pinctrl: aspeed: Read and write bits in LPC and GFX controllers

The System Control Unit IP block in the Aspeed SoCs is typically where
the pinmux configuration is found, but not always. A number of pins
depend on state in one of LPC Host Control (LHC) or SoC Display
Controller (GFX) IP blocks, so the Aspeed pinmux drivers should have the
means to adjust these as necessary.

We use syscon to cast a regmap over the GFX and LPC blocks, which is
used as an arbitration layer between the relevant driver and the pinctrl
subsystem. The regmaps are then exposed to the SoC-specific pinctrl
drivers by phandles in the devicetree, and are selected during a mux
request by querying a new 'ip' member in struct aspeed_sig_desc.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 23 insertions, 9 deletions

diff --git a/drivers/pinctrl/aspeed/pinctrl-aspeed.h b/drivers/pinctrl/aspeed/pinctrl-aspeed.h
index 3e72ef8c54bf..0e93cbf2ff33 100644
--- a/drivers/pinctrl/aspeed/pinctrl-aspeed.h
+++ b/drivers/pinctrl/aspeed/pinctrl-aspeed.h
@@ -232,6 +232,11 @@
  * group.
  */
 
+#define ASPEED_IP_SCU		0
+#define ASPEED_IP_GFX		1
+#define ASPEED_IP_LPC		2
+#define ASPEED_NR_PINMUX_IPS	3
+
 /*
  * The "Multi-function Pins Mapping and Control" table in the SoC datasheet
  * references registers by the device/offset mnemonic. The register macros
@@ -261,7 +266,9 @@
   * A signal descriptor, which describes the register, bits and the
   * enable/disable values that should be compared or written.
   *
-  * @reg: The register offset from base in bytes
+  * @ip: The IP block identifier, used as an index into the regmap array in
+  *      struct aspeed_pinctrl_data
+  * @reg: The register offset with respect to the base address of the IP block
   * @mask: The mask to apply to the register. The lowest set bit of the mask is
   *        used to derive the shift value.
   * @enable: The value that enables the function. Value should be in the LSBs,
@@ -270,6 +277,7 @@
   *           LSBs, not at the position of the mask.
   */
 struct aspeed_sig_desc {
+	unsigned int ip;
 	unsigned int reg;
 	u32 mask;
 	u32 enable;
@@ -313,24 +321,30 @@ struct aspeed_pin_desc {
 
 /* Macro hell */
 
+#define SIG_DESC_IP_BIT(ip, reg, idx, val) \
+	{ ip, reg, BIT_MASK(idx), val, (((val) + 1) & 1) }
+
 /**
- * Short-hand macro for describing a configuration enabled by the state of one
- * bit. The disable value is derived.
+ * Short-hand macro for describing an SCU descriptor enabled by the state of
+ * one bit. The disable value is derived.
  *
  * @reg: The signal's associated register, offset from base
  * @idx: The signal's bit index in the register
  * @val: The value (0 or 1) that enables the function
  */
 #define SIG_DESC_BIT(reg, idx, val) \
-	{ reg, BIT_MASK(idx), val, (((val) + 1) & 1) }
+	SIG_DESC_IP_BIT(ASPEED_IP_SCU, reg, idx, val)
+
+#define SIG_DESC_IP_SET(ip, reg, idx) SIG_DESC_IP_BIT(ip, reg, idx, 1)
 
 /**
- * A further short-hand macro describing a configuration enabled with a set bit.
+ * A further short-hand macro expanding to an SCU descriptor enabled by a set
+ * bit.
  *
- * @reg: The configuration's associated register, offset from base
- * @idx: The configuration's bit index in the register
+ * @reg: The register, offset from base
+ * @idx: The bit index in the register
  */
-#define SIG_DESC_SET(reg, idx) SIG_DESC_BIT(reg, idx, 1)
+#define SIG_DESC_SET(reg, idx) SIG_DESC_IP_BIT(ASPEED_IP_SCU, reg, idx, 1)
 
 #define SIG_DESC_LIST_SYM(sig, func) sig_descs_ ## sig ## _ ## func
 #define SIG_DESC_LIST_DECL(sig, func, ...) \
@@ -500,7 +514,7 @@ struct aspeed_pin_desc {
 	MS_PIN_DECL_(pin, SIG_EXPR_LIST_PTR(gpio))
 
 struct aspeed_pinctrl_data {
-	struct regmap *map;
+	struct regmap *maps[ASPEED_NR_PINMUX_IPS];
 
 	const struct pinctrl_pin_desc *pins;
 	const unsigned int npins;