Merge branch 'next' into for-linus

Prepare input updates for 6.4 merge window.

1 files changed, 77 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
index 2e0e6432901b..f34a2e59cac7 100644
--- a/drivers/rtc/rtc-abx80x.c
+++ b/drivers/rtc/rtc-abx80x.c
@@ -11,6 +11,7 @@
  */
 
 #include <linux/bcd.h>
+#include <linux/bitfield.h>
 #include <linux/i2c.h>
 #include <linux/kstrtox.h>
 #include <linux/module.h>
@@ -88,6 +89,16 @@
 #define ABX8XX_TRICKLE_STANDARD_DIODE	0x8
 #define ABX8XX_TRICKLE_SCHOTTKY_DIODE	0x4
 
+#define ABX8XX_REG_EXTRAM	0x3f
+#define ABX8XX_EXTRAM_XADS	GENMASK(1, 0)
+
+#define ABX8XX_SRAM_BASE	0x40
+#define ABX8XX_SRAM_WIN_SIZE	0x40
+#define ABX8XX_RAM_SIZE		256
+
+#define NVMEM_ADDR_LOWER	GENMASK(5, 0)
+#define NVMEM_ADDR_UPPER	GENMASK(7, 6)
+
 static u8 trickle_resistors[] = {0, 3, 6, 11};
 
 enum abx80x_chip {AB0801, AB0803, AB0804, AB0805,
@@ -674,6 +685,68 @@ static int abx80x_setup_watchdog(struct abx80x_priv *priv)
 }
 #endif
 
+static int abx80x_nvmem_xfer(struct abx80x_priv *priv, unsigned int offset,
+			     void *val, size_t bytes, bool write)
+{
+	int ret;
+
+	while (bytes) {
+		u8 extram, reg, len, lower, upper;
+
+		lower = FIELD_GET(NVMEM_ADDR_LOWER, offset);
+		upper = FIELD_GET(NVMEM_ADDR_UPPER, offset);
+		extram = FIELD_PREP(ABX8XX_EXTRAM_XADS, upper);
+		reg = ABX8XX_SRAM_BASE + lower;
+		len = min(lower + bytes, (size_t)ABX8XX_SRAM_WIN_SIZE) - lower;
+		len = min_t(u8, len, I2C_SMBUS_BLOCK_MAX);
+
+		ret = i2c_smbus_write_byte_data(priv->client, ABX8XX_REG_EXTRAM,
+						extram);
+		if (ret)
+			return ret;
+
+		if (write)
+			ret = i2c_smbus_write_i2c_block_data(priv->client, reg,
+							     len, val);
+		else
+			ret = i2c_smbus_read_i2c_block_data(priv->client, reg,
+							    len, val);
+		if (ret)
+			return ret;
+
+		offset += len;
+		val += len;
+		bytes -= len;
+	}
+
+	return 0;
+}
+
+static int abx80x_nvmem_read(void *priv, unsigned int offset, void *val,
+			     size_t bytes)
+{
+	return abx80x_nvmem_xfer(priv, offset, val, bytes, false);
+}
+
+static int abx80x_nvmem_write(void *priv, unsigned int offset, void *val,
+			      size_t bytes)
+{
+	return abx80x_nvmem_xfer(priv, offset, val, bytes, true);
+}
+
+static int abx80x_setup_nvmem(struct abx80x_priv *priv)
+{
+	struct nvmem_config config = {
+		.type = NVMEM_TYPE_BATTERY_BACKED,
+		.reg_read = abx80x_nvmem_read,
+		.reg_write = abx80x_nvmem_write,
+		.size = ABX8XX_RAM_SIZE,
+		.priv = priv,
+	};
+
+	return devm_rtc_nvmem_register(priv->rtc, &config);
+}
+
 static const struct i2c_device_id abx80x_id[] = {
 	{ "abx80x", ABX80X },
 	{ "ab0801", AB0801 },
@@ -840,6 +913,10 @@ static int abx80x_probe(struct i2c_client *client)
 			return err;
 	}
 
+	err = abx80x_setup_nvmem(priv);
+	if (err)
+		return err;
+
 	if (client->irq > 0) {
 		dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
 		err = devm_request_threaded_irq(&client->dev, client->irq, NULL,