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Date: Thu, 18 Sep 2014 14:17:05 +0300
From: Mika Westerberg <mika.westerberg@...ux.intel.com>
To: Chang Rebecca Swee Fun <rebecca.swee.fun.chang@...el.com>
Cc: Linus Walleij <linus.walleij@...aro.org>,
linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/3] gpio: sch: Consolidate similar algorithms
On Wed, Sep 17, 2014 at 04:49:03PM +0800, Chang Rebecca Swee Fun wrote:
> Consolidating similar algorithms into common functions to make
> GPIO SCH simpler and manageable.
>
> Signed-off-by: Chang Rebecca Swee Fun <rebecca.swee.fun.chang@...el.com>
> ---
> drivers/gpio/gpio-sch.c | 95 ++++++++++++++++++++++++++---------------------
> 1 file changed, 53 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/gpio/gpio-sch.c b/drivers/gpio/gpio-sch.c
> index 99720c8..2189c22 100644
> --- a/drivers/gpio/gpio-sch.c
> +++ b/drivers/gpio/gpio-sch.c
> @@ -43,6 +43,8 @@ struct sch_gpio {
>
> #define to_sch_gpio(c) container_of(c, struct sch_gpio, chip)
>
> +static void sch_gpio_set(struct gpio_chip *gc, unsigned gpio_num, int val);
> +
Is it possible to move the sch_gpio_set() function here instead of
forward declaring it?
> static unsigned sch_gpio_offset(struct sch_gpio *sch, unsigned gpio,
> unsigned reg)
> {
> @@ -63,94 +65,89 @@ static unsigned sch_gpio_bit(struct sch_gpio *sch, unsigned gpio)
> return gpio % 8;
> }
>
> -static void sch_gpio_enable(struct sch_gpio *sch, unsigned gpio)
> +static void sch_gpio_enable(struct sch_gpio *sch, unsigned gpio, unsigned reg)
I don't see much value in doing this.
To me sch_gpio_enable(sch, gpio) is more intuitive than
sch_gpio_enable(sch, gpio, GEN). Why do I need to pass register to
enable function in the first place? It should know better how to enable
the GPIO, right?
Same goes for others.
> {
> unsigned short offset, bit;
> u8 enable;
>
> spin_lock(&sch->lock);
>
> - offset = sch_gpio_offset(sch, gpio, GEN);
> + offset = sch_gpio_offset(sch, gpio, reg);
> bit = sch_gpio_bit(sch, gpio);
>
> enable = inb(sch->iobase + offset);
> - if (!(enable & (1 << bit)))
> - outb(enable | (1 << bit), sch->iobase + offset);
> + if (!(enable & BIT(bit)))
> + outb(enable | BIT(bit), sch->iobase + offset);
>
> spin_unlock(&sch->lock);
> }
>
> -static int sch_gpio_direction_in(struct gpio_chip *gc, unsigned gpio_num)
> +static void sch_gpio_disable(struct sch_gpio *sch, unsigned gpio, unsigned reg)
> {
> - struct sch_gpio *sch = to_sch_gpio(gc);
> - u8 curr_dirs;
> unsigned short offset, bit;
> + u8 disable;
>
> spin_lock(&sch->lock);
>
> - offset = sch_gpio_offset(sch, gpio_num, GIO);
> - bit = sch_gpio_bit(sch, gpio_num);
> -
> - curr_dirs = inb(sch->iobase + offset);
> + offset = sch_gpio_offset(sch, gpio, reg);
> + bit = sch_gpio_bit(sch, gpio);
>
> - if (!(curr_dirs & (1 << bit)))
> - outb(curr_dirs | (1 << bit), sch->iobase + offset);
> + disable = inb(sch->iobase + offset);
> + if (disable & BIT(bit))
> + outb(disable & ~BIT(bit), sch->iobase + offset);
>
> spin_unlock(&sch->lock);
> - return 0;
> }
>
> -static int sch_gpio_get(struct gpio_chip *gc, unsigned gpio_num)
> +static int sch_gpio_reg_get(struct gpio_chip *gc, unsigned gpio, unsigned reg)
> {
> struct sch_gpio *sch = to_sch_gpio(gc);
> - int res;
> unsigned short offset, bit;
> + u8 curr_dirs;
>
> - offset = sch_gpio_offset(sch, gpio_num, GLV);
> - bit = sch_gpio_bit(sch, gpio_num);
> + offset = sch_gpio_offset(sch, gpio, reg);
> + bit = sch_gpio_bit(sch, gpio);
>
> - res = !!(inb(sch->iobase + offset) & (1 << bit));
> + curr_dirs = !!(inb(sch->iobase + offset) & BIT(bit));
>
> - return res;
> + return curr_dirs;
> }
>
> -static void sch_gpio_set(struct gpio_chip *gc, unsigned gpio_num, int val)
> +static void sch_gpio_reg_set(struct gpio_chip *gc, unsigned gpio, unsigned reg,
> + int val)
> {
> struct sch_gpio *sch = to_sch_gpio(gc);
> - u8 curr_vals;
> unsigned short offset, bit;
> + u8 curr_dirs;
>
> - spin_lock(&sch->lock);
> -
> - offset = sch_gpio_offset(sch, gpio_num, GLV);
> - bit = sch_gpio_bit(sch, gpio_num);
> + offset = sch_gpio_offset(sch, gpio, reg);
> + bit = sch_gpio_bit(sch, gpio);
>
> - curr_vals = inb(sch->iobase + offset);
> + curr_dirs = inb(sch->iobase + offset);
>
> if (val)
> - outb(curr_vals | (1 << bit), sch->iobase + offset);
> + outb(curr_dirs | BIT(bit), sch->iobase + offset);
> else
> - outb((curr_vals & ~(1 << bit)), sch->iobase + offset);
> + outb((curr_dirs & ~BIT(bit)), sch->iobase + offset);
> +}
> +
> +static int sch_gpio_direction_in(struct gpio_chip *gc, unsigned gpio_num)
> +{
> + struct sch_gpio *sch = to_sch_gpio(gc);
>
> + spin_lock(&sch->lock);
> + sch_gpio_enable(sch, gpio_num, GIO);
> spin_unlock(&sch->lock);
> + return 0;
> }
>
> static int sch_gpio_direction_out(struct gpio_chip *gc, unsigned gpio_num,
> int val)
> {
> struct sch_gpio *sch = to_sch_gpio(gc);
> - u8 curr_dirs;
> - unsigned short offset, bit;
>
> spin_lock(&sch->lock);
> -
> - offset = sch_gpio_offset(sch, gpio_num, GIO);
> - bit = sch_gpio_bit(sch, gpio_num);
> -
> - curr_dirs = inb(sch->iobase + offset);
> - if (curr_dirs & (1 << bit))
> - outb(curr_dirs & ~(1 << bit), sch->iobase + offset);
> -
> + sch_gpio_disable(sch, gpio_num, GIO);
> spin_unlock(&sch->lock);
>
> /*
> @@ -166,6 +163,20 @@ static int sch_gpio_direction_out(struct gpio_chip *gc, unsigned gpio_num,
> return 0;
> }
>
> +static int sch_gpio_get(struct gpio_chip *gc, unsigned gpio_num)
> +{
> + return sch_gpio_reg_get(gc, gpio_num, GLV);
> +}
> +
> +static void sch_gpio_set(struct gpio_chip *gc, unsigned gpio_num, int val)
> +{
> + struct sch_gpio *sch = to_sch_gpio(gc);
> +
> + spin_lock(&sch->lock);
> + sch_gpio_reg_set(gc, gpio_num, GLV, val);
> + spin_unlock(&sch->lock);
> +}
> +
> static struct gpio_chip sch_gpio_chip = {
> .label = "sch_gpio",
> .owner = THIS_MODULE,
> @@ -209,13 +220,13 @@ static int sch_gpio_probe(struct platform_device *pdev)
> * GPIO7 is configured by the CMC as SLPIOVR
> * Enable GPIO[9:8] core powered gpios explicitly
> */
> - sch_gpio_enable(sch, 8);
> - sch_gpio_enable(sch, 9);
> + sch_gpio_enable(sch, 8, GEN);
> + sch_gpio_enable(sch, 9, GEN);
For example here, which one is more readable?
> /*
> * SUS_GPIO[2:0] enabled by default
> * Enable SUS_GPIO3 resume powered gpio explicitly
> */
> - sch_gpio_enable(sch, 13);
> + sch_gpio_enable(sch, 13, GEN);
Or here?
> break;
>
> case PCI_DEVICE_ID_INTEL_ITC_LPC:
> --
> 1.7.9.5
>
> --
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