From: stigge@antcom•de (Roland Stigge)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH RESEND 0/6 v10] gpio: Add block GPIO
Date: Mon, 17 Dec 2012 22:33:29 +0100 [thread overview]
Message-ID: <50CF8FA9.8050609@antcom.de> (raw)
In-Reply-To: <50CF76D3.9030708@grandegger.com>
On 17/12/12 20:47, Wolfgang Grandegger wrote:
> On 12/17/2012 07:02 PM, Roland Stigge wrote:
>> On 12/17/2012 06:37 PM, Wolfgang Grandegger wrote:
>>> /* Do synchronous data output with a single write access */
>>> __raw_writel(~mask, pio + PIO_OWDR);
>>> __raw_writel(mask, pio + PIO_OWER);
>>> __raw_writel(val, pio + PIO_ODSR);
>>>
>>> For caching we would need a storage. Not sure if it's worth compared to
>>> a context switch into the kernel.
>>
>> Block GPIO is not only for you in userspace. ;-) You can also implement
>> efficient n-bit bus I/O in kernel drivers, n-bit-banging. :-) So not
>> always context switches involved.
>
> OK, what do you think about the following untested patch:
Looks good!
Why "untested"? ;-)
Thanks,
Roland
>>From b44cad16cbbca84715dffd4cb5268497216add25 Mon Sep 17 00:00:00 2001
> From: Wolfgang Grandegger <wg@grandegger•com>
> Date: Mon, 3 Dec 2012 08:31:55 +0100
> Subject: [PATCH 1/2] gpio: add GPIO block callback functions for AT91
>
> Signed-off-by: Wolfgang Grandegger <wg@grandegger•com>
> ---
> arch/arm/mach-at91/gpio.c | 29 +++++++++++++++++++++++++++++
> 1 file changed, 29 insertions(+)
>
> diff --git a/arch/arm/mach-at91/gpio.c b/arch/arm/mach-at91/gpio.c
> index be42cf0..cf6bd45 100644
> --- a/arch/arm/mach-at91/gpio.c
> +++ b/arch/arm/mach-at91/gpio.c
> @@ -42,13 +42,16 @@ struct at91_gpio_chip {
> void __iomem *regbase; /* PIO bank virtual address */
> struct clk *clock; /* associated clock */
> struct irq_domain *domain; /* associated irq domain */
> + unsigned long mask_shadow; /* synchronous data output */
> };
>
> #define to_at91_gpio_chip(c) container_of(c, struct at91_gpio_chip, chip)
>
> static void at91_gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip);
> static void at91_gpiolib_set(struct gpio_chip *chip, unsigned offset, int val);
> +static void at91_gpiolib_set_block(struct gpio_chip *chip, unsigned long mask, unsigned long val);
> static int at91_gpiolib_get(struct gpio_chip *chip, unsigned offset);
> +static unsigned long at91_gpiolib_get_block(struct gpio_chip *chip, unsigned long mask);
> static int at91_gpiolib_direction_output(struct gpio_chip *chip,
> unsigned offset, int val);
> static int at91_gpiolib_direction_input(struct gpio_chip *chip,
> @@ -62,7 +65,9 @@ static int at91_gpiolib_to_irq(struct gpio_chip *chip, unsigned offset);
> .direction_input = at91_gpiolib_direction_input, \
> .direction_output = at91_gpiolib_direction_output, \
> .get = at91_gpiolib_get, \
> + .get_block = at91_gpiolib_get_block, \
> .set = at91_gpiolib_set, \
> + .set_block = at91_gpiolib_set_block, \
> .dbg_show = at91_gpiolib_dbg_show, \
> .to_irq = at91_gpiolib_to_irq, \
> .ngpio = nr_gpio, \
> @@ -896,6 +901,16 @@ static int at91_gpiolib_get(struct gpio_chip *chip, unsigned offset)
> return (pdsr & mask) != 0;
> }
>
> +static unsigned long at91_gpiolib_get_block(struct gpio_chip *chip, unsigned long mask)
> +{
> + struct at91_gpio_chip *at91_gpio = to_at91_gpio_chip(chip);
> + void __iomem *pio = at91_gpio->regbase;
> + u32 pdsr;
> +
> + pdsr = __raw_readl(pio + PIO_PDSR);
> + return pdsr & mask;
> +}
> +
> static void at91_gpiolib_set(struct gpio_chip *chip, unsigned offset, int val)
> {
> struct at91_gpio_chip *at91_gpio = to_at91_gpio_chip(chip);
> @@ -905,6 +920,20 @@ static void at91_gpiolib_set(struct gpio_chip *chip, unsigned offset, int val)
> __raw_writel(mask, pio + (val ? PIO_SODR : PIO_CODR));
> }
>
> +static void at91_gpiolib_set_block(struct gpio_chip *chip, unsigned long mask, unsigned long val)
> +{
> + struct at91_gpio_chip *at91_gpio = to_at91_gpio_chip(chip);
> + void __iomem *pio = at91_gpio->regbase;
> +
> + /* Do synchronous data output with a single write access */
> + if (mask != at91_gpio->mask_shadow) {
> + at91_gpio->mask_shadow = mask;
> + __raw_writel(~mask, pio + PIO_OWDR);
> + __raw_writel(mask, pio + PIO_OWER);
> + }
> + __raw_writel(val, pio + PIO_ODSR);
> +}
> +
> static void at91_gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
> {
> int i;
next prev parent reply other threads:[~2012-12-17 21:33 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-14 14:26 [PATCH RESEND 0/6 v10] gpio: Add block GPIO Roland Stigge
2012-12-14 14:26 ` [PATCH RESEND 1/6 v10] gpio: Add a block GPIO API to gpiolib Roland Stigge
2012-12-14 14:26 ` [PATCH RESEND 2/6 v10] gpio: Add sysfs support to block GPIO API Roland Stigge
2012-12-14 14:26 ` [PATCH RESEND 3/6 v10] gpio: Add userland device interface to block GPIO Roland Stigge
2012-12-14 14:26 ` [PATCH RESEND 4/6 v10] gpiolib: Fix default attributes for class Roland Stigge
2012-12-14 14:26 ` [PATCH RESEND 5/6 v10] gpio: Add device tree support to block GPIO API Roland Stigge
2012-12-17 15:51 ` Mark Rutland
2012-12-18 14:30 ` Roland Stigge
2012-12-18 16:35 ` Mark Rutland
2012-12-14 14:26 ` [PATCH RESEND 6/6 v10] gpio: Add block gpio to several gpio drivers Roland Stigge
2012-12-14 17:58 ` [PATCH RESEND 0/6 v10] gpio: Add block GPIO Wolfgang Grandegger
2012-12-14 23:49 ` Roland Stigge
2012-12-15 10:51 ` Russell King - ARM Linux
2012-12-17 11:37 ` Wolfgang Grandegger
2012-12-17 11:51 ` Wolfgang Grandegger
2012-12-17 12:10 ` Russell King - ARM Linux
2012-12-17 14:57 ` Wolfgang Grandegger
2012-12-17 13:32 ` Roland Stigge
2012-12-17 13:51 ` Roland Stigge
2012-12-17 16:28 ` Wolfgang Grandegger
2012-12-17 17:15 ` Roland Stigge
2012-12-17 17:37 ` Wolfgang Grandegger
2012-12-17 18:02 ` Roland Stigge
2012-12-17 19:47 ` Wolfgang Grandegger
2012-12-17 21:33 ` Roland Stigge [this message]
2012-12-18 6:51 ` Wolfgang Grandegger
2012-12-18 5:55 ` Jean-Christophe PLAGNIOL-VILLARD
2012-12-18 6:58 ` Wolfgang Grandegger
2012-12-18 7:54 ` Jean-Christophe PLAGNIOL-VILLARD
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