platform/chrome: cros_ec: Remove cros_ec dependency in lpc_mec

In order to allow this code to be re-used, remove the dependency
on the rest of the cros_ec code from the cros_ec_lpc_mec functions.

Instead of using a hardcoded register base address of 0x800 have
this be passed in to cros_ec_lpc_mec_init().  The existing cros_ec
use case now passes in the 0x800 base address this way.

There are some error checks that happen in cros_ec_lpc_mec_in_range()
that probably shouldn't be there, as they are checking kernel-space
callers and not user-space input. However, we'll just do the refactor in
this patch, and in a future patch might remove this error checking and
fix all the instances of code that calls this.

There's a similar problem in cros_ec_lpc_read_bytes(), where we return a
checksum, but on error just return 0. This should probably be changed so
that it returns int, but we don't want to have to mess with all the
calling code for this fix. Maybe we'll come back through later and fix
this.

Signed-off-by: Duncan Laurie <dlaurie@google.com>
Signed-off-by: Nick Crews <ncrews@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

1 files changed, 24 insertions, 19 deletions

diff --git a/drivers/platform/chrome/cros_ec_lpc_mec.h b/drivers/platform/chrome/cros_ec_lpc_mec.h
index 68b381f2eb50..aa1018f6b0f2 100644
--- a/drivers/platform/chrome/cros_ec_lpc_mec.h
+++ b/drivers/platform/chrome/cros_ec_lpc_mec.h
@@ -8,8 +8,6 @@
 #ifndef __CROS_EC_LPC_MEC_H
 #define __CROS_EC_LPC_MEC_H
 
-#include <linux/mfd/cros_ec_commands.h>
-
 enum cros_ec_lpc_mec_emi_access_mode {
 	/* 8-bit access */
 	ACCESS_TYPE_BYTE = 0x0,
@@ -29,27 +27,23 @@ enum cros_ec_lpc_mec_io_type {
 	MEC_IO_WRITE,
 };
 
-/* Access IO ranges 0x800 thru 0x9ff using EMI interface instead of LPC */
-#define MEC_EMI_RANGE_START EC_HOST_CMD_REGION0
-#define MEC_EMI_RANGE_END   (EC_LPC_ADDR_MEMMAP + EC_MEMMAP_SIZE)
-
 /* EMI registers are relative to base */
-#define MEC_EMI_BASE 0x800
-#define MEC_EMI_HOST_TO_EC (MEC_EMI_BASE + 0)
-#define MEC_EMI_EC_TO_HOST (MEC_EMI_BASE + 1)
-#define MEC_EMI_EC_ADDRESS_B0 (MEC_EMI_BASE + 2)
-#define MEC_EMI_EC_ADDRESS_B1 (MEC_EMI_BASE + 3)
-#define MEC_EMI_EC_DATA_B0 (MEC_EMI_BASE + 4)
-#define MEC_EMI_EC_DATA_B1 (MEC_EMI_BASE + 5)
-#define MEC_EMI_EC_DATA_B2 (MEC_EMI_BASE + 6)
-#define MEC_EMI_EC_DATA_B3 (MEC_EMI_BASE + 7)
+#define MEC_EMI_HOST_TO_EC(MEC_EMI_BASE)	((MEC_EMI_BASE) + 0)
+#define MEC_EMI_EC_TO_HOST(MEC_EMI_BASE)	((MEC_EMI_BASE) + 1)
+#define MEC_EMI_EC_ADDRESS_B0(MEC_EMI_BASE)	((MEC_EMI_BASE) + 2)
+#define MEC_EMI_EC_ADDRESS_B1(MEC_EMI_BASE)	((MEC_EMI_BASE) + 3)
+#define MEC_EMI_EC_DATA_B0(MEC_EMI_BASE)	((MEC_EMI_BASE) + 4)
+#define MEC_EMI_EC_DATA_B1(MEC_EMI_BASE)	((MEC_EMI_BASE) + 5)
+#define MEC_EMI_EC_DATA_B2(MEC_EMI_BASE)	((MEC_EMI_BASE) + 6)
+#define MEC_EMI_EC_DATA_B3(MEC_EMI_BASE)	((MEC_EMI_BASE) + 7)
 
-/*
- * cros_ec_lpc_mec_init
+/**
+ * cros_ec_lpc_mec_init() - Initialize MEC I/O.
  *
- * Initialize MEC I/O.
+ * @base: MEC EMI Base address
+ * @end: MEC EMI End address
  */
-void cros_ec_lpc_mec_init(void);
+void cros_ec_lpc_mec_init(unsigned int base, unsigned int end);
 
 /*
  * cros_ec_lpc_mec_destroy
@@ -59,6 +53,17 @@ void cros_ec_lpc_mec_init(void);
 void cros_ec_lpc_mec_destroy(void);
 
 /**
+ * cros_ec_lpc_mec_in_range() - Determine if addresses are in MEC EMI range.
+ *
+ * @offset: Address offset
+ * @length: Number of bytes to check
+ *
+ * Return: 1 if in range, 0 if not, and -EINVAL on failure
+ *         such as the mec range not being initialized
+ */
+int cros_ec_lpc_mec_in_range(unsigned int offset, unsigned int length);
+
+/**
  * cros_ec_lpc_io_bytes_mec - Read / write bytes to MEC EMI port
  *
  * @io_type: MEC_IO_READ or MEC_IO_WRITE, depending on request