Re: [net-next PATCH v2 5/9] net: dsa: qca8k: convert qca8k to regmap helper

Convert any qca8k read/write/rmw/set/clear/pool to regmap helper and add
missing config to regmap_config struct.
Ipq40xx SoC have the internal switch based on the qca8k regmap but use
mmio for read/write/rmw operation instead of mdio.
In preparation for the support of this internal switch, convert the
driver to regmap API to later split the driver to common and specific
code. The overhead introduced by the use of regamp API is marginal as the
internal mdio will bypass it by using its direct access and regmap will be
used only by configuration functions or fdb access.

Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
---
 drivers/net/dsa/qca8k.c | 289 ++++++++++++++++++----------------------
 1 file changed, 131 insertions(+), 158 deletions(-)

diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c
index 52fca800e6f7..159a1065e66b 100644
--- a/drivers/net/dsa/qca8k.c
+++ b/drivers/net/dsa/qca8k.c

@@ -10,6 +10,7 @@
 #include <linux/phy.h>
 #include <linux/netdevice.h>
 #include <linux/bitfield.h>
+#include <linux/regmap.h>
 #include <net/dsa.h>
 #include <linux/of_net.h>
 #include <linux/of_mdio.h>

@@ -150,8 +151,9 @@ qca8k_set_page(struct mii_bus *bus, u16 page)
 }
 
 static int
-qca8k_read(struct qca8k_priv *priv, u32 reg, u32 *val)
+qca8k_regmap_read(void *ctx, uint32_t reg, uint32_t *val)
 {
+	struct qca8k_priv *priv = (struct qca8k_priv *)ctx;
 	struct mii_bus *bus = priv->bus;
 	u16 r1, r2, page;
 	int ret;

@@ -172,8 +174,9 @@ qca8k_read(struct qca8k_priv *priv, u32 reg, u32 *val)
 }
 
 static int
-qca8k_write(struct qca8k_priv *priv, u32 reg, u32 val)
+qca8k_regmap_write(void *ctx, uint32_t reg, uint32_t val)
 {
+	struct qca8k_priv *priv = (struct qca8k_priv *)ctx;
 	struct mii_bus *bus = priv->bus;
 	u16 r1, r2, page;
 	int ret;

@@ -194,8 +197,9 @@ qca8k_write(struct qca8k_priv *priv, u32 reg, u32 val)
 }
 
 static int
-qca8k_rmw(struct qca8k_priv *priv, u32 reg, u32 mask, u32 write_val)
+qca8k_regmap_update_bits(void *ctx, uint32_t reg, uint32_t mask, uint32_t write_val)
 {
+	struct qca8k_priv *priv = (struct qca8k_priv *)ctx;
 	struct mii_bus *bus = priv->bus;
 	u16 r1, r2, page;
 	u32 val;

@@ -223,34 +227,6 @@ qca8k_rmw(struct qca8k_priv *priv, u32 reg, u32 mask, u32 write_val)
 	return ret;
 }
 
-static int
-qca8k_reg_set(struct qca8k_priv *priv, u32 reg, u32 val)
-{
-	return qca8k_rmw(priv, reg, 0, val);
-}
-
-static int
-qca8k_reg_clear(struct qca8k_priv *priv, u32 reg, u32 val)
-{
-	return qca8k_rmw(priv, reg, val, 0);
-}
-
-static int
-qca8k_regmap_read(void *ctx, uint32_t reg, uint32_t *val)
-{
-	struct qca8k_priv *priv = (struct qca8k_priv *)ctx;
-
-	return qca8k_read(priv, reg, val);
-}
-
-static int
-qca8k_regmap_write(void *ctx, uint32_t reg, uint32_t val)
-{
-	struct qca8k_priv *priv = (struct qca8k_priv *)ctx;
-
-	return qca8k_write(priv, reg, val);
-}
-
 static const struct regmap_range qca8k_readable_ranges[] = {
 	regmap_reg_range(0x0000, 0x00e4), /* Global control */
 	regmap_reg_range(0x0100, 0x0168), /* EEE control */

@@ -282,26 +258,19 @@ static struct regmap_config qca8k_regmap_config = {
 	.max_register = 0x16ac, /* end MIB - Port6 range */
 	.reg_read = qca8k_regmap_read,
 	.reg_write = qca8k_regmap_write,
+	.reg_update_bits = qca8k_regmap_update_bits,
 	.rd_table = &qca8k_readable_table,
+	.disable_locking = true, /* Locking is handled by qca8k read/write */
+	.cache_type = REGCACHE_NONE, /* Explicitly disable CACHE */
 };
 
 static int
 qca8k_busy_wait(struct qca8k_priv *priv, u32 reg, u32 mask)
 {
-	int ret, ret1;
 	u32 val;
 
-	ret = read_poll_timeout(qca8k_read, ret1, !(val & mask),
-				0, QCA8K_BUSY_WAIT_TIMEOUT * USEC_PER_MSEC, false,
-				priv, reg, &val);
-
-	/* Check if qca8k_read has failed for a different reason
-	 * before returning -ETIMEDOUT
-	 */
-	if (ret < 0 && ret1 < 0)
-		return ret1;
-
-	return ret;
+	return regmap_read_poll_timeout(priv->regmap, reg, val, !(val & mask), 0,
+				       QCA8K_BUSY_WAIT_TIMEOUT * USEC_PER_MSEC);
 }
 
 static int

@@ -312,7 +281,7 @@ qca8k_fdb_read(struct qca8k_priv *priv, struct qca8k_fdb *fdb)
 
 	/* load the ARL table into an array */
 	for (i = 0; i < 4; i++) {
-		ret = qca8k_read(priv, QCA8K_REG_ATU_DATA0 + (i * 4), &val);
+		ret = regmap_read(priv->regmap, QCA8K_REG_ATU_DATA0 + (i * 4), &val);