[U-Boot] [PATCH 1/4] x86: cpu: introduce scu_ipc_raw_command()

[Georgii Staroselskii]

This interface will be used to configure properly some pins on
Merrifield that are shared with SCU.

scu_ipc_raw_command() writes SPTR and DPTR registers before sending
a command to SCU.

This code has been ported from Linux work done by Andy Shevchenko.

Signed-off-by: Georgii Staroselskii <georgii.staroselskii at emlid.com>
---
 arch/x86/include/asm/scu.h |  4 ++++
 arch/x86/lib/scu.c         | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/arch/x86/include/asm/scu.h b/arch/x86/include/asm/scu.h
index 7ce5824..f5ec5a1 100644
--- a/arch/x86/include/asm/scu.h
+++ b/arch/x86/include/asm/scu.h
@@ -6,6 +6,8 @@
 #define _X86_ASM_SCU_IPC_H_
 
 /* IPC defines the following message types */
+#define IPCMSG_INDIRECT_READ	0x02
+#define IPCMSG_INDIRECT_WRITE	0x05
 #define IPCMSG_WARM_RESET	0xf0
 #define IPCMSG_COLD_RESET	0xf1
 #define IPCMSG_SOFT_RESET	0xf2
@@ -23,5 +25,7 @@ struct ipc_ifwi_version {
 /* Issue commands to the SCU with or without data */
 int scu_ipc_simple_command(u32 cmd, u32 sub);
 int scu_ipc_command(u32 cmd, u32 sub, u32 *in, int inlen, u32 *out, int outlen);
+int scu_ipc_raw_command(u32 cmd, u32 sub, u32 *in, int inlen, u32 *out,
+			int outlen, u32 dptr, u32 sptr);
 
 #endif	/* _X86_ASM_SCU_IPC_H_ */
diff --git a/arch/x86/lib/scu.c b/arch/x86/lib/scu.c
index caa04c6..847bb77 100644
--- a/arch/x86/lib/scu.c
+++ b/arch/x86/lib/scu.c
@@ -101,6 +101,41 @@ static int scu_ipc_cmd(struct ipc_regs *regs, u32 cmd, u32 sub,
 	return err;
 }
 
+int scu_ipc_raw_command(u32 cmd, u32 sub, u32 *in, int inlen, u32 *out,
+			int outlen, u32 dptr, u32 sptr)
+{
+	int inbuflen = DIV_ROUND_UP(inlen, 4);
+	struct udevice *dev;
+	struct scu *scu;
+	int ret;
+
+	ret = syscon_get_by_driver_data(X86_SYSCON_SCU, &dev);
+	if (ret)
+		return ret;
+
+	scu = dev_get_priv(dev);
+
+	/* Up to 16 bytes */
+	if (inbuflen > 4)
+		return -EINVAL;
+
+	writel(dptr, &scu->regs->dptr);
+	writel(sptr, &scu->regs->sptr);
+
+	/*
+	 * SRAM controller doesn't support 8-bit writes, it only
+	 * supports 32-bit writes, so we have to copy input data into
+	 * the temporary buffer, and SCU FW will use the inlen to
+	 * determine the actual input data length in the temporary
+	 * buffer.
+	 */
+
+	u32 inbuf[4] = {0};
+
+	memcpy(inbuf, in, inlen);
+
+	return scu_ipc_cmd(scu->regs, cmd, sub, inbuf, inlen, out, outlen);
+}
 /**
  * scu_ipc_simple_command() - send a simple command
  * @cmd: command
-- 
2.7.4