pinctrl/nomadik: support other alternate-C functions

Upgrade nomadik pinctrl driver to enable selection of other
alternate-C[1-4] functions on some specific ux500 SoC pins.
Handling of those functions is done thanks to PRCM GPIOCR
registers. This was previously managed in PRCMU driver and
it was not really convenient. Idea is to provide a common
way to control all alternate functions.

Note that this improvement does not support the old-fashioned way
used to control nomadik pins, namely the "nmk_config_pin()" function
and its derivatives.

Signed-off-by: Jean-Nicolas Graux <jean-nicolas.graux@stericsson.com>
Reviewed-by: Philippe Langlais <philippe.langlais@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 78 insertions, 0 deletions

diff --git a/drivers/pinctrl/pinctrl-nomadik.h b/drivers/pinctrl/pinctrl-nomadik.h
index 5c99f1c62dfd..eef316e979a0 100644
--- a/drivers/pinctrl/pinctrl-nomadik.h
+++ b/drivers/pinctrl/pinctrl-nomadik.h
@@ -8,6 +8,78 @@
 #define PINCTRL_NMK_DB8500	1
 #define PINCTRL_NMK_DB8540	2
 
+#define PRCM_GPIOCR_ALTCX(pin_num,\
+	altc1_used, altc1_ri, altc1_cb,\
+	altc2_used, altc2_ri, altc2_cb,\
+	altc3_used, altc3_ri, altc3_cb,\
+	altc4_used, altc4_ri, altc4_cb)\
+{\
+	.pin = pin_num,\
+	.altcx[PRCM_IDX_GPIOCR_ALTC1] = {\
+		.used = altc1_used,\
+		.reg_index = altc1_ri,\
+		.control_bit = altc1_cb\
+	},\
+	.altcx[PRCM_IDX_GPIOCR_ALTC2] = {\
+		.used = altc2_used,\
+		.reg_index = altc2_ri,\
+		.control_bit = altc2_cb\
+	},\
+	.altcx[PRCM_IDX_GPIOCR_ALTC3] = {\
+		.used = altc3_used,\
+		.reg_index = altc3_ri,\
+		.control_bit = altc3_cb\
+	},\
+	.altcx[PRCM_IDX_GPIOCR_ALTC4] = {\
+		.used = altc4_used,\
+		.reg_index = altc4_ri,\
+		.control_bit = altc4_cb\
+	},\
+}
+
+/**
+ * enum prcm_gpiocr_reg_index
+ * Used to reference an PRCM GPIOCR register address.
+ */
+enum prcm_gpiocr_reg_index {
+	PRCM_IDX_GPIOCR1,
+	PRCM_IDX_GPIOCR2,
+	PRCM_IDX_GPIOCR3
+};
+/**
+ * enum prcm_gpiocr_altcx_index
+ * Used to reference an Other alternate-C function.
+ */
+enum prcm_gpiocr_altcx_index {
+	PRCM_IDX_GPIOCR_ALTC1,
+	PRCM_IDX_GPIOCR_ALTC2,
+	PRCM_IDX_GPIOCR_ALTC3,
+	PRCM_IDX_GPIOCR_ALTC4,
+	PRCM_IDX_GPIOCR_ALTC_MAX,
+};
+
+/**
+ * struct prcm_gpio_altcx - Other alternate-C function
+ * @used: other alternate-C function availability
+ * @reg_index: PRCM GPIOCR register index used to control the function
+ * @control_bit: PRCM GPIOCR bit used to control the function
+ */
+struct prcm_gpiocr_altcx {
+	bool used:1;
+	u8 reg_index:2;
+	u8 control_bit:5;
+} __packed;
+
+/**
+ * struct prcm_gpio_altcx_pin_desc - Other alternate-C pin
+ * @pin: The pin number
+ * @altcx: array of other alternate-C[1-4] functions
+ */
+struct prcm_gpiocr_altcx_pin_desc {
+	unsigned short pin;
+	struct prcm_gpiocr_altcx altcx[PRCM_IDX_GPIOCR_ALTC_MAX];
+};
+
 /**
  * struct nmk_function - Nomadik pinctrl mux function
  * @name: The name of the function, exported to pinctrl core.
@@ -50,6 +122,9 @@ struct nmk_pingroup {
  * @nfunction:	The number of entries in @functions.
  * @groups:	An array describing all pin groups the pin SoC supports.
  * @ngroups:	The number of entries in @groups.
+ * @altcx_pins:	The pins that support Other alternate-C function on this SoC
+ * @npins_altcx: The number of Other alternate-C pins
+ * @prcm_gpiocr_registers: The array of PRCM GPIOCR registers on this SoC
  */
 struct nmk_pinctrl_soc_data {
 	struct pinctrl_gpio_range *gpio_ranges;
@@ -60,6 +135,9 @@ struct nmk_pinctrl_soc_data {
 	unsigned nfunctions;
 	const struct nmk_pingroup *groups;
 	unsigned ngroups;
+	const struct prcm_gpiocr_altcx_pin_desc *altcx_pins;
+	unsigned npins_altcx;
+	const u16 *prcm_gpiocr_registers;
 };
 
 #ifdef CONFIG_PINCTRL_STN8815