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

Pull i2c fixes from Wolfram Sang:
 "This is a bit larger than usual at rc4 time. The reason is due to
  Lee's work of fixing newly reported build warnings.

  The rest is fixes as usual"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (22 commits)
  MAINTAINERS: adjust to removing i2c designware platform data
  i2c: s3c2410: fix possible NULL pointer deref on read message after write
  i2c: mediatek: Disable i2c start_en and clear intr_stat brfore reset
  i2c: i801: Don't generate an interrupt on bus reset
  i2c: mpc: implement erratum A-004447 workaround
  powerpc/fsl: set fsl,i2c-erratum-a004447 flag for P1010 i2c controllers
  powerpc/fsl: set fsl,i2c-erratum-a004447 flag for P2041 i2c controllers
  dt-bindings: i2c: mpc: Add fsl,i2c-erratum-a004447 flag
  i2c: busses: i2c-stm32f4: Remove incorrectly placed ' ' from function name
  i2c: busses: i2c-st: Fix copy/paste function misnaming issues
  i2c: busses: i2c-pnx: Provide descriptions for 'alg_data' data structure
  i2c: busses: i2c-ocores: Place the expected function names into the documentation headers
  i2c: busses: i2c-eg20t: Fix 'bad line' issue and provide description for 'msgs' param
  i2c: busses: i2c-designware-master: Fix misnaming of 'i2c_dw_init_master()'
  i2c: busses: i2c-cadence: Fix incorrectly documented 'enum cdns_i2c_slave_mode'
  i2c: busses: i2c-ali1563: File headers are not good candidates for kernel-doc
  i2c: muxes: i2c-arb-gpio-challenge: Demote non-conformant kernel-doc headers
  i2c: busses: i2c-nomadik: Fix formatting issue pertaining to 'timeout'
  i2c: sh_mobile: Use new clock calculation formulas for RZ/G2E
  i2c: I2C_HISI should depend on ACPI
  ...

1 files changed, 79 insertions, 2 deletions

diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
index 30d9e89a3db2..dcca9c2396db 100644
--- a/drivers/i2c/busses/i2c-mpc.c
+++ b/drivers/i2c/busses/i2c-mpc.c
@@ -19,6 +19,7 @@
 
 #include <linux/clk.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/fsl_devices.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
@@ -45,6 +46,7 @@
 #define CCR_MTX  0x10
 #define CCR_TXAK 0x08
 #define CCR_RSTA 0x04
+#define CCR_RSVD 0x02
 
 #define CSR_MCF  0x80
 #define CSR_MAAS 0x40
@@ -97,7 +99,7 @@ struct mpc_i2c {
 	u32 block;
 	int rc;
 	int expect_rxack;
-
+	bool has_errata_A004447;
 };
 
 struct mpc_i2c_divider {
@@ -136,6 +138,75 @@ static void mpc_i2c_fixup(struct mpc_i2c *i2c)
 	}
 }
 
+static int i2c_mpc_wait_sr(struct mpc_i2c *i2c, int mask)
+{
+	void __iomem *addr = i2c->base + MPC_I2C_SR;
+	u8 val;
+
+	return readb_poll_timeout(addr, val, val & mask, 0, 100);
+}
+
+/*
+ * Workaround for Erratum A004447. From the P2040CE Rev Q
+ *
+ * 1.  Set up the frequency divider and sampling rate.
+ * 2.  I2CCR - a0h
+ * 3.  Poll for I2CSR[MBB] to get set.
+ * 4.  If I2CSR[MAL] is set (an indication that SDA is stuck low), then go to
+ *     step 5. If MAL is not set, then go to step 13.
+ * 5.  I2CCR - 00h
+ * 6.  I2CCR - 22h
+ * 7.  I2CCR - a2h
+ * 8.  Poll for I2CSR[MBB] to get set.
+ * 9.  Issue read to I2CDR.
+ * 10. Poll for I2CSR[MIF] to be set.
+ * 11. I2CCR - 82h
+ * 12. Workaround complete. Skip the next steps.
+ * 13. Issue read to I2CDR.
+ * 14. Poll for I2CSR[MIF] to be set.
+ * 15. I2CCR - 80h
+ */
+static void mpc_i2c_fixup_A004447(struct mpc_i2c *i2c)
+{
+	int ret;
+	u32 val;
+
+	writeccr(i2c, CCR_MEN | CCR_MSTA);
+	ret = i2c_mpc_wait_sr(i2c, CSR_MBB);
+	if (ret) {
+		dev_err(i2c->dev, "timeout waiting for CSR_MBB\n");
+		return;
+	}
+
+	val = readb(i2c->base + MPC_I2C_SR);
+
+	if (val & CSR_MAL) {
+		writeccr(i2c, 0x00);
+		writeccr(i2c, CCR_MSTA | CCR_RSVD);
+		writeccr(i2c, CCR_MEN | CCR_MSTA | CCR_RSVD);
+		ret = i2c_mpc_wait_sr(i2c, CSR_MBB);
+		if (ret) {
+			dev_err(i2c->dev, "timeout waiting for CSR_MBB\n");
+			return;
+		}
+		val = readb(i2c->base + MPC_I2C_DR);
+		ret = i2c_mpc_wait_sr(i2c, CSR_MIF);
+		if (ret) {
+			dev_err(i2c->dev, "timeout waiting for CSR_MIF\n");
+			return;
+		}
+		writeccr(i2c, CCR_MEN | CCR_RSVD);
+	} else {
+		val = readb(i2c->base + MPC_I2C_DR);
+		ret = i2c_mpc_wait_sr(i2c, CSR_MIF);
+		if (ret) {
+			dev_err(i2c->dev, "timeout waiting for CSR_MIF\n");
+			return;
+		}
+		writeccr(i2c, CCR_MEN);
+	}
+}
+
 #if defined(CONFIG_PPC_MPC52xx) || defined(CONFIG_PPC_MPC512x)
 static const struct mpc_i2c_divider mpc_i2c_dividers_52xx[] = {
 	{20, 0x20}, {22, 0x21}, {24, 0x22}, {26, 0x23},
@@ -670,7 +741,10 @@ static int fsl_i2c_bus_recovery(struct i2c_adapter *adap)
 {
 	struct mpc_i2c *i2c = i2c_get_adapdata(adap);
 
-	mpc_i2c_fixup(i2c);
+	if (i2c->has_errata_A004447)
+		mpc_i2c_fixup_A004447(i2c);
+	else
+		mpc_i2c_fixup(i2c);
 
 	return 0;
 }
@@ -767,6 +841,9 @@ static int fsl_i2c_probe(struct platform_device *op)
 	}
 	dev_info(i2c->dev, "timeout %u us\n", mpc_ops.timeout * 1000000 / HZ);
 
+	if (of_property_read_bool(op->dev.of_node, "fsl,i2c-erratum-a004447"))
+		i2c->has_errata_A004447 = true;
+
 	i2c->adap = mpc_ops;
 	scnprintf(i2c->adap.name, sizeof(i2c->adap.name),
 		  "MPC adapter (%s)", of_node_full_name(op->dev.of_node));