pinctrl: bcm2835: Add support for BCM2711 pull-up functionality

The BCM2711 has a new way of selecting the pull-up/pull-down setting
for a GPIO pin. The registers used for the BCM2835, GP_PUD and
GP_PUDCLKn0, are no longer connected. A new set of registers,
GP_GPIO_PUP_PDN_CNTRL_REGx must be used. This commit will add
a new compatible string "brcm,bcm2711-gpio" and the kernel
driver will use it to select which method is used to select
pull-up/pull-down.

This patch based on a patch by Al Cooper which was intended for the
BCM7211. This is a bugfixed and improved version.

Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://lore.kernel.org/r/1563776607-8368-3-git-send-email-wahrenst@gmx.net
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/pinctrl/bcm/pinctrl-bcm2835.c b/drivers/pinctrl/bcm/pinctrl-bcm2835.c
index 183d1ffe6a75de6f6f205c17b88bc15db4fd23a8..a493205bedaf1a8922d2ceca99bcddb87e98cd38 100644 (file)
--- a/drivers/pinctrl/bcm/pinctrl-bcm2835.c
+++ b/drivers/pinctrl/bcm/pinctrl-bcm2835.c
@@ -57,15 +57,24 @@
 #define GPAFEN0                0x88    /* Pin Async Falling Edge Detect */
 #define GPPUD          0x94    /* Pin Pull-up/down Enable */
 #define GPPUDCLK0      0x98    /* Pin Pull-up/down Enable Clock */
+#define GP_GPIO_PUP_PDN_CNTRL_REG0 0xe4 /* 2711 Pin Pull-up/down select */
 
 #define FSEL_REG(p)            (GPFSEL0 + (((p) / 10) * 4))
 #define FSEL_SHIFT(p)          (((p) % 10) * 3)
 #define GPIO_REG_OFFSET(p)     ((p) / 32)
 #define GPIO_REG_SHIFT(p)      ((p) % 32)
 
+#define PUD_2711_MASK          0x3
+#define PUD_2711_REG_OFFSET(p) ((p) / 16)
+#define PUD_2711_REG_SHIFT(p)  (((p) % 16) * 2)
+
 /* argument: bcm2835_pinconf_pull */
 #define BCM2835_PINCONF_PARAM_PULL     (PIN_CONFIG_END + 1)
 
+#define BCM2711_PULL_NONE      0x0
+#define BCM2711_PULL_UP                0x1
+#define BCM2711_PULL_DOWN      0x2
+
 struct bcm2835_pinctrl {
        struct device *dev;
        void __iomem *base;
@@ -975,6 +984,77 @@ static const struct pinconf_ops bcm2835_pinconf_ops = {
        .pin_config_set = bcm2835_pinconf_set,
 };
 
+static void bcm2711_pull_config_set(struct bcm2835_pinctrl *pc,
+                                   unsigned int pin, unsigned int arg)
+{
+       u32 shifter;
+       u32 value;
+       u32 off;
+
+       off = PUD_2711_REG_OFFSET(pin);
+       shifter = PUD_2711_REG_SHIFT(pin);
+
+       value = bcm2835_gpio_rd(pc, GP_GPIO_PUP_PDN_CNTRL_REG0 + (off * 4));
+       value &= ~(PUD_2711_MASK << shifter);
+       value |= (arg << shifter);
+       bcm2835_gpio_wr(pc, GP_GPIO_PUP_PDN_CNTRL_REG0 + (off * 4), value);
+}
+
+static int bcm2711_pinconf_set(struct pinctrl_dev *pctldev,
+                              unsigned int pin, unsigned long *configs,
+                              unsigned int num_configs)
+{
+       struct bcm2835_pinctrl *pc = pinctrl_dev_get_drvdata(pctldev);
+       u32 param, arg;
+       int i;
+
+       for (i = 0; i < num_configs; i++) {
+               param = pinconf_to_config_param(configs[i]);
+               arg = pinconf_to_config_argument(configs[i]);
+
+               switch (param) {
+               /* convert legacy brcm,pull */
+               case BCM2835_PINCONF_PARAM_PULL:
+                       if (arg == BCM2835_PUD_UP)
+                               arg = BCM2711_PULL_UP;
+                       else if (arg == BCM2835_PUD_DOWN)
+                               arg = BCM2711_PULL_DOWN;
+                       else
+                               arg = BCM2711_PULL_NONE;
+
+                       bcm2711_pull_config_set(pc, pin, arg);
+                       break;
+
+               /* Set pull generic bindings */
+               case PIN_CONFIG_BIAS_DISABLE:
+                       bcm2711_pull_config_set(pc, pin, BCM2711_PULL_NONE);
+                       break;
+               case PIN_CONFIG_BIAS_PULL_DOWN:
+                       bcm2711_pull_config_set(pc, pin, BCM2711_PULL_DOWN);
+                       break;
+               case PIN_CONFIG_BIAS_PULL_UP:
+                       bcm2711_pull_config_set(pc, pin, BCM2711_PULL_UP);
+                       break;
+
+               /* Set output-high or output-low */
+               case PIN_CONFIG_OUTPUT:
+                       bcm2835_gpio_set_bit(pc, arg ? GPSET0 : GPCLR0, pin);
+                       break;
+
+               default:
+                       return -ENOTSUPP;
+               }
+       } /* for each config */
+
+       return 0;
+}
+
+static const struct pinconf_ops bcm2711_pinconf_ops = {
+       .is_generic = true,
+       .pin_config_get = bcm2835_pinconf_get,
+       .pin_config_set = bcm2711_pinconf_set,
+};
+
 static struct pinctrl_desc bcm2835_pinctrl_desc = {
        .name = MODULE_NAME,
        .pins = bcm2835_gpio_pins,
@@ -990,6 +1070,18 @@ static struct pinctrl_gpio_range bcm2835_pinctrl_gpio_range = {
        .npins = BCM2835_NUM_GPIOS,
 };
 
+static const struct of_device_id bcm2835_pinctrl_match[] = {
+       {
+               .compatible = "brcm,bcm2835-gpio",
+               .data = &bcm2835_pinconf_ops,
+       },
+       {
+               .compatible = "brcm,bcm2711-gpio",
+               .data = &bcm2711_pinconf_ops,
+       },
+       {}
+};
+
 static int bcm2835_pinctrl_probe(struct platform_device *pdev)
 {
        struct device *dev = &pdev->dev;
@@ -997,6 +1089,8 @@ static int bcm2835_pinctrl_probe(struct platform_device *pdev)
        struct bcm2835_pinctrl *pc;
        struct resource iomem;
        int err, i;
+       const struct of_device_id *match;
+
        BUILD_BUG_ON(ARRAY_SIZE(bcm2835_gpio_pins) != BCM2835_NUM_GPIOS);
        BUILD_BUG_ON(ARRAY_SIZE(bcm2835_gpio_groups) != BCM2835_NUM_GPIOS);
 
@@ -1073,6 +1167,12 @@ static int bcm2835_pinctrl_probe(struct platform_device *pdev)
                                             bcm2835_gpio_irq_handler);
        }
 
+       match = of_match_node(bcm2835_pinctrl_match, pdev->dev.of_node);
+       if (match) {
+               bcm2835_pinctrl_desc.confops =
+                       (const struct pinconf_ops *)match->data;
+       }
+
        pc->pctl_dev = devm_pinctrl_register(dev, &bcm2835_pinctrl_desc, pc);
        if (IS_ERR(pc->pctl_dev)) {
                gpiochip_remove(&pc->gpio_chip);
@@ -1087,11 +1187,6 @@ static int bcm2835_pinctrl_probe(struct platform_device *pdev)
        return 0;
 }
 
-static const struct of_device_id bcm2835_pinctrl_match[] = {
-       { .compatible = "brcm,bcm2835-gpio" },
-       {}
-};
-
 static struct platform_driver bcm2835_pinctrl_driver = {
        .probe = bcm2835_pinctrl_probe,
        .driver = {