2021-05-12 19:49:46

by Rikard Falkeborn

Subject: [PATCH] pinctrl: at91: Constify struct at91_pinctrl_mux_ops

The at91_pinctrl_mux_ops struct is never modified by the driver. Make it
const wherever it is possible to allow the compiler to put the static
variables in read-only memory. Note that sam9x60_ops was already const,
but the const was cast away when the return value of of_match_device() was
cast to a pointer to a non-const struct at91_pinctrl_mux_ops.

Signed-off-by: Rikard Falkeborn <[email protected]>
---
drivers/pinctrl/pinctrl-at91.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-at91.c b/drivers/pinctrl/pinctrl-at91.c
index fc61aaec34cc..72e6df7abe8c 100644
--- a/drivers/pinctrl/pinctrl-at91.c
+++ b/drivers/pinctrl/pinctrl-at91.c
@@ -42,7 +42,7 @@ struct at91_gpio_chip {
int pioc_idx; /* PIO bank index */
void __iomem *regbase; /* PIO bank virtual address */
struct clk *clock; /* associated clock */
- struct at91_pinctrl_mux_ops *ops; /* ops */
+ const struct at91_pinctrl_mux_ops *ops; /* ops */
};

static struct at91_gpio_chip *gpio_chips[MAX_GPIO_BANKS];
@@ -210,7 +210,7 @@ struct at91_pinctrl {
struct at91_pin_group *groups;
int ngroups;

- struct at91_pinctrl_mux_ops *ops;
+ const struct at91_pinctrl_mux_ops *ops;
};

static inline const struct at91_pin_group *at91_pinctrl_find_group_by_name(
@@ -688,7 +688,7 @@ static void at91_mux_sam9x60_set_slewrate(void __iomem *pio, unsigned pin,
writel_relaxed(tmp, pio + SAM9X60_PIO_SLEWR);
}

-static struct at91_pinctrl_mux_ops at91rm9200_ops = {
+static const struct at91_pinctrl_mux_ops at91rm9200_ops = {
.get_periph = at91_mux_get_periph,
.mux_A_periph = at91_mux_set_A_periph,
.mux_B_periph = at91_mux_set_B_periph,
@@ -697,7 +697,7 @@ static struct at91_pinctrl_mux_ops at91rm9200_ops = {
.irq_type = gpio_irq_type,
};

-static struct at91_pinctrl_mux_ops at91sam9x5_ops = {
+static const struct at91_pinctrl_mux_ops at91sam9x5_ops = {
.get_periph = at91_mux_pio3_get_periph,
.mux_A_periph = at91_mux_pio3_set_A_periph,
.mux_B_periph = at91_mux_pio3_set_B_periph,
@@ -737,7 +737,7 @@ static const struct at91_pinctrl_mux_ops sam9x60_ops = {
.irq_type = alt_gpio_irq_type,
};

-static struct at91_pinctrl_mux_ops sama5d3_ops = {
+static const struct at91_pinctrl_mux_ops sama5d3_ops = {
.get_periph = at91_mux_pio3_get_periph,
.mux_A_periph = at91_mux_pio3_set_A_periph,
.mux_B_periph = at91_mux_pio3_set_B_periph,
@@ -1284,7 +1284,7 @@ static int at91_pinctrl_probe_dt(struct platform_device *pdev,
return -ENODEV;

info->dev = &pdev->dev;
- info->ops = (struct at91_pinctrl_mux_ops *)
+ info->ops = (const struct at91_pinctrl_mux_ops *)
of_match_device(at91_pinctrl_of_match, &pdev->dev)->data;
at91_pinctrl_child_count(info, np);

@@ -1849,7 +1849,7 @@ static int at91_gpio_probe(struct platform_device *pdev)
goto err;
}

- at91_chip->ops = (struct at91_pinctrl_mux_ops *)
+ at91_chip->ops = (const struct at91_pinctrl_mux_ops *)
of_match_device(at91_gpio_of_match, &pdev->dev)->data;
at91_chip->pioc_virq = irq;
at91_chip->pioc_idx = alias_idx;
--
2.31.1

2021-05-25 00:10:53

by Linus Walleij

Subject: Re: [PATCH] pinctrl: at91: Constify struct at91_pinctrl_mux_ops

On Wed, May 12, 2021 at 8:01 PM Rikard Falkeborn
<[email protected]> wrote:

> The at91_pinctrl_mux_ops struct is never modified by the driver. Make it
> const wherever it is possible to allow the compiler to put the static
> variables in read-only memory. Note that sam9x60_ops was already const,
> but the const was cast away when the return value of of_match_device() was
> cast to a pointer to a non-const struct at91_pinctrl_mux_ops.
>
> Signed-off-by: Rikard Falkeborn <[email protected]>

Patch applied.

Yours,
Linus Walleij