Re: [PATCH v4 4/7] gpio: gpio-aspeed-sgpio: Add AST2600 sgpio support

From: Andrew Jeffery
Date: Mon Jun 07 2021 - 19:44:26 EST




On Mon, 7 Jun 2021, at 16:45, Steven Lee wrote:
> AST2600 SoC has 2 SGPIO master interfaces one with 128 pins another one
> with 80 pins.
> In the current driver, the maximum number of gpio pins of SoC is hardcoded
> as 80 and the gpio pin count mask for GPIO Configuration register is
> hardcode as GENMASK(9,6). In addition, some functions use the hardcoded
> value to calculate the gpio offset.
> The patch adds ast2600 compatibles and platform data that includes the
> max number of gpio pins supported by ast2600 and gpio pin count mask for
> GPIO Configuration register.
> The patch also modifies some functions to pass aspeed_sgpio struct for
> calculating gpio offset without using the hardcoded value.
>
> Signed-off-by: Steven Lee <steven_lee@xxxxxxxxxxxxxx>
> ---
> drivers/gpio/gpio-aspeed-sgpio.c | 110 +++++++++++++++++++++----------
> 1 file changed, 76 insertions(+), 34 deletions(-)
>
> diff --git a/drivers/gpio/gpio-aspeed-sgpio.c b/drivers/gpio/gpio-aspeed-sgpio.c
> index 64e54f8c30d2..8b893356f0ca 100644
> --- a/drivers/gpio/gpio-aspeed-sgpio.c
> +++ b/drivers/gpio/gpio-aspeed-sgpio.c
> @@ -35,12 +35,18 @@
> #define ASPEED_SGPIO_CLK_DIV_MASK GENMASK(31, 16)
> #define ASPEED_SGPIO_ENABLE BIT(0)
>
> +struct aspeed_sgpio_pdata {
> + const u32 pin_mask;
> + int max_ngpios;
> +};
> +
> struct aspeed_sgpio {
> struct gpio_chip chip;
> struct clk *pclk;
> spinlock_t lock;
> void __iomem *base;
> int irq;
> + int max_ngpios;
> int n_sgpio;
> };
>
> @@ -75,7 +81,13 @@ static const struct aspeed_sgpio_bank
> aspeed_sgpio_banks[] = {
> .val_regs = 0x0038,
> .rdata_reg = 0x0078,
> .irq_regs = 0x003C,
> - .names = { "I", "J" },
> + .names = { "I", "J", "K", "L" },
> + },
> + {
> + .val_regs = 0x0090,
> + .rdata_reg = 0x007C,
> + .irq_regs = 0x0094,
> + .names = { "M", "N", "O", "P" },
> },
> };
>
> @@ -121,15 +133,15 @@ static void __iomem *bank_reg(struct aspeed_sgpio *gpio,
> }
> }
>
> -#define GPIO_BANK(x) ((x % SGPIO_OUTPUT_OFFSET) >> 5)
> -#define GPIO_OFFSET(x) ((x % SGPIO_OUTPUT_OFFSET) & 0x1f)
> -#define GPIO_BIT(x) BIT(GPIO_OFFSET(x))
> +#define GPIO_BANK(x, gpio) ((x % (gpio)->max_ngpios) >> 5)

I couldn't stop myself from commenting on this: The 'context' parameter should be first (by convention), so:

#define GPIO_BANK(gpio, x) ((x % (gpio)->max_ngpios) >> 5)

There's another fix necessary here too - the x needs to be parenthesised:

#define GPIO_BANK(gpio, x) (((x) % (gpio)->max_ngpios) >> 5)

> +#define GPIO_OFFSET(x) ((x) & GENMASK(4, 0))
> +#define GPIO_BIT(x, gpio) BIT(GPIO_OFFSET(x % (gpio)->max_ngpios))

Again, put the context parameter first. And again we should add the parentheses around x in the expression.

>
> -static const struct aspeed_sgpio_bank *to_bank(unsigned int offset)
> +static const struct aspeed_sgpio_bank *to_bank(unsigned int offset,
> const struct aspeed_sgpio *gpio)
> {
> unsigned int bank;
>
> - bank = GPIO_BANK(offset);
> + bank = GPIO_BANK(offset, gpio);
>
> WARN_ON(bank >= ARRAY_SIZE(aspeed_sgpio_banks));
> return &aspeed_sgpio_banks[bank];
> @@ -139,18 +151,19 @@ static int aspeed_sgpio_init_valid_mask(struct
> gpio_chip *gc,
> unsigned long *valid_mask, unsigned int ngpios)
> {
> struct aspeed_sgpio *sgpio = gpiochip_get_data(gc);
> + int max_ngpios = sgpio->max_ngpios;
> int n = sgpio->n_sgpio;
> - int c = SGPIO_OUTPUT_OFFSET - n;
> + int c = max_ngpios - n;
>
> - WARN_ON(ngpios < MAX_NR_HW_SGPIO * 2);
> + WARN_ON(ngpios < max_ngpios * 2);
>
> /* input GPIOs in the lower range */
> bitmap_set(valid_mask, 0, n);
> bitmap_clear(valid_mask, n, c);
>
> - /* output GPIOS above SGPIO_OUTPUT_OFFSET */
> - bitmap_set(valid_mask, SGPIO_OUTPUT_OFFSET, n);
> - bitmap_clear(valid_mask, SGPIO_OUTPUT_OFFSET + n, c);
> + /* output GPIOS above max_ngpios */
> + bitmap_set(valid_mask, max_ngpios, n);
> + bitmap_clear(valid_mask, max_ngpios + n, c);
>
> return 0;
> }
> @@ -161,30 +174,30 @@ static void
> aspeed_sgpio_irq_init_valid_mask(struct gpio_chip *gc,
> struct aspeed_sgpio *sgpio = gpiochip_get_data(gc);
> int n = sgpio->n_sgpio;
>
> - WARN_ON(ngpios < MAX_NR_HW_SGPIO * 2);
> + WARN_ON(ngpios < sgpio->max_ngpios * 2);
>
> /* input GPIOs in the lower range */
> bitmap_set(valid_mask, 0, n);
> bitmap_clear(valid_mask, n, ngpios - n);
> }
>
> -static bool aspeed_sgpio_is_input(unsigned int offset)
> +static bool aspeed_sgpio_is_input(unsigned int offset, const struct
> aspeed_sgpio *gpio)
> {
> - return offset < SGPIO_OUTPUT_OFFSET;
> + return offset < gpio->max_ngpios;
> }
>
> static int aspeed_sgpio_get(struct gpio_chip *gc, unsigned int offset)
> {
> struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
> - const struct aspeed_sgpio_bank *bank = to_bank(offset);
> + const struct aspeed_sgpio_bank *bank = to_bank(offset, gpio);
> unsigned long flags;
> enum aspeed_sgpio_reg reg;
> int rc = 0;
>
> spin_lock_irqsave(&gpio->lock, flags);
>
> - reg = aspeed_sgpio_is_input(offset) ? reg_val : reg_rdata;
> - rc = !!(ioread32(bank_reg(gpio, bank, reg)) & GPIO_BIT(offset));
> + reg = aspeed_sgpio_is_input(offset, gpio) ? reg_val : reg_rdata;
> + rc = !!(ioread32(bank_reg(gpio, bank, reg)) & GPIO_BIT(offset, gpio));
>
> spin_unlock_irqrestore(&gpio->lock, flags);
>
> @@ -194,11 +207,11 @@ static int aspeed_sgpio_get(struct gpio_chip *gc,
> unsigned int offset)
> static int sgpio_set_value(struct gpio_chip *gc, unsigned int offset,
> int val)
> {
> struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
> - const struct aspeed_sgpio_bank *bank = to_bank(offset);
> + const struct aspeed_sgpio_bank *bank = to_bank(offset, gpio);
> void __iomem *addr_r, *addr_w;
> u32 reg = 0;
>
> - if (aspeed_sgpio_is_input(offset))
> + if (aspeed_sgpio_is_input(offset, gpio))
> return -EINVAL;
>
> /* Since this is an output, read the cached value from rdata, then
> @@ -209,9 +222,9 @@ static int sgpio_set_value(struct gpio_chip *gc,
> unsigned int offset, int val)
> reg = ioread32(addr_r);
>
> if (val)
> - reg |= GPIO_BIT(offset);
> + reg |= GPIO_BIT(offset, gpio);
> else
> - reg &= ~GPIO_BIT(offset);
> + reg &= ~GPIO_BIT(offset, gpio);
>
> iowrite32(reg, addr_w);
>
> @@ -232,7 +245,9 @@ static void aspeed_sgpio_set(struct gpio_chip *gc,
> unsigned int offset, int val)
>
> static int aspeed_sgpio_dir_in(struct gpio_chip *gc, unsigned int offset)
> {
> - return aspeed_sgpio_is_input(offset) ? 0 : -EINVAL;
> + struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
> +
> + return aspeed_sgpio_is_input(offset, gpio) ? 0 : -EINVAL;
> }
>
> static int aspeed_sgpio_dir_out(struct gpio_chip *gc, unsigned int
> offset, int val)
> @@ -253,7 +268,9 @@ static int aspeed_sgpio_dir_out(struct gpio_chip
> *gc, unsigned int offset, int v
>
> static int aspeed_sgpio_get_direction(struct gpio_chip *gc, unsigned
> int offset)
> {
> - return !!aspeed_sgpio_is_input(offset);
> + struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
> +
> + return !!aspeed_sgpio_is_input(offset, gpio);
> }
>
> static void irqd_to_aspeed_sgpio_data(struct irq_data *d,
> @@ -268,8 +285,8 @@ static void irqd_to_aspeed_sgpio_data(struct irq_data *d,
> WARN_ON(!internal);
>
> *gpio = internal;
> - *bank = to_bank(*offset);
> - *bit = GPIO_BIT(*offset);
> + *bank = to_bank(*offset, internal);
> + *bit = GPIO_BIT(*offset, internal);
> }
>
> static void aspeed_sgpio_irq_ack(struct irq_data *d)
> @@ -466,9 +483,21 @@ static int aspeed_sgpio_setup_irqs(struct
> aspeed_sgpio *gpio,
> return 0;
> }
>
> +static const struct aspeed_sgpio_pdata ast2600_sgpiom_128_pdata = {
> + .max_ngpios = 128,
> + .pin_mask = GENMASK(10, 6),
> +};
> +
> +static const struct aspeed_sgpio_pdata ast2600_sgpiom_80_pdata = {
> + .max_ngpios = 80,
> + .pin_mask = GENMASK(10, 6),
> +};
> +
> static const struct of_device_id aspeed_sgpio_of_table[] = {
> { .compatible = "aspeed,ast2400-sgpio" },
> { .compatible = "aspeed,ast2500-sgpio" },

Add .data for these too.

> + { .compatible = "aspeed,ast2600-sgpiom-128", .data =
> &ast2600_sgpiom_128_pdata, },
> + { .compatible = "aspeed,ast2600-sgpiom-80", .data =
> &ast2600_sgpiom_80_pdata, },
> {}
> };
>
> @@ -476,10 +505,11 @@ MODULE_DEVICE_TABLE(of, aspeed_sgpio_of_table);
>
> static int __init aspeed_sgpio_probe(struct platform_device *pdev)
> {
> + u32 nr_gpios, sgpio_freq, sgpio_clk_div, gpio_cnt_regval, pin_mask;
> + const struct aspeed_sgpio_pdata *pdata;
> struct aspeed_sgpio *gpio;
> - u32 nr_gpios, sgpio_freq, sgpio_clk_div;
> - int rc;
> unsigned long apb_freq;
> + int rc;
>
> gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
> if (!gpio)
> @@ -489,13 +519,26 @@ static int __init aspeed_sgpio_probe(struct
> platform_device *pdev)
> if (IS_ERR(gpio->base))
> return PTR_ERR(gpio->base);
>
> + pdata = device_get_match_data(&pdev->dev);
> + if (pdata) {
> + gpio->max_ngpios = pdata->max_ngpios;
> + pin_mask = pdata->pin_mask;
> + } else {
> + gpio->max_ngpios = MAX_NR_HW_SGPIO;
> + pin_mask = ASPEED_SGPIO_PINS_MASK;

Given the refactor I think the MAX_NR_HW_SGPIO and ASPEED_SGPIO_PINS_MASK macros are confusing and should be dropped.

Further, I think it would be better to just define these 'default' values in .data for the 2400 and 2500 compatibles and drop this if/else entirely.

> + }
> +
> rc = of_property_read_u32(pdev->dev.of_node, "ngpios", &nr_gpios);
> if (rc < 0) {
> dev_err(&pdev->dev, "Could not read ngpios property\n");
> return -EINVAL;
> - } else if (nr_gpios > MAX_NR_HW_SGPIO) {
> + } else if (nr_gpios % 8) {
> + dev_err(&pdev->dev, "Number of GPIOs not multiple of 8: %d\n",
> + nr_gpios);
> + return -EINVAL;
> + } else if (nr_gpios > gpio->max_ngpios) {

I'd prefer this in a separate patch.

> dev_err(&pdev->dev, "Number of GPIOs exceeds the maximum of %d:
> %d\n",
> - MAX_NR_HW_SGPIO, nr_gpios);
> + gpio->max_ngpios, nr_gpios);
> return -EINVAL;
> }
> gpio->n_sgpio = nr_gpios;
> @@ -531,15 +574,14 @@ static int __init aspeed_sgpio_probe(struct
> platform_device *pdev)
> if (sgpio_clk_div > (1 << 16) - 1)
> return -EINVAL;
>
> - iowrite32(FIELD_PREP(ASPEED_SGPIO_CLK_DIV_MASK, sgpio_clk_div) |
> - FIELD_PREP(ASPEED_SGPIO_PINS_MASK, (nr_gpios / 8)) |
> - ASPEED_SGPIO_ENABLE,
> - gpio->base + ASPEED_SGPIO_CTRL);
> + gpio_cnt_regval = ((nr_gpios / 8) << 6) & pin_mask;

Add a #define for the field starting at bit 6.

Andrew