Re: [PATCH v3 1/3] MFD: introduce lpc_sch for Intel SCH LPC bridge

From: Jean Delvare
Date: Tue Feb 23 2010 - 03:26:44 EST

On Thu, 18 Feb 2010 20:01:33 +0200, Denis Turischev wrote:
> Intel Poulsbo (SCH) chipset LPC bridge controller contains several
> functions. Creating and MFD driver for the LPC bridge controller allows
> simultaneous use of SMBus and GPIO interfaces on the SCH.
>
> v2: added "select MFD_CORE"
> v3: removed "default m"
>
> Signed-off-by: Denis Turischev <denis@xxxxxxxxxxxxxx>
>
> diff -Nru linux-2.6.33-rc7.orig/drivers/mfd/Kconfig linux-2.6.33-rc7/drivers/mfd/Kconfig
> --- linux-2.6.33-rc7.orig/drivers/mfd/Kconfig 2010-02-07 00:17:12.000000000 +0200
> +++ linux-2.6.33-rc7/drivers/mfd/Kconfig 2010-02-18 19:56:19.000000000 +0200
> @@ -348,6 +348,14 @@
> read/write functions for the devices to get access to this chip.
> This chip embeds various other multimedia funtionalities as well.
>
> +config LPC_SCH
> + tristate "Intel SCH LPC"
> + depends on PCI
> + select MFD_CORE
> + help
> + LPC bridge function of the Intel SCH provides support for
> + System Management Bus and General Purpose I/O.
> +
> endmenu
>
> menu "Multimedia Capabilities Port drivers"
> diff -Nru linux-2.6.33-rc7.orig/drivers/mfd/lpc_sch.c linux-2.6.33-rc7/drivers/mfd/lpc_sch.c
> --- linux-2.6.33-rc7.orig/drivers/mfd/lpc_sch.c 1970-01-01 02:00:00.000000000 +0200
> +++ linux-2.6.33-rc7/drivers/mfd/lpc_sch.c 2010-02-11 10:31:54.000000000 +0200
> @@ -0,0 +1,133 @@
> +/*
> + * lpc_sch.c - LPC interface for Intel Poulsbo SCH
> + *
> + * LPC bridge function of the Intel SCH contains many other
> + * functional units, such as Interrupt controllers, Timers,
> + * Power Management, System Management, GPIO, RTC, and LPC
> + * Configuration Registers.
> + *
> + * Copyright (c) 2010 CompuLab Ltd
> + * Author: Denis Turischev <denis@xxxxxxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License 2 as published
> + * by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; see the file COPYING. If not, write to
> + * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
> + */
> +
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/errno.h>
> +#include <linux/acpi.h>
> +#include <linux/pci.h>
> +#include <linux/mfd/core.h>
> +
> +#define SMBASE 0x40
> +#define SMBUS_IO_SIZE 64
> +
> +#define GPIOBASE 0x44
> +#define GPIO_IO_SIZE 64
> +
> +static struct resource smbus_sch_resource = {
> + .flags = IORESOURCE_IO,
> +};
> +
> +
> +static struct resource gpio_sch_resource = {
> + .flags = IORESOURCE_IO,
> +};
> +
> +static struct mfd_cell lpc_sch_cells[] = {
> + {
> + .name = "isch_smbus",
> + .num_resources = 1,
> + .resources = &smbus_sch_resource,
> + },
> + {
> + .name = "sch_gpio",
> + .num_resources = 1,
> + .resources = &gpio_sch_resource,
> + },
> +};

These names are nicely inconsistent. What about "isch_gpio"?

> +
> +static struct pci_device_id lpc_sch_ids[] = {
> + { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_SCH_LPC) },
> + { 0, }
> +};
> +MODULE_DEVICE_TABLE(pci, lpc_sch_ids);
> +
> +static int __devinit lpc_sch_probe(struct pci_dev *dev,
> + const struct pci_device_id *id)
> +{
> + unsigned int base_addr_cfg;
> + unsigned short base_addr;
> +
> + pci_read_config_dword(dev, SMBASE, &base_addr_cfg);
> + if (!(base_addr_cfg & (1 << 31))) {
> + dev_err(&dev->dev, "Decode of the SMBus I/O range disabled\n");
> + return -ENODEV;
> + }
> + base_addr = (unsigned short)base_addr_cfg;
> + if (base_addr == 0) {
> + dev_err(&dev->dev, "I/O space for SMBus uninitialized\n");
> + return -ENODEV;
> + }
> +
> + smbus_sch_resource.start = base_addr;
> + smbus_sch_resource.end = base_addr + SMBUS_IO_SIZE - 1;
> +
> + pci_read_config_dword(dev, GPIOBASE, &base_addr_cfg);
> + if (!(base_addr_cfg & (1 << 31))) {
> + dev_err(&dev->dev, "Decode of the GPIO I/O range disabled\n");
> + return -ENODEV;
> + }
> + base_addr = (unsigned short)base_addr_cfg;
> + if (base_addr == 0) {
> + dev_err(&dev->dev, "I/O space for GPIO uninitialized\n");
> + return -ENODEV;
> + }
> +
> + gpio_sch_resource.start = base_addr;
> + gpio_sch_resource.end = base_addr + GPIO_IO_SIZE - 1;
> +
> + return mfd_add_devices(&dev->dev, -1,
> + lpc_sch_cells, ARRAY_SIZE(lpc_sch_cells), NULL, 0);
> +}
> +
> +static void __devexit lpc_sch_remove(struct pci_dev *dev)
> +{
> + mfd_remove_devices(&dev->dev);
> +}
> +
> +static struct pci_driver lpc_sch_driver = {
> + .name = "lpc_sch",
> + .id_table = lpc_sch_ids,
> + .probe = lpc_sch_probe,
> + .remove = __devexit_p(lpc_sch_remove),
> +};
> +
> +static int __init lpc_sch_init(void)
> +{
> + return pci_register_driver(&lpc_sch_driver);
> +}
> +
> +static void __exit lpc_sch_exit(void)
> +{
> + pci_unregister_driver(&lpc_sch_driver);
> +}
> +
> +module_init(lpc_sch_init);
> +module_exit(lpc_sch_exit);
> +
> +MODULE_AUTHOR("Denis Turischev <denis@xxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("LPC interface for Intel Poulsbo SCH");
> +MODULE_LICENSE("GPL");
> diff -Nru linux-2.6.33-rc7.orig/drivers/mfd/Makefile linux-2.6.33-rc7/drivers/mfd/Makefile
> --- linux-2.6.33-rc7.orig/drivers/mfd/Makefile 2010-02-07 00:17:12.000000000 +0200
> +++ linux-2.6.33-rc7/drivers/mfd/Makefile 2010-02-10 15:15:40.000000000 +0200
> @@ -55,4 +55,5 @@
> obj-$(CONFIG_AB3100_OTP) += ab3100-otp.o
> obj-$(CONFIG_AB4500_CORE) += ab4500-core.o
> obj-$(CONFIG_MFD_88PM8607) += 88pm8607.o
> -obj-$(CONFIG_PMIC_ADP5520) += adp5520.o
> \ No newline at end of file
> +obj-$(CONFIG_PMIC_ADP5520) += adp5520.o
> +obj-$(CONFIG_LPC_SCH) += lpc_sch.o

I don't like this name either. There is another vendor (SMSC) shipping
LPC devices with "SCH" in their names, so there is room for confusion.
"isch" makes it clearer that we are talking about the Intel ones.

--
Jean Delvare
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