pinctrl: aspeed: Split out pinmux from general pinctrl

ASPEED have completely rearranged the System Control Unit register
layout with the AST2600. The existing code took advantage of the fact
that the AST2400 and AST2500 had layouts that were similar enough to
have little impact on the pinmux infrastructure (though there is a wart
with read-modify-write vs write-1-clear semantics of the hardware
strapping registers between the two).

Given that any similarity has been thrown out with the AST2600, separate
out the function applying an expression state to be driver-specific.
With it, extract out the pinmux macro jungle to its own header and
implementation so the pieces can be composed without dependency cycles.

Cc: Johnny Huang <johnny_huang@aspeedtech.com>
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Link: https://lore.kernel.org/r/20190628023838.15426-8-andrew@aj.id.au
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 90 insertions, 4 deletions

diff --git a/drivers/pinctrl/aspeed/pinctrl-aspeed-g4.c b/drivers/pinctrl/aspeed/pinctrl-aspeed-g4.c
index 05b153034517..37f325fb5d7c 100644
--- a/drivers/pinctrl/aspeed/pinctrl-aspeed-g4.c
+++ b/drivers/pinctrl/aspeed/pinctrl-aspeed-g4.c
@@ -22,9 +22,35 @@
 
 #include "../core.h"
 #include "../pinctrl-utils.h"
+#include "pinmux-aspeed.h"
 #include "pinctrl-aspeed.h"
 
 /*
+ * The "Multi-function Pins Mapping and Control" table in the SoC datasheet
+ * references registers by the device/offset mnemonic. The register macros
+ * below are named the same way to ease transcription and verification (as
+ * opposed to naming them e.g. PINMUX_CTRL_[0-9]). Further, signal expressions
+ * reference registers beyond those dedicated to pinmux, such as the system
+ * reset control and MAC clock configuration registers.
+ */
+#define SCU2C           0x2C /* Misc. Control Register */
+#define SCU3C           0x3C /* System Reset Control/Status Register */
+#define SCU48           0x48 /* MAC Interface Clock Delay Setting */
+#define HW_STRAP1       0x70 /* AST2400 strapping is 33 bits, is split */
+#define HW_REVISION_ID  0x7C /* Silicon revision ID register */
+#define SCU80           0x80 /* Multi-function Pin Control #1 */
+#define SCU84           0x84 /* Multi-function Pin Control #2 */
+#define SCU88           0x88 /* Multi-function Pin Control #3 */
+#define SCU8C           0x8C /* Multi-function Pin Control #4 */
+#define SCU90           0x90 /* Multi-function Pin Control #5 */
+#define SCU94           0x94 /* Multi-function Pin Control #6 */
+#define SCUA0           0xA0 /* Multi-function Pin Control #7 */
+#define SCUA4           0xA4 /* Multi-function Pin Control #8 */
+#define SCUA8           0xA8 /* Multi-function Pin Control #9 */
+#define SCUAC           0xAC /* Multi-function Pin Control #10 */
+#define HW_STRAP2       0xD0 /* Strapping */
+
+/*
  * Uses undefined macros for symbol naming and references, eg GPIOA0, MAC1LINK,
  * TIMER3 etc.
  *
@@ -2390,13 +2416,73 @@ static const struct aspeed_pin_config aspeed_g4_configs[] = {
 	{ PIN_CONFIG_INPUT_DEBOUNCE, { C14, B14 }, SCUA8, 27 },
 };
 
+static int aspeed_g4_sig_expr_set(const struct aspeed_pinmux_data *ctx,
+				  const struct aspeed_sig_expr *expr,
+				  bool enable)
+{
+	int ret;
+	int i;
+
+	for (i = 0; i < expr->ndescs; i++) {
+		const struct aspeed_sig_desc *desc = &expr->descs[i];
+		u32 pattern = enable ? desc->enable : desc->disable;
+		u32 val = (pattern << __ffs(desc->mask));
+
+		if (!ctx->maps[desc->ip])
+			return -ENODEV;
+
+		/*
+		 * Strap registers are configured in hardware or by early-boot
+		 * firmware. Treat them as read-only despite that we can write
+		 * them. This may mean that certain functions cannot be
+		 * deconfigured and is the reason we re-evaluate after writing
+		 * all descriptor bits.
+		 *
+		 * Port D and port E GPIO loopback modes are the only exception
+		 * as those are commonly used with front-panel buttons to allow
+		 * normal operation of the host when the BMC is powered off or
+		 * fails to boot. Once the BMC has booted, the loopback mode
+		 * must be disabled for the BMC to control host power-on and
+		 * reset.
+		 */
+		if (desc->ip == ASPEED_IP_SCU && desc->reg == HW_STRAP1 &&
+		    !(desc->mask & (BIT(21) | BIT(22))))
+			continue;
+
+		if (desc->ip == ASPEED_IP_SCU && desc->reg == HW_STRAP2)
+			continue;
+
+		ret = regmap_update_bits(ctx->maps[desc->ip], desc->reg,
+					 desc->mask, val);
+
+		if (ret)
+			return ret;
+	}
+
+	ret = aspeed_sig_expr_eval(ctx, expr, enable);
+	if (ret < 0)
+		return ret;
+
+	if (!ret)
+		return -EPERM;
+
+	return 0;
+}
+
+static const struct aspeed_pinmux_ops aspeed_g4_ops = {
+	.set = aspeed_g4_sig_expr_set,
+};
+
 static struct aspeed_pinctrl_data aspeed_g4_pinctrl_data = {
 	.pins = aspeed_g4_pins,
 	.npins = ARRAY_SIZE(aspeed_g4_pins),
-	.groups = aspeed_g4_groups,
-	.ngroups = ARRAY_SIZE(aspeed_g4_groups),
-	.functions = aspeed_g4_functions,
-	.nfunctions = ARRAY_SIZE(aspeed_g4_functions),
+	.pinmux = {
+		.ops = &aspeed_g4_ops,
+		.groups = aspeed_g4_groups,
+		.ngroups = ARRAY_SIZE(aspeed_g4_groups),
+		.functions = aspeed_g4_functions,
+		.nfunctions = ARRAY_SIZE(aspeed_g4_functions),
+	},
 	.configs = aspeed_g4_configs,
 	.nconfigs = ARRAY_SIZE(aspeed_g4_configs),
 };