Re: [PATCH 1/3] gpio-langwell: cleanup driver

From: David Cohen
Date: Thu Dec 20 2012 - 16:35:37 EST


On 12/19/2012 05:18 PM, Grant Likely wrote:
On Tue, 18 Dec 2012 17:52:11 -0800, David Cohen <david.a.cohen@xxxxxxxxx> wrote:
This patch cleans up cosmetic issues, remove useless functions and add
to_lnw_priv() macro to replace many usages of container_of().

Change-Id: I70a8fadd20a42493271d91633739bdddff19c8d8
Signed-off-by: David Cohen <david.a.cohen@xxxxxxxxx>
Hi David. Comments below...

Hi Grant,

Thanks for comments. Let me go through them.


---
drivers/gpio/gpio-langwell.c | 64 ++++++++++++++----------------------------
1 file changed, 21 insertions(+), 43 deletions(-)

diff --git a/drivers/gpio/gpio-langwell.c b/drivers/gpio/gpio-langwell.c
index 202a992..8220c04 100644
--- a/drivers/gpio/gpio-langwell.c
+++ b/drivers/gpio/gpio-langwell.c
@@ -71,10 +71,12 @@ struct lnw_gpio {
struct irq_domain *domain;
};
+#define to_lnw_priv(chip) container_of(chip, struct lnw_gpio, chip)
+
static void __iomem *gpio_reg(struct gpio_chip *chip, unsigned offset,
enum GPIO_REG reg_type)
{
- struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
+ struct lnw_gpio *lnw = to_lnw_priv(chip);
unsigned nreg = chip->ngpio / 32;
u8 reg = offset / 32;
void __iomem *ptr;
@@ -86,7 +88,7 @@ static void __iomem *gpio_reg(struct gpio_chip *chip, unsigned offset,
static void __iomem *gpio_reg_2bit(struct gpio_chip *chip, unsigned offset,
enum GPIO_REG reg_type)
{
- struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
+ struct lnw_gpio *lnw = to_lnw_priv(chip);
unsigned nreg = chip->ngpio / 32;
u8 reg = offset / 16;
void __iomem *ptr;
@@ -130,7 +132,7 @@ static void lnw_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
static int lnw_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
- struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
+ struct lnw_gpio *lnw = to_lnw_priv(chip);
void __iomem *gpdr = gpio_reg(chip, offset, GPDR);
u32 value;
unsigned long flags;
@@ -153,7 +155,7 @@ static int lnw_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
static int lnw_gpio_direction_output(struct gpio_chip *chip,
unsigned offset, int value)
{
- struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
+ struct lnw_gpio *lnw = to_lnw_priv(chip);
void __iomem *gpdr = gpio_reg(chip, offset, GPDR);
unsigned long flags;
@@ -176,7 +178,7 @@ static int lnw_gpio_direction_output(struct gpio_chip *chip,
static int lnw_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
- struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
+ struct lnw_gpio *lnw = to_lnw_priv(chip);
return irq_create_mapping(lnw->domain, offset);
}
Nice cleanup above.

@@ -215,19 +217,14 @@ static int lnw_irq_type(struct irq_data *d, unsigned type)
return 0;
}
-static void lnw_irq_unmask(struct irq_data *d)
-{
-}
-
-static void lnw_irq_mask(struct irq_data *d)
-{
-}
+static void lnw_irq_noop(struct irq_data *d) {}
Umm, this looks entirely wrong. There needs to be either mask/unmask or
enable/disable ops for irq_chips. Yes I see that this patch is just
consolidating two empty functions, but they are two empty functions that
appear to be completely wrong.

I see your point. The solution does not belong to a clean up patch,
so I'll just remove it from here.


static struct irq_chip lnw_irqchip = {
.name = "LNW-GPIO",
- .irq_mask = lnw_irq_mask,
- .irq_unmask = lnw_irq_unmask,
+ .irq_mask = lnw_irq_noop,
+ .irq_unmask = lnw_irq_noop,
.irq_set_type = lnw_irq_type,
+ .irq_ack = lnw_irq_noop,
};
static DEFINE_PCI_DEVICE_TABLE(lnw_gpio_ids) = { /* pin number */
@@ -299,17 +296,6 @@ static const struct irq_domain_ops lnw_gpio_irq_ops = {
.xlate = irq_domain_xlate_twocell,
};
-#ifdef CONFIG_PM
-static int lnw_gpio_runtime_resume(struct device *dev)
-{
- return 0;
-}
-
-static int lnw_gpio_runtime_suspend(struct device *dev)
-{
- return 0;
-}
-
static int lnw_gpio_runtime_idle(struct device *dev)
{
int err = pm_schedule_suspend(dev, 500);
@@ -320,16 +306,8 @@ static int lnw_gpio_runtime_idle(struct device *dev)
return -EBUSY;
}
-#else
-#define lnw_gpio_runtime_suspend NULL
-#define lnw_gpio_runtime_resume NULL
-#define lnw_gpio_runtime_idle NULL
-#endif
-
static const struct dev_pm_ops lnw_gpio_pm_ops = {
- .runtime_suspend = lnw_gpio_runtime_suspend,
- .runtime_resume = lnw_gpio_runtime_resume,
- .runtime_idle = lnw_gpio_runtime_idle,
+ SET_RUNTIME_PM_OPS(NULL, NULL, lnw_gpio_runtime_idle)
};
Also good.

static int __devinit lnw_gpio_probe(struct pci_dev *pdev,
@@ -349,7 +327,7 @@ static int __devinit lnw_gpio_probe(struct pci_dev *pdev,
retval = pci_request_regions(pdev, "langwell_gpio");
if (retval) {
dev_err(&pdev->dev, "error requesting resources\n");
- goto err2;
+ goto err;
Renaming the labels just increases the noise in the diff. I prefer to
see labels in the form "err-what-i-just-tried-to-do:" so they don't need
to get reshuffled every time the code logic changes.

There is no good reason for this change. Please drop it.

Maybe instead of drop it I'd prefer to fix the labels. They
are wrong currently.

Br, David


g.
.


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