Hi Maxime


On 12/11/2015 09:25 AM, Maxime Coquelin wrote:

This patch adds pinctrl and GPIO support to STMicroelectronic's STM32
family of MCUs.

While it only supports STM32F429 for now, it has been designed to enable
support of other MCUs of the family (e.g. STM32F746).

Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
---
  drivers/pinctrl/Kconfig                   |    1 +
  drivers/pinctrl/Makefile                  |    1 +
  drivers/pinctrl/stm32/Kconfig             |   16 +
  drivers/pinctrl/stm32/Makefile            |    5 +
  drivers/pinctrl/stm32/pinctrl-stm32.c     |  856 +++++++++++++++
  drivers/pinctrl/stm32/pinctrl-stm32.h     |   43 +
  drivers/pinctrl/stm32/pinctrl-stm32f429.c | 1598 +++++++++++++++++++++++++++++
  7 files changed, 2520 insertions(+)
  create mode 100644 drivers/pinctrl/stm32/Kconfig
  create mode 100644 drivers/pinctrl/stm32/Makefile
  create mode 100644 drivers/pinctrl/stm32/pinctrl-stm32.c
  create mode 100644 drivers/pinctrl/stm32/pinctrl-stm32.h
  create mode 100644 drivers/pinctrl/stm32/pinctrl-stm32f429.c

[...]

+
+static int stm32_pctrl_dt_subnode_to_map(struct pinctrl_dev *pctldev,
+				      struct device_node *node,
+				      struct pinctrl_map **map,
+				      unsigned *reserved_maps,
+				      unsigned *num_maps)
+{
+	struct stm32_pinctrl *pctl;
+	struct stm32_pinctrl_group *grp;
+	struct property *pins;
+	u32 pinfunc, pin, func;
+	unsigned long *configs;
+	unsigned int num_configs;
+	bool has_config = 0;
+	unsigned reserve = 0;
+	int num_pins, num_funcs, maps_per_pin, i, err;
+
+	pctl = pinctrl_dev_get_drvdata(pctldev);
+
+	pins = of_find_property(node, "pinmux", NULL);
+	if (!pins) {
+		dev_err(pctl->dev, "missing pins property in node %s .\n",
+				node->name);
+		return -EINVAL;
+	}
+
+	err = pinconf_generic_parse_dt_config(node, pctldev, &configs,
+		&num_configs);
+	if (num_configs)
+		has_config = 1;
+
+	num_pins = pins->length / sizeof(u32);
+	num_funcs = num_pins;
+	maps_per_pin = 0;
+	if (num_funcs)
+		maps_per_pin++;
+	if (has_config && num_pins >= 1)
+		maps_per_pin++;
+
+	if (!num_pins || !maps_per_pin)
+		return -EINVAL;
+
+	reserve = num_pins * maps_per_pin;
+
+	err = pinctrl_utils_reserve_map(pctldev, map,
+			reserved_maps, num_maps, reserve);
+	if (err < 0)
+		goto fail;
+
+	for (i = 0; i < num_pins; i++) {
+		err = of_property_read_u32_index(node, "pinmux",
+				i, &pinfunc);
+		if (err)
+			goto fail;

as a "goto fail" doesn't do more than a return, here do directly "return 
err;"

+
+		pin = STM32_GET_PIN_NO(pinfunc);
+		func = STM32_GET_PIN_FUNC(pinfunc);
+
+		if (pin >= pctl->match_data->npins) {
+			dev_err(pctl->dev, "invalid pin number.\n");
+			err = -EINVAL;
+			goto fail;

ditto, return -EINVAL

+		}
+
+		if (!stm32_pctrl_is_function_valid(pctl, pin, func)) {
+			dev_err(pctl->dev, "invalid function.\n");
+			err = -EINVAL;
+			goto fail;

ditto

+		}
+
+		grp = stm32_pctrl_find_group_by_pin(pctl, pin);
+		if (!grp) {
+			dev_err(pctl->dev, "unable to match pin %d to group\n",
+					pin);
+			return -EINVAL;
+		}
+
+		err = stm32_pctrl_dt_node_to_map_func(pctl, pin, func, grp, map,
+				reserved_maps, num_maps);
+		if (err < 0)
+			goto fail;

ditto

+
+		if (has_config) {
+			err = pinctrl_utils_add_map_configs(pctldev, map,
+					reserved_maps, num_maps, grp->name,
+					configs, num_configs,
+					PIN_MAP_TYPE_CONFIGS_GROUP);
+			if (err < 0)
+				goto fail;

ditto

+		}
+	}
+
+	return 0;
+
+fail:
+	return err;
+}
+

[...]

+
+static int stm32_pmx_set_mux(struct pinctrl_dev *pctldev,
+			    unsigned function,
+			    unsigned group)
+{
+	bool ret;
+	const struct stm32_desc_function *desc;
+	struct stm32_pinctrl *pctl = pinctrl_dev_get_drvdata(pctldev);
+	struct stm32_pinctrl_group *g = pctl->groups + group;
+	struct pinctrl_gpio_range *range;
+	struct stm32_gpio_bank *bank;
+	u32 mode, alt;
+	int pin;
+
+	ret = stm32_pctrl_is_function_valid(pctl, g->pin, function);
+	if (!ret) {
+		dev_err(pctl->dev, "invalid function %d on group %d .\n",
+				function, group);
+		return -EINVAL;
+	}
+
+	desc = stm32_pctrl_find_function_by_pin(pctl, g->pin, function);
+	if (!desc)
+		return -EINVAL;

stm32_pctrl_find_function_by_pin() is useless, desc is never used

stm32_pctrl_is_function_valid(), above, already checks that function exists for the requested pins

+
+	range = pinctrl_find_gpio_range_from_pin(pctldev, g->pin);
+	bank = gpio_range_to_bank(range);
+	pin = stm32_gpio_pin(g->pin);
+
+	mode = stm32_gpio_get_mode(function);
+	alt = stm32_gpio_get_alt(function);
+
+	stm32_pmx_set_mode(bank, pin, mode, alt);
+
+	return 0;
+}
+