pinctrl: meson: support amlogic S6/S7/S7D SoC

In some Amlogic SoCs, to save register space or due to some
abnormal arrangements, two sets of pins share one mux register.

A group starting from pin0 is the main pin group, which acquires
the register address through DTS and has management permissions,
but the register bit offset is undetermined.

Another GPIO group as a subordinate group. Some pins mux use share
register and bit offset from bit0 . But this group do not have
register management permissions.

This submission implements this situation.

Signed-off-by: Xianwei Zhao <[e-mail]>
Link: https://lore.kernel.org/[e-mail]
Signed-off-by: Linus Walleij <[e-mail]>

drivers/pinctrl/meson/pinctrl-amlogic-a4.c

···
 	u32 bit_offset[AML_NUM_REG];
 };
 
+/*
+ * partial bank(subordinate) pins mux config use other bank(main) mux registgers
+ * m_bank_id:	the main bank which pin_id from 0, but register bit not from bit 0
+ * m_bit_offs:	bit offset the main bank mux register
+ * sid:         start pin_id of subordinate bank
+ * eid:         end pin_id of subordinate bank
+ */
+struct multi_mux {
+	unsigned int m_bank_id;
+	unsigned int m_bit_offs;
+	unsigned int sid;
+	unsigned int eid;
+};
+
 struct aml_pctl_data {
 	unsigned int number;
+	const struct multi_mux *p_mux;
 };
 
 struct aml_pmx_func {
···
 	struct gpio_chip		gpio_chip;
 	struct aml_pio_control		pc;
 	u32				bank_id;
+	u32				mux_bit_offs;
 	unsigned int			pin_base;
 	struct regmap			*reg_mux;
 	struct regmap			*reg_gpio;
 	struct regmap			*reg_ds;
+	const struct multi_mux		*p_mux;
 };
 
 struct aml_pinctrl {
···
 "GPIOCC", "TEST_N", "ANALOG"
 };
 
+const struct multi_mux multi_mux_s7[] = {
+	{
+		.m_bank_id = AMLOGIC_GPIO_CC,
+		.m_bit_offs = 24,
+		.sid = (AMLOGIC_GPIO_X << 8) + 16,
+		.eid = (AMLOGIC_GPIO_X << 8) + 19,
+	},
+};
+
+const struct aml_pctl_data s7_priv_data = {
+	.number = ARRAY_SIZE(multi_mux_s7),
+	.p_mux = multi_mux_s7,
+};
+
+const struct multi_mux multi_mux_s6[] = {
+	{
+		.m_bank_id = AMLOGIC_GPIO_CC,
+		.m_bit_offs = 24,
+		.sid = (AMLOGIC_GPIO_X << 8) + 16,
+		.eid = (AMLOGIC_GPIO_X << 8) + 19,
+	}, {
+		.m_bank_id = AMLOGIC_GPIO_F,
+		.m_bit_offs = 4,
+		.sid = (AMLOGIC_GPIO_D << 8) + 6,
+		.eid = (AMLOGIC_GPIO_D << 8) + 6,
+	},
+};
+
+const struct aml_pctl_data s6_priv_data = {
+	.number = ARRAY_SIZE(multi_mux_s6),
+	.p_mux = multi_mux_s6,
+};
+
 static int aml_pmx_calc_reg_and_offset(struct pinctrl_gpio_range *range,
 				       unsigned int pin, unsigned int *reg,
 				       unsigned int *offset)
 {
 	unsigned int shift;
 
-	shift = (pin - range->pin_base) << 2;
+	shift = ((pin - range->pin_base) << 2) + *offset;
 	*reg = (shift / 32) * 4;
 	*offset = shift % 32;
 
···
 				 int pin_id, int func)
 {
 	struct aml_gpio_bank *bank = gpio_chip_to_bank(range->gc);
+	unsigned int shift;
 	int reg;
-	int offset;
+	int i;
+	unsigned int offset = bank->mux_bit_offs;
+	const struct multi_mux *p_mux;
 
+	/* peculiar mux reg set */
+	if (bank->p_mux) {
+		p_mux = bank->p_mux;
+		if (pin_id >= p_mux->sid && pin_id <= p_mux->eid) {
+			bank = NULL;
+			for (i = 0; i < info->nbanks; i++) {
+				if (info->banks[i].bank_id == p_mux->m_bank_id) {
+					bank = &info->banks[i];
+						break;
+				}
+			}
+
+			if (!bank || !bank->reg_mux)
+				return -EINVAL;
+
+			shift = (pin_id - p_mux->sid) << 2;
+			reg = (shift / 32) * 4;
+			offset = shift % 32;
+			return regmap_update_bits(bank->reg_mux, reg,
+					0xf << offset, (func & 0xf) << offset);
+		}
+	}
+
+	/* normal mux reg set */
 	if (!bank->reg_mux)
 		return 0;
 
···
 static void init_bank_register_bit(struct aml_pinctrl *info,
 				   struct aml_gpio_bank *bank)
 {
+	const struct aml_pctl_data *data = info->data;
+	const struct multi_mux *p_mux;
 	int i;
 
 	for (i = 0; i < AML_NUM_REG; i++) {
 		bank->pc.reg_offset[i] = aml_def_regoffs[i];
 		bank->pc.bit_offset[i] = 0;
+	}
+
+	bank->mux_bit_offs = 0;
+
+	if (data) {
+		for (i = 0; i < data->number; i++) {
+			p_mux = &data->p_mux[i];
+			if (bank->bank_id == p_mux->m_bank_id) {
+				bank->mux_bit_offs = p_mux->m_bit_offs;
+				break;
+			}
+			if (p_mux->sid >> 8 == bank->bank_id) {
+				bank->p_mux = p_mux;
+				break;
+			}
+		}
 	}
 }
 
···
 
 static const struct of_device_id aml_pctl_of_match[] = {
 	{ .compatible = "amlogic,pinctrl-a4", },
+	{ .compatible = "amlogic,pinctrl-s7", .data = &s7_priv_data, },
+	{ .compatible = "amlogic,pinctrl-s6", .data = &s6_priv_data, },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, aml_pctl_dt_match);