Re: [PATCH] mmc: Disabler for Ricoh MMC controller

[Benjamin Herrenschmidt]

On Tue, 2007-10-02 at 14:44 +1000, Benjamin Herrenschmidt wrote:
> On Mon, 2007-10-01 at 20:23 -0700, Philip Langdale wrote:
> > Thanks to Matt Domsch and Rezwanul Kabir at Dell, we know how to disable the
> > MMC controller on the multi-function Ricoh R5C832. The MMC controller needs
> > to be disabled or it will steal MMC cards from the SD controller where they
> > would otherwise be supported by the Linux SDHCI driver.
> 
> Why can't that be a quirk instead ?

That is, a global quirk or a quirk in the SDHCI driver...

> > Signed-off-by: Philipl Langdale <philipl@xxxxxxxxx>
> > 
> > --- linux-2.6.22/drivers/mmc/host/Kconfig	2007-07-08 16:32:17.000000000 -0700
> > +++ linux-ricoh/drivers/mmc/host/Kconfig	2007-09-15 12:32:10.000000000 -0700
> > @@ -35,6 +35,23 @@
> > 
> >  	  If unsure, say N.
> > 
> > +config MMC_RICOH_MMC
> > +	tristate "Ricoh MMC Controller Disabler  (EXPERIMENTAL)"
> > +	depends on PCI && EXPERIMENTAL && MMC_SDHCI
> > +	help
> > +	  This selects the disabler for the Ricoh MMC Controller. This
> > +	  proprietary controller is unnecessary because the SDHCI driver
> > +	  supports MMC cards on the SD controller, but if it is not
> > +	  disabled, it will steal the MMC cards away - rendering them
> > +	  useless. It is safe to select this driver even if you don't
> > +	  have a Ricoh based card reader.
> > +
> > +
> > +	  To compile this driver as a module, choose M here:
> > +	  the module will be called ricoh_mmc.
> > +
> > +	  If unsure, say Y.
> > +
> >  config MMC_OMAP
> >  	tristate "TI OMAP Multimedia Card Interface support"
> >  	depends on ARCH_OMAP
> > --- linux-2.6.22/drivers/mmc/host/Makefile	2007-07-08 16:32:17.000000000 -0700
> > +++ linux-ricoh/drivers/mmc/host/Makefile	2007-09-15 12:28:49.000000000 -0700
> > @@ -15,4 +15,5 @@
> >  obj-$(CONFIG_MMC_OMAP)		+= omap.o
> >  obj-$(CONFIG_MMC_AT91)		+= at91_mci.o
> >  obj-$(CONFIG_MMC_TIFM_SD)	+= tifm_sd.o
> > +obj-$(CONFIG_MMC_RICOH_MMC)	+= ricoh_mmc.o
> > 
> > --- linux-2.6.22/drivers/mmc/host/ricoh_mmc.c	1969-12-31 16:00:00.000000000 -0800
> > +++ linux-ricoh/drivers/mmc/host/ricoh_mmc.c	2007-09-15 12:29:05.000000000 -0700
> > @@ -0,0 +1,156 @@
> > +/*
> > + *  ricoh_mmc.c - Dummy driver to disable the Rioch MMC controller.
> > + *
> > + *  Copyright (C) 2007 Philip Langdale, All Rights Reserved.
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License as published by
> > + * the Free Software Foundation; either version 2 of the License, or (at
> > + * your option) any later version.
> > + */
> > +
> > +/*
> > + * This is a conceptually ridiculous driver, but it is required by the way
> > + * the Ricoh multi-function R5C832 works. This chip implements firewire
> > + * and four different memory card controllers. Two of those controllers are
> > + * an SDHCI controller and a proprietary MMC controller. The linux SDHCI
> > + * driver supports MMC cards but the chip detects MMC cards in hardware
> > + * and directs them to the MMC controller - so the SDHCI driver never sees
> > + * them. To get around this, we must disable the useless MMC controller.
> > + * At that point, the SDHCI controller will start seeing them. As a bonus,
> > + * a detection event occurs immediately, even if the MMC card is already
> > + * in the reader.
> > + *
> > + * The relevant registers live on the firewire function, so this is unavoidably
> > + * ugly. Such is life.
> > + */
> > +
> > +#include <linux/pci.h>
> > +
> > +#define DRIVER_NAME "ricoh-mmc"
> > +
> > +#define DBG(f, x...) \
> > +	pr_debug(DRIVER_NAME " [%s()]: " f, __func__,## x)
> > +
> > +static const struct pci_device_id pci_ids[] __devinitdata = {
> > +	{
> > +		.vendor		= PCI_VENDOR_ID_RICOH,
> > +		.device		= PCI_DEVICE_ID_RICOH_R5C843,
> > +		.subvendor	= PCI_ANY_ID,
> > +		.subdevice	= PCI_ANY_ID,
> > +	},
> > +	{ /* end: all zeroes */ },
> > +};
> > +
> > +MODULE_DEVICE_TABLE(pci, pci_ids);
> > +
> > +static int __devinit ricoh_mmc_probe(struct pci_dev *pdev,
> > +				     const struct pci_device_id *ent)
> > +{
> > +	u8 rev;
> > +
> > +	struct pci_dev *fw_dev = NULL;
> > +
> > +	BUG_ON(pdev == NULL);
> > +	BUG_ON(ent == NULL);
> > +
> > +	pci_read_config_byte(pdev, PCI_CLASS_REVISION, &rev);
> > +
> > +	printk(KERN_INFO DRIVER_NAME
> > +		": Ricoh MMC controller found at %s [%04x:%04x] (rev %x)\n",
> > +		pci_name(pdev), (int)pdev->vendor, (int)pdev->device,
> > +		(int)rev);
> > +
> > +	while ((fw_dev = pci_get_device(PCI_VENDOR_ID_RICOH, PCI_DEVICE_ID_RICOH_R5C832, fw_dev))) {
> > +		if (PCI_SLOT(pdev->devfn) == PCI_SLOT(fw_dev->devfn) &&
> > +		    pdev->bus == fw_dev->bus) {
> > +			u8 write_enable;
> > +			u8 disable;
> > +
> > +			pci_read_config_byte(fw_dev, 0xCB, &disable);
> > +			if (disable & 0x02) {
> > +				printk(KERN_INFO DRIVER_NAME
> > +				       ": Controller already disabled. Nothing to do.\n");
> > +				return -ENODEV;
> > +			}
> > +
> > +			pci_read_config_byte(fw_dev, 0xCA, &write_enable);
> > +			pci_write_config_byte(fw_dev, 0xCA, 0x57);
> > +			pci_write_config_byte(fw_dev, 0xCB, disable | 0x02);
> > +			pci_write_config_byte(fw_dev, 0xCA, write_enable);
> > +
> > +			pci_set_drvdata(pdev, fw_dev);
> > +
> > +			printk(KERN_INFO DRIVER_NAME
> > +			       ": Controller is now disabled.\n");
> > +
> > +			break;
> > +		}
> > +	}
> > +
> > +	if (pci_get_drvdata(pdev) == NULL) {
> > +		printk(KERN_WARNING DRIVER_NAME
> > +		       ": Main firewire function not found. Cannot disable controller.\n");
> > +		return -ENODEV;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static void __devexit ricoh_mmc_remove(struct pci_dev *pdev)
> > +{
> > +	u8 write_enable;
> > +	u8 disable;
> > +	struct pci_dev *fw_dev = NULL;
> > +
> > +	fw_dev = pci_get_drvdata(pdev);
> > +	BUG_ON(fw_dev == NULL);
> > +
> > +	pci_read_config_byte(fw_dev, 0xCA, &write_enable);
> > +	pci_read_config_byte(fw_dev, 0xCB, &disable);
> > +	pci_write_config_byte(fw_dev, 0xCA, 0x57);
> > +	pci_write_config_byte(fw_dev, 0xCB, disable & ~0x02);
> > +	pci_write_config_byte(fw_dev, 0xCA, write_enable);
> > +
> > +	printk(KERN_INFO DRIVER_NAME
> > +	       ": Controller is now re-enabled.\n");
> > +
> > +	pci_set_drvdata(pdev, NULL);
> > +}
> > +
> > +static struct pci_driver ricoh_mmc_driver = {
> > +	.name = 	DRIVER_NAME,
> > +	.id_table =	pci_ids,
> > +	.probe = 	ricoh_mmc_probe,
> > +	.remove =	__devexit_p(ricoh_mmc_remove),
> > +};
> > +
> > +/*****************************************************************************\
> > + *                                                                           *
> > + * Driver init/exit                                                          *
> > + *                                                                           *
> > +\*****************************************************************************/
> > +
> > +static int __init ricoh_mmc_drv_init(void)
> > +{
> > +	printk(KERN_INFO DRIVER_NAME
> > +		": Ricoh MMC Controller disabling driver\n");
> > +	printk(KERN_INFO DRIVER_NAME ": Copyright(c) Philip Langdale\n");
> > +
> > +	return pci_register_driver(&ricoh_mmc_driver);
> > +}
> > +
> > +static void __exit ricoh_mmc_drv_exit(void)
> > +{
> > +	DBG("Exiting\n");
> > +
> > +	pci_unregister_driver(&ricoh_mmc_driver);
> > +}
> > +
> > +module_init(ricoh_mmc_drv_init);
> > +module_exit(ricoh_mmc_drv_exit);
> > +
> > +MODULE_AUTHOR("Philip Langdale <philipl@xxxxxxxxxxxxxxxxx>");
> > +MODULE_DESCRIPTION("Ricoh MMC Controller disabling driver");
> > +MODULE_LICENSE("GPL");
> > +
> > --- linux-2.6.22/include/linux/pci_ids.h	2007-09-02 00:14:25.000000000 -0700
> > +++ linux-ricoh/include/linux/pci_ids.h	2007-09-15 12:27:36.000000000 -0700
> > @@ -1485,6 +1485,8 @@
> >  #define PCI_DEVICE_ID_RICOH_RL5C476	0x0476
> >  #define PCI_DEVICE_ID_RICOH_RL5C478	0x0478
> >  #define PCI_DEVICE_ID_RICOH_R5C822	0x0822
> > +#define PCI_DEVICE_ID_RICOH_R5C832	0x0832
> > +#define PCI_DEVICE_ID_RICOH_R5C843	0x0843
> > 
> >  #define PCI_VENDOR_ID_DLINK		0x1186
> >  #define PCI_DEVICE_ID_DLINK_DGE510T	0x4c00
> > -
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