BAR's IO region\n");
goto err_disable;
}
err = mfd_add_devices(&pdev->dev, PLATFORM_DEVID_NONE, cs5535_mfd_cells,
ARRAY_SIZE(cs5535_mfd_cells), NULL, 0, NULL);
if (err) {
dev_err(&pdev->dev,
"Failed to add CS5535 sub-devices: %d\n", err);
goto err_release_pms;
}
if (machine_is_olpc()) {
err = pci_request_region(pdev, ACPI_BAR, DRV_NAME);
if (err) {
dev_err(&pdev->dev,
"Failed to request ACPI_BAR's IO region\n");
goto err_remove_devices;
}
err = mfd_clone_cell("cs5535-acpi", olpc_acpi_clones,
ARRAY_SIZE(olpc_acpi_clones));
if (err) {
dev_err(&pdev->dev, "Failed to clone MFD cell\n");
goto err_release_acpi;
}
}
dev_info(&pdev->dev, "%zu devices registered.\n",
ARRAY_SIZE(cs5535_mfd_cells));
return 0;
err_release_acpi:
pci_release_region(pdev, ACPI_BAR);
err_remove_devices:
mfd_remove_devices(&pdev->dev);
err_release_pms:
pci_release_region(pdev, PMS_BAR);
err_disable:
pci_disable_device(pdev);
return err;
}
static void cs5535_mfd_remove(struct pci_dev *pdev)
{
mfd_remove_devices(&pdev->dev);
if (machine_is_olpc())
pci_release_region(pdev, ACPI_BAR);
pci_release_region(pdev, PMS_BAR);
pci_disable_device(pdev);
}
static const struct pci_device_id cs5535_mfd_pci_tbl[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_CS5535_ISA) },
{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA) },
{ 0, }
};
MODULE_DEVICE_TABLE(pci, cs5535_mfd_pci_tbl);
static struct pci_driver cs5535_mfd_driver = {
.name = DRV_NAME,
.id_table = cs5535_mfd_pci_tbl,
.probe = cs5535_mfd_probe,
.remove = cs5535_mfd_remove,
};
module_pci_driver(cs5535_mfd_driver);
MODULE_AUTHOR("Andres Salomon <dilinger@queued.net>");
MODULE_DESCRIPTION("MFD driver for CS5535/CS5536 southbridge's ISA PCI device");
MODULE_LICENSE("GPL");