[PATCH 1/3][MTD] P4080/eLBC: Make Freescale elbc interrupt common to elbc devices

Zang Roy-R61911 r61911 at freescale.com
Sun Sep 5 23:38:09 EDT 2010



> -----Original Message-----
> From: Anton Vorontsov [mailto:cbouatmailru at gmail.com]
> Sent: Friday, September 03, 2010 19:28 PM
> To: Zang Roy-R61911
> Cc: linux-mtd at lists.infradead.org; Lan Chunhe-B25806; linuxppc-dev at ozlabs.org;
> akpm at linux-foundation.org; Gala Kumar-B11780
> Subject: Re: [PATCH 1/3][MTD] P4080/eLBC: Make Freescale elbc interrupt common
> to elbc devices
> 
> On Fri, Aug 06, 2010 at 10:51:34AM +0800, Roy Zang wrote:
> > From: Lan Chunhe-B25806 <b25806 at freescale.com>
> >
> > Move Freescale elbc interrupt from nand dirver to elbc driver.
> > Then all elbc devices can use the interrupt instead of ONLY nand.
> >
> > Signed-off-by: Lan Chunhe-B25806 <b25806 at freescale.com>
> > Signed-off-by: Roy Zang <tie-fei.zang at freescale.com>
> > ---
> > send the patch to linux-mtd at lists.infradead.org
> > it has been posted to linuxppc-dev at ozlabs.org and do not get any comment.
> >
> >  arch/powerpc/Kconfig               |    7 +-
> >  arch/powerpc/include/asm/fsl_lbc.h |   34 +++++-
> >  arch/powerpc/sysdev/fsl_lbc.c      |  254 ++++++++++++++++++++++++++++++---
> ---
> >  3 files changed, 253 insertions(+), 42 deletions(-)
> >
> > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> > index 2031a28..5155b53 100644
> > --- a/arch/powerpc/Kconfig
> > +++ b/arch/powerpc/Kconfig
> > @@ -703,9 +703,12 @@ config 4xx_SOC
> >  	bool
> >
> >  config FSL_LBC
> > -	bool
> > +	bool "Freescale Local Bus support"
> > +	depends on FSL_SOC
> >  	help
> > -	  Freescale Localbus support
> > +	  Enables reporting of errors from the Freescale local bus
> > +	  controller.  Also contains some common code used by
> > +	  drivers for specific local bus peripherals.
> >
> >  config FSL_GTM
> >  	bool
> [...]
> > diff --git a/arch/powerpc/sysdev/fsl_lbc.c b/arch/powerpc/sysdev/fsl_lbc.c
> > index dceb8d1..9c9e44f 100644
> > --- a/arch/powerpc/sysdev/fsl_lbc.c
> > +++ b/arch/powerpc/sysdev/fsl_lbc.c
> > @@ -5,6 +5,10 @@
> >   *
> >   * Author: Anton Vorontsov <avorontsov at ru.mvista.com>
> >   *
> > + * Copyright (c) 2010 Freescale Semiconductor
> > + *
> > + * Authors: Jack Lan <Jack.Lan at freescale.com>
> 
> Would be prettier if you'd group copyright and authorship notices.
> I.e.
> 
> Copyright 2008 MV
> Copyright 2010 FSL
> 
> Authors: Anton
>          Jack
Then how to reflect the relationship of the Author and the company? from email address?

> 
> > + *
> >   * 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
> > @@ -23,35 +27,8 @@
> >  #include <asm/fsl_lbc.h>
> >
> >  static spinlock_t fsl_lbc_lock = __SPIN_LOCK_UNLOCKED(fsl_lbc_lock);
> > -static struct fsl_lbc_regs __iomem *fsl_lbc_regs;
> > -
> > -static char __initdata *compat_lbc[] = {
> > -	"fsl,pq2-localbus",
> > -	"fsl,pq2pro-localbus",
> > -	"fsl,pq3-localbus",
> > -	"fsl,elbc",
> > -};
> > -
> > -static int __init fsl_lbc_init(void)
> > -{
> > -	struct device_node *lbus;
> > -	int i;
> > -
> > -	for (i = 0; i < ARRAY_SIZE(compat_lbc); i++) {
> > -		lbus = of_find_compatible_node(NULL, NULL, compat_lbc[i]);
> > -		if (lbus)
> > -			goto found;
> > -	}
> > -	return -ENODEV;
> > -
> > -found:
> > -	fsl_lbc_regs = of_iomap(lbus, 0);
> > -	of_node_put(lbus);
> > -	if (!fsl_lbc_regs)
> > -		return -ENOMEM;
> > -	return 0;
> > -}
> > -arch_initcall(fsl_lbc_init);
> > +struct fsl_lbc_ctrl *fsl_lbc_ctrl_dev;
> > +EXPORT_SYMBOL(fsl_lbc_ctrl_dev);
> >
> >  /**
> >   * fsl_lbc_find - find Localbus bank
> > @@ -66,12 +43,12 @@ int fsl_lbc_find(phys_addr_t addr_base)
> >  {
> >  	int i;
> >
> > -	if (!fsl_lbc_regs)
> > +	if (!fsl_lbc_ctrl_dev || !fsl_lbc_ctrl_dev->regs)
> >  		return -ENODEV;
> >
> > -	for (i = 0; i < ARRAY_SIZE(fsl_lbc_regs->bank); i++) {
> > -		__be32 br = in_be32(&fsl_lbc_regs->bank[i].br);
> > -		__be32 or = in_be32(&fsl_lbc_regs->bank[i].or);
> > +	for (i = 0; i < ARRAY_SIZE(fsl_lbc_ctrl_dev->regs->bank); i++) {
> > +		__be32 br = in_be32(&fsl_lbc_ctrl_dev->regs->bank[i].br);
> > +		__be32 or = in_be32(&fsl_lbc_ctrl_dev->regs->bank[i].or);
> 
> A dedicated variable for regs would make this much more readable?
Yes. considering the following condition line.
> 
> >
> >  		if (br & BR_V && (br & or & BR_BA) == addr_base)
> >  			return i;
> > @@ -99,17 +76,20 @@ int fsl_upm_find(phys_addr_t addr_base, struct fsl_upm
> *upm)
> >  	if (bank < 0)
> >  		return bank;
> >
> > -	br = in_be32(&fsl_lbc_regs->bank[bank].br);
> > +	if (!fsl_lbc_ctrl_dev || !fsl_lbc_ctrl_dev->regs)
> > +		return -ENODEV;
> > +
> > +	br = in_be32(&fsl_lbc_ctrl_dev->regs->bank[bank].br);
> >
> >  	switch (br & BR_MSEL) {
> >  	case BR_MS_UPMA:
> > -		upm->mxmr = &fsl_lbc_regs->mamr;
> > +		upm->mxmr = &fsl_lbc_ctrl_dev->regs->mamr;
> 
> Ditto, a very repetitive stuff, desires a variable for regs?
But the fact is that the variable represents different reg address according to the condition. It will be ugly to use the reg address directoly.
> 
> >  		break;
> >  	case BR_MS_UPMB:
> > -		upm->mxmr = &fsl_lbc_regs->mbmr;
> > +		upm->mxmr = &fsl_lbc_ctrl_dev->regs->mbmr;
> >  		break;
> >  	case BR_MS_UPMC:
> > -		upm->mxmr = &fsl_lbc_regs->mcmr;
> > +		upm->mxmr = &fsl_lbc_ctrl_dev->regs->mcmr;
> >  		break;
> >  	default:
> >  		return -EINVAL;
> > @@ -143,14 +123,18 @@ EXPORT_SYMBOL(fsl_upm_find);
> >   * thus UPM pattern actually executed. Note that mar usage depends on the
> >   * pre-programmed AMX bits in the UPM RAM.
> >   */
> > +
> >  int fsl_upm_run_pattern(struct fsl_upm *upm, void __iomem *io_base, u32 mar)
> >  {
> >  	int ret = 0;
> >  	unsigned long flags;
> >
> > +	if (!fsl_lbc_ctrl_dev || !fsl_lbc_ctrl_dev->regs)
> > +		return -ENODEV;
> > +
> >  	spin_lock_irqsave(&fsl_lbc_lock, flags);
> >
> > -	out_be32(&fsl_lbc_regs->mar, mar);
> > +	out_be32(&fsl_lbc_ctrl_dev->regs->mar, mar);
> >
> >  	switch (upm->width) {
> >  	case 8:
> > @@ -172,3 +156,197 @@ int fsl_upm_run_pattern(struct fsl_upm *upm, void
> __iomem *io_base, u32 mar)
> >  	return ret;
> >  }
> >  EXPORT_SYMBOL(fsl_upm_run_pattern);
> > +
> > +static int __devinit fsl_lbc_ctrl_init(struct fsl_lbc_ctrl *ctrl)
> > +{
> > +	struct fsl_lbc_regs __iomem *lbc = ctrl->regs;
> 
> Yep, something like this for the functions above.
I do not see any harm to add a variable lbc in the function to increase the readable.
> 
> > +
> > +	/* clear event registers */
> > +	setbits32(&lbc->ltesr, LTESR_CLEAR);
> > +	out_be32(&lbc->lteatr, 0);
> > +	out_be32(&lbc->ltear, 0);
> > +	out_be32(&lbc->lteccr, LTECCR_CLEAR);
> > +	out_be32(&lbc->ltedr, LTEDR_ENABLE);
> > +
> > +	/* Enable interrupts for any detected events */
> > +	out_be32(&lbc->lteir, LTEIR_ENABLE);
> > +
> > +	return 0;
> > +}
> > +
> > +static int __devexit fsl_lbc_ctrl_remove(struct of_device *ofdev)
> > +{
> > +	struct fsl_lbc_ctrl *ctrl = dev_get_drvdata(&ofdev->dev);
> > +
> > +	if (ctrl->irq)
> > +		free_irq(ctrl->irq, ctrl);
> > +
> > +	if (ctrl->regs)
> > +		iounmap(ctrl->regs);
> > +
> > +	dev_set_drvdata(&ofdev->dev, NULL);
> > +	kfree(ctrl);
> > +
> > +	return 0;
> > +}
> > +
> > +/* NOTE: This interrupt is used to report localbus events of various kinds,
> > + * such as transaction errors on the chipselects.
> > + */
> 
> /*
>  * multi line comments
>  * should be like this
>  */
OK.

> 
> [...]
> > +/* fsl_lbc_ctrl_probe
> > + *
> > + * called by device layer when it finds a device matching
> > + * one our driver can handled. This code allocates all of
> > + * the resources needed for the controller only.  The
> > + * resources for the NAND banks themselves are allocated
> > + * in the chip probe function.
> > +*/
> 
> ditto.
OK.
> 
> > +static int __devinit fsl_lbc_ctrl_probe(struct of_device *ofdev,
> > +					 const struct of_device_id *match)
> > +{
> > +	int ret = 0;
> 
> no need for the initial value here.
Any harm?

> 
> > +
> > +	fsl_lbc_ctrl_dev = kzalloc(sizeof(*fsl_lbc_ctrl_dev), GFP_KERNEL);
> > +	if (!fsl_lbc_ctrl_dev)
> > +		return -ENOMEM;
> > +
> > +	dev_set_drvdata(&ofdev->dev, fsl_lbc_ctrl_dev);
> > +
> > +	spin_lock_init(&fsl_lbc_ctrl_dev->lock);
> > +	init_waitqueue_head(&fsl_lbc_ctrl_dev->irq_wait);
> > +
> > +	fsl_lbc_ctrl_dev->regs = of_iomap(ofdev->dev.of_node, 0);
> > +	if (!fsl_lbc_ctrl_dev->regs) {
> > +		dev_err(&ofdev->dev, "failed to get memory region\n");
> > +		ret = -ENODEV;
> > +		goto err;
> > +	}
> > +
> > +	fsl_lbc_ctrl_dev->irq = of_irq_to_resource(ofdev->dev.of_node, 0, NULL);
> > +	if (fsl_lbc_ctrl_dev->irq == NO_IRQ) {
> > +		dev_err(&ofdev->dev, "failed to get irq resource\n");
> > +		ret = -ENODEV;
> > +		goto err;
> > +	}
> > +
> > +	fsl_lbc_ctrl_dev->dev = &ofdev->dev;
> > +
> > +	ret = fsl_lbc_ctrl_init(fsl_lbc_ctrl_dev);
> > +	if (ret < 0)
> > +		goto err;
> > +
> > +	ret = request_irq(fsl_lbc_ctrl_dev->irq, fsl_lbc_ctrl_irq, 0,
> > +				"fsl-lbc", fsl_lbc_ctrl_dev);
> > +	if (ret != 0) {
> > +		dev_err(&ofdev->dev, "failed to install irq (%d)\n",
> > +			fsl_lbc_ctrl_dev->irq);
> > +		ret = fsl_lbc_ctrl_dev->irq;
> > +		goto err;
> > +	}
> > +
> > +	return 0;
> > +
> > +err:
> 
> fsl_lbc_ctrl_dev leaked. Plus, after freeing it, you should
> NULLify it as well, as other functions checks it for !NULL.
Agree.
> 
> fsl_lbc_ctrl_dev->regs leaks too.
Agree.
> 
> > +	return ret;
> > +}
> > +
> > +static const struct of_device_id fsl_lbc_match[] = {
> > +	{
> > +		.compatible = "fsl,elbc",
> > +	},
> > +	{
> > +		.compatible = "fsl,pq3-localbus",
> > +	},
> > +	{
> > +		.compatible = "fsl,pq2-localbus",
> > +	},
> > +	{
> > +		.compatible = "fsl,pq2pro-localbus",
> > +	},
> > +	{},
> 
> Could save 8 lines by writing "{ .compatible = "...", },".

Agree.
> 
> > +};
> > +
> > +static struct of_platform_driver fsl_lbc_ctrl_driver = {
> 
> I think you shouldn't use of_platform for new code. just platform
> will work (there's platform_driver.driver.of_match_table nowadays).
> 
> > +	.driver = {
> > +		.name = "fsl-lbc",
> > +		.of_match_table = fsl_lbc_match,
> > +	},
> > +	.probe = fsl_lbc_ctrl_probe,
> > +	.remove = __devexit_p(fsl_lbc_ctrl_remove),
> 
> The device is not removable, I think you don't need this.
Agree.

> 
> > +};
> > +
> > +static int __init fsl_lbc_init(void)
> > +{
> > +	return of_register_platform_driver(&fsl_lbc_ctrl_driver);
> > +}
> > +
> > +static void __exit fsl_lbc_exit(void)
> > +{
> > +	of_unregister_platform_driver(&fsl_lbc_ctrl_driver);
> > +}
> > +
> > +module_init(fsl_lbc_init);
> > +module_exit(fsl_lbc_exit);
> 
> fsl_lbc is not a module, so you don't need _exit().
Agree.
> 
> > +MODULE_LICENSE("GPL");
> > +MODULE_AUTHOR("Freescale Semiconductor");
> > +MODULE_DESCRIPTION("Freescale Enhanced Local Bus Controller driver");
> 
> ditto, no need for this.
Agree.
Thanks.
Roy


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