Merge branch 'i2c/for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang:
 "I2C has quite some patches for you this time. I hope it is the move to
  per-driver-maintainers which is now showing results. We will see.

  The big news is two new drivers (Nuvoton NPCM and Qualcomm CCI),
  larger refactoring of the Designware, Tegra, and PXA drivers, the
  Cadence driver supports being a slave now, and there is support to
  instanciate SPD eeproms for well-known cases (which will be
  user-visible because the i801 driver supports it), and some
  devm_platform_ioremap_resource() conversions which blow up the
  diffstat.

  Note that I applied the Nuvoton driver quite late, so some minor fixup
  patches arrived during the merge window. I chose to apply them right
  away because they were trivial"

* 'i2c/for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (109 commits)
  i2c: Drop stray comma in MODULE_AUTHOR statements
  i2c: npcm7xx: npcm_i2caddr[] can be static
  MAINTAINERS: npcm7xx: Add maintainer for Nuvoton NPCM BMC
  i2c: npcm7xx: Fix a couple of error codes in probe
  i2c: icy: Fix build with CONFIG_AMIGA_PCMCIA=n
  i2c: npcm7xx: Remove unnecessary parentheses
  i2c: npcm7xx: Add support for slave mode for Nuvoton
  i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver
  dt-bindings: i2c: npcm7xx: add NPCM I2C controller
  i2c: pxa: don't error out if there's no pinctrl
  i2c: add 'single-master' property to generic bindings
  i2c: designware: Add Baikal-T1 System I2C support
  i2c: designware: Move reg-space remapping into a dedicated function
  i2c: designware: Retrieve quirk flags as early as possible
  i2c: designware: Convert driver to using regmap API
  i2c: designware: Discard Cherry Trail model flag
  i2c: designware: Add Baytrail sem config DW I2C platform dependency
  i2c: designware: slave: Set DW I2C core module dependency
  i2c: designware: Use `-y` to build multi-object modules
  dt-bindings: i2c: dw: Add Baikal-T1 SoC I2C controller
  ...

1 files changed, 103 insertions, 1 deletions

diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c
index 809bcf8387d0..dc0108287ccf 100644
--- a/drivers/i2c/i2c-smbus.c
+++ b/drivers/i2c/i2c-smbus.c
@@ -3,10 +3,11 @@
  * i2c-smbus.c - SMBus extensions to the I2C protocol
  *
  * Copyright (C) 2008 David Brownell
- * Copyright (C) 2010 Jean Delvare <jdelvare@suse.de>
+ * Copyright (C) 2010-2019 Jean Delvare <jdelvare@suse.de>
  */
 
 #include <linux/device.h>
+#include <linux/dmi.h>
 #include <linux/i2c.h>
 #include <linux/i2c-smbus.h>
 #include <linux/interrupt.h>
@@ -196,6 +197,107 @@ EXPORT_SYMBOL_GPL(i2c_handle_smbus_alert);
 
 module_i2c_driver(smbalert_driver);
 
+/*
+ * SPD is not part of SMBus but we include it here for convenience as the
+ * target systems are the same.
+ * Restrictions to automatic SPD instantiation:
+ *  - Only works if all filled slots have the same memory type
+ *  - Only works for DDR2, DDR3 and DDR4 for now
+ *  - Only works on systems with 1 to 4 memory slots
+ */
+#if IS_ENABLED(CONFIG_DMI)
+void i2c_register_spd(struct i2c_adapter *adap)
+{
+	int n, slot_count = 0, dimm_count = 0;
+	u16 handle;
+	u8 common_mem_type = 0x0, mem_type;
+	u64 mem_size;
+	const char *name;
+
+	while ((handle = dmi_memdev_handle(slot_count)) != 0xffff) {
+		slot_count++;
+
+		/* Skip empty slots */
+		mem_size = dmi_memdev_size(handle);
+		if (!mem_size)
+			continue;
+
+		/* Skip undefined memory type */
+		mem_type = dmi_memdev_type(handle);
+		if (mem_type <= 0x02)		/* Invalid, Other, Unknown */
+			continue;
+
+		if (!common_mem_type) {
+			/* First filled slot */
+			common_mem_type = mem_type;
+		} else {
+			/* Check that all filled slots have the same type */
+			if (mem_type != common_mem_type) {
+				dev_warn(&adap->dev,
+					 "Different memory types mixed, not instantiating SPD\n");
+				return;
+			}
+		}
+		dimm_count++;
+	}
+
+	/* No useful DMI data, bail out */
+	if (!dimm_count)
+		return;
+
+	dev_info(&adap->dev, "%d/%d memory slots populated (from DMI)\n",
+		 dimm_count, slot_count);
+
+	if (slot_count > 4) {
+		dev_warn(&adap->dev,
+			 "Systems with more than 4 memory slots not supported yet, not instantiating SPD\n");
+		return;
+	}
+
+	switch (common_mem_type) {
+	case 0x13:	/* DDR2 */
+	case 0x18:	/* DDR3 */
+	case 0x1C:	/* LPDDR2 */
+	case 0x1D:	/* LPDDR3 */
+		name = "spd";
+		break;
+	case 0x1A:	/* DDR4 */
+	case 0x1E:	/* LPDDR4 */
+		name = "ee1004";
+		break;
+	default:
+		dev_info(&adap->dev,
+			 "Memory type 0x%02x not supported yet, not instantiating SPD\n",
+			 common_mem_type);
+		return;
+	}
+
+	/*
+	 * We don't know in which slots the memory modules are. We could
+	 * try to guess from the slot names, but that would be rather complex
+	 * and unreliable, so better probe all possible addresses until we
+	 * have found all memory modules.
+	 */
+	for (n = 0; n < slot_count && dimm_count; n++) {
+		struct i2c_board_info info;
+		unsigned short addr_list[2];
+
+		memset(&info, 0, sizeof(struct i2c_board_info));
+		strlcpy(info.type, name, I2C_NAME_SIZE);
+		addr_list[0] = 0x50 + n;
+		addr_list[1] = I2C_CLIENT_END;
+
+		if (!IS_ERR(i2c_new_scanned_device(adap, &info, addr_list, NULL))) {
+			dev_info(&adap->dev,
+				 "Successfully instantiated SPD at 0x%hx\n",
+				 addr_list[0]);
+			dimm_count--;
+		}
+	}
+}
+EXPORT_SYMBOL_GPL(i2c_register_spd);
+#endif
+
 MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
 MODULE_DESCRIPTION("SMBus protocol extensions support");
 MODULE_LICENSE("GPL");