Date:	Fri, 29 Jan 2010 08:06:39 -0800
From:	Philip Langdale <philipl@...rt.org>
To:	Maxim Levitsky <maximlevitsky@...il.com>
Cc:	Wolfram Sang <w.sang@...gutronix.de>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Pierre Ossman <pierre@...man.eu>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	linux-mmc@...r.kernel.org
Subject: Re: [PATCH v3] port ricoh_mmc to pci quirk

On Fri, 29 Jan 2010 15:37:35 +0200
Maxim Levitsky <maximlevitsky@...il.com> wrote:

> Here, updated patch with your comments addressed.
> This is also tested with real MMC card.

Actual code gets my thumbs up.

> This adds some > 80 chars lines, but I hope that is ok.

It's against the coding style and as far as I can see, the only
lines that are > 80 are the dev_notice and DECLARE_FIXUP lines - both
of which can be trivially split across multiple lines, so please just
do that.

Thanks,

--phil

> ---
> 
> >From 9b208770b2421eae50e46d826f08a4084c2bcdb9 Mon Sep 17 00:00:00
> >2001
> From: Maxim Levitsky <maximlevitsky@...il.com>
> Date: Fri, 29 Jan 2010 15:30:46 +0200
> Subject: [PATCH] Port ricoh_mmc to pci quirk
> 
> This patch solves nasty problem original driver had.
> Original goal of the ricoh_mmc, was to disable this device because
> then, mmc cards can be read using standard SDHCI controller,
> thus avoiding the need in yet another driver.
> However, the act of disablement, makes other pci functions that
> belong to this controller (xD and memstick) shift up one level, thus
> pci core has now wrong idea about these devices.
> 
> To fix this issue, this patch moves the driver into pci quirk
> section, thus it is executed before the pci is enumerated, and
> therefore solve that issue, also the same is preformed on resume for
> same reasons.
> 
> Also regardless of the above, this way is cleaner.
> 
> You still need to set CONFIG_MMC_RICOH_MMC
> to enable this quirk
> 
> Signed-off-by: Maxim Levitsky <maximlevitsky@...il.com>
> ---
>  drivers/mmc/host/Kconfig     |   10 +-
>  drivers/mmc/host/Makefile    |    1 -
>  drivers/mmc/host/ricoh_mmc.c |  262
> ------------------------------------------
> drivers/pci/quirks.c         |   82 +++++++++++++ 4 files changed, 85
> insertions(+), 270 deletions(-) delete mode 100644
> drivers/mmc/host/ricoh_mmc.c
> 
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index ce1d288..6bc3ecb 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -69,20 +69,16 @@ config MMC_SDHCI_PCI
>  	  If unsure, say N.
>  
>  config MMC_RICOH_MMC
> -	tristate "Ricoh MMC Controller Disabler  (EXPERIMENTAL)"
> +	bool "Ricoh MMC Controller Disabler  (EXPERIMENTAL)"
>  	depends on MMC_SDHCI_PCI
>  	help
> -	  This selects the disabler for the Ricoh MMC Controller.
> This
> +	  This adds a pci quirk to disable 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
> +	  useless. It is safe to select this 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_SDHCI_OF
> diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
> index 3d253dd..f480397 100644
> --- a/drivers/mmc/host/Makefile
> +++ b/drivers/mmc/host/Makefile
> @@ -12,7 +12,6 @@ obj-$(CONFIG_MMC_IMX)		+= imxmmc.o
>  obj-$(CONFIG_MMC_MXC)		+= mxcmmc.o
>  obj-$(CONFIG_MMC_SDHCI)		+= sdhci.o
>  obj-$(CONFIG_MMC_SDHCI_PCI)	+= sdhci-pci.o
> -obj-$(CONFIG_MMC_RICOH_MMC)	+= ricoh_mmc.o
>  obj-$(CONFIG_MMC_SDHCI_PLTFM)	+= sdhci-pltfm.o
>  obj-$(CONFIG_MMC_SDHCI_S3C)	+= sdhci-s3c.o
>  obj-$(CONFIG_MMC_WBSD)		+= wbsd.o
> diff --git a/drivers/mmc/host/ricoh_mmc.c
> b/drivers/mmc/host/ricoh_mmc.c deleted file mode 100644
> index f627905..0000000
> --- a/drivers/mmc/host/ricoh_mmc.c
> +++ /dev/null
> @@ -1,262 +0,0 @@
> -/*
> - *  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 chips (R5CXXX) work. These chips
> implement
> - * the four main memory card controllers (SD, MMC, MS, xD) and one
> or both
> - * of cardbus or firewire. It happens that they implement SD and MMC
> - * support as separate controllers (and PCI functions). 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.
> - *
> - * It seems to be the case that the relevant PCI registers to
> deactivate the
> - * MMC controller live on PCI function 0, which might be the cardbus
> controller
> - * or the firewire controller, depending on the particular chip in
> question. As
> - * such, it makes what this driver has to do unavoidably ugly. Such
> is life.
> - */
> -
> -#include <linux/pci.h>
> -
> -#define DRIVER_NAME "ricoh-mmc"
> -
> -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 ricoh_mmc_disable(struct pci_dev *fw_dev)
> -{
> -	u8 write_enable;
> -	u8 write_target;
> -	u8 disable;
> -
> -	if (fw_dev->device == PCI_DEVICE_ID_RICOH_RL5C476) {
> -		/* via RL5C476 */
> -
> -		pci_read_config_byte(fw_dev, 0xB7, &disable);
> -		if (disable & 0x02) {
> -			printk(KERN_INFO DRIVER_NAME
> -				": Controller already disabled. " \
> -				"Nothing to do.\n");
> -			return -ENODEV;
> -		}
> -
> -		pci_read_config_byte(fw_dev, 0x8E, &write_enable);
> -		pci_write_config_byte(fw_dev, 0x8E, 0xAA);
> -		pci_read_config_byte(fw_dev, 0x8D, &write_target);
> -		pci_write_config_byte(fw_dev, 0x8D, 0xB7);
> -		pci_write_config_byte(fw_dev, 0xB7, disable | 0x02);
> -		pci_write_config_byte(fw_dev, 0x8E, write_enable);
> -		pci_write_config_byte(fw_dev, 0x8D, write_target);
> -	} else {
> -		/* via R5C832 */
> -
> -		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);
> -	}
> -
> -	printk(KERN_INFO DRIVER_NAME
> -	       ": Controller is now disabled.\n");
> -
> -	return 0;
> -}
> -
> -static int ricoh_mmc_enable(struct pci_dev *fw_dev)
> -{
> -	u8 write_enable;
> -	u8 write_target;
> -	u8 disable;
> -
> -	if (fw_dev->device == PCI_DEVICE_ID_RICOH_RL5C476) {
> -		/* via RL5C476 */
> -
> -		pci_read_config_byte(fw_dev, 0x8E, &write_enable);
> -		pci_write_config_byte(fw_dev, 0x8E, 0xAA);
> -		pci_read_config_byte(fw_dev, 0x8D, &write_target);
> -		pci_write_config_byte(fw_dev, 0x8D, 0xB7);
> -		pci_read_config_byte(fw_dev, 0xB7, &disable);
> -		pci_write_config_byte(fw_dev, 0xB7, disable & ~0x02);
> -		pci_write_config_byte(fw_dev, 0x8E, write_enable);
> -		pci_write_config_byte(fw_dev, 0x8D, write_target);
> -	} else {
> -		/* via R5C832 */
> -
> -		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");
> -
> -	return 0;
> -}
> -
> -static int __devinit ricoh_mmc_probe(struct pci_dev *pdev,
> -				     const struct pci_device_id *ent)
> -{
> -	u8 rev;
> -	u8 ctrlfound = 0;
> -
> -	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_RL5C476, fw_dev))) {
> -		if (PCI_SLOT(pdev->devfn) == PCI_SLOT(fw_dev->devfn)
> &&
> -		    PCI_FUNC(fw_dev->devfn) == 0 &&
> -		    pdev->bus == fw_dev->bus) {
> -			if (ricoh_mmc_disable(fw_dev) != 0)
> -				return -ENODEV;
> -
> -			pci_set_drvdata(pdev, fw_dev);
> -
> -			++ctrlfound;
> -			break;
> -		}
> -	}
> -
> -	fw_dev = NULL;
> -
> -	while (!ctrlfound &&
> -	    (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)
> &&
> -		    PCI_FUNC(fw_dev->devfn) == 0 &&
> -		    pdev->bus == fw_dev->bus) {
> -			if (ricoh_mmc_disable(fw_dev) != 0)
> -				return -ENODEV;
> -
> -			pci_set_drvdata(pdev, fw_dev);
> -
> -			++ctrlfound;
> -		}
> -	}
> -
> -	if (!ctrlfound) {
> -		printk(KERN_WARNING DRIVER_NAME
> -		       ": Main Ricoh function not found. Cannot
> disable controller.\n");
> -		return -ENODEV;
> -	}
> -
> -	return 0;
> -}
> -
> -static void __devexit ricoh_mmc_remove(struct pci_dev *pdev)
> -{
> -	struct pci_dev *fw_dev = NULL;
> -
> -	fw_dev = pci_get_drvdata(pdev);
> -	BUG_ON(fw_dev == NULL);
> -
> -	ricoh_mmc_enable(fw_dev);
> -
> -	pci_set_drvdata(pdev, NULL);
> -}
> -
> -static int ricoh_mmc_suspend_late(struct pci_dev *pdev, pm_message_t
> state) -{
> -	struct pci_dev *fw_dev = NULL;
> -
> -	fw_dev = pci_get_drvdata(pdev);
> -	BUG_ON(fw_dev == NULL);
> -
> -	printk(KERN_INFO DRIVER_NAME ": Suspending.\n");
> -
> -	ricoh_mmc_enable(fw_dev);
> -
> -	return 0;
> -}
> -
> -static int ricoh_mmc_resume_early(struct pci_dev *pdev)
> -{
> -	struct pci_dev *fw_dev = NULL;
> -
> -	fw_dev = pci_get_drvdata(pdev);
> -	BUG_ON(fw_dev == NULL);
> -
> -	printk(KERN_INFO DRIVER_NAME ": Resuming.\n");
> -
> -	ricoh_mmc_disable(fw_dev);
> -
> -	return 0;
> -}
> -
> -static struct pci_driver ricoh_mmc_driver = {
> -	.name = 	DRIVER_NAME,
> -	.id_table =	pci_ids,
> -	.probe = 	ricoh_mmc_probe,
> -	.remove =	__devexit_p(ricoh_mmc_remove),
> -	.suspend_late =	ricoh_mmc_suspend_late,
> -	.resume_early =	ricoh_mmc_resume_early,
> -};
> -
> -/*****************************************************************************\
> -
> *
> *
> - * 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)
> -{
> -	pci_unregister_driver(&ricoh_mmc_driver);
> -}
> -
> -module_init(ricoh_mmc_drv_init);
> -module_exit(ricoh_mmc_drv_exit);
> -
> -MODULE_AUTHOR("Philip Langdale <philipl@...mni.utexas.net>");
> -MODULE_DESCRIPTION("Ricoh MMC Controller disabling driver");
> -MODULE_LICENSE("GPL");
> -
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index c746943..df08a2c 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -2520,6 +2520,88 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL,
> 0x150d, quirk_i82576_sriov); 
>  #endif	/* CONFIG_PCI_IOV */
>  
> +/*
> + * This is a quirk for Ricoh MMC controller found as a part of
> + * multifunction chip.
> +
> + * This is very similar and based on ricoh_mmc driver written by
> + * Philip Langdale. Thank you for these magic sequences.
> + *
> + * These chips implement the four main memory card
> + * controllers (SD, MMC, MS, xD) and one or both
> + * of cardbus or firewire. It happens that they implement SD and MMC
> + * support as separate controllers (and PCI functions). 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
> + * It seems to be the case that the relevant PCI registers to
> deactivate the
> + * MMC controller live on PCI function 0, which might be the cardbus
> controller
> + * or the firewire controller, depending on the particular chip in
> question +
> + * This has to be done early, because as soon as we disable the MMC
> controller
> + * other pci functions shift up one level, e.g. function #2 becomes
> function
> + * #1, and this will confuse the pci core.
> + */
> +
> +#ifdef CONFIG_MMC_RICOH_MMC
> +static void ricoh_mmc_fixup_rl5c476(struct pci_dev *dev)
> +{
> +	/* disable via cardbus interface */
> +	u8 write_enable;
> +	u8 write_target;
> +	u8 disable;
> +
> +	/* disable must be done via function #0 */
> +	if (PCI_FUNC(dev->devfn))
> +		return;
> +
> +	pci_read_config_byte(dev, 0xB7, &disable);
> +	if (disable & 0x02)
> +		return;
> +
> +	pci_read_config_byte(dev, 0x8E, &write_enable);
> +	pci_write_config_byte(dev, 0x8E, 0xAA);
> +	pci_read_config_byte(dev, 0x8D, &write_target);
> +	pci_write_config_byte(dev, 0x8D, 0xB7);
> +	pci_write_config_byte(dev, 0xB7, disable | 0x02);
> +	pci_write_config_byte(dev, 0x8E, write_enable);
> +	pci_write_config_byte(dev, 0x8D, write_target);
> +
> +	dev_notice(&dev->dev, "proprietary Ricoh mmc controller
> disabled (via cardbus function)\n");
> +	dev_notice(&dev->dev, "MMC cards are now supported by
> standard SDHCI controller\n"); +}
> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_RICOH,
> PCI_DEVICE_ID_RICOH_RL5C476, ricoh_mmc_fixup_rl5c476);
> +DECLARE_PCI_FIXUP_RESUME_EARLY(PCI_VENDOR_ID_RICOH,
> PCI_DEVICE_ID_RICOH_RL5C476, ricoh_mmc_fixup_rl5c476); + +static void
> ricoh_mmc_fixup_r5c832(struct pci_dev *dev) +{
> +	/* disable via firewire interface */
> +	u8 write_enable;
> +	u8 disable;
> +
> +	/* disable must be done via function #0 */
> +	if (PCI_FUNC(dev->devfn))
> +		return;
> +
> +	pci_read_config_byte(dev, 0xCB, &disable);
> +
> +	if (disable & 0x02)
> +		return;
> +
> +	pci_read_config_byte(dev, 0xCA, &write_enable);
> +	pci_write_config_byte(dev, 0xCA, 0x57);
> +	pci_write_config_byte(dev, 0xCB, disable | 0x02);
> +	pci_write_config_byte(dev, 0xCA, write_enable);
> +
> +	dev_notice(&dev->dev, "proprietary Ricoh mmc controller
> disabled (via firewire function)\n");
> +	dev_notice(&dev->dev, "MMC cards are now supported by
> standard SDHCI controller\n"); +}
> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_RICOH,
> PCI_DEVICE_ID_RICOH_R5C832, ricoh_mmc_fixup_r5c832);
> +DECLARE_PCI_FIXUP_RESUME_EARLY(PCI_VENDOR_ID_RICOH,
> PCI_DEVICE_ID_RICOH_R5C832, ricoh_mmc_fixup_r5c832);
> +#endif /*CONFIG_MMC_RICOH_MMC*/ + +
>  static void pci_do_fixups(struct pci_dev *dev, struct pci_fixup *f,
>  			  struct pci_fixup *end)
>  {




--phil
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