fsi: master-ast-cf: Add new FSI master using Aspeed ColdFire

The Aspeed AST2x00 can contain a ColdFire v1 coprocessor which
is currently unused on OpenPower systems.

This adds an alternative to the fsi-master-gpio driver that
uses that coprocessor instead of bit banging from the ARM
core itself. The end result is about 4 times faster.

The firmware for the coprocessor and its source code can be
found at https://github.com/ozbenh/cf-fsi and is system specific.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

drivers/fsi/Kconfig

@@ -27,6 +27,15 @@ config FSI_MASTER_HUB
 	allow chaining of FSI links to an arbitrary depth.  This allows for
 	a high target device fanout.
 
+config FSI_MASTER_AST_CF
+	tristate "FSI master based on Aspeed ColdFire coprocessor"
+	depends on GPIOLIB
+	depends on GPIO_ASPEED
+	---help---
+	This option enables a FSI master using the AST2400 and AST2500 GPIO
+	lines driven by the internal ColdFire coprocessor. This requires
+	the corresponding machine specific ColdFire firmware to be available.
+
 config FSI_SCOM
 	tristate "SCOM FSI client device driver"
 	---help---

drivers/fsi/Makefile

@@ -2,5 +2,6 @@
 obj-$(CONFIG_FSI) += fsi-core.o
 obj-$(CONFIG_FSI_MASTER_HUB) += fsi-master-hub.o
 obj-$(CONFIG_FSI_MASTER_GPIO) += fsi-master-gpio.o
+obj-$(CONFIG_FSI_MASTER_AST_CF) += fsi-master-ast-cf.o
 obj-$(CONFIG_FSI_SCOM) += fsi-scom.o
 obj-$(CONFIG_FSI_SBEFIFO) += fsi-sbefifo.o

drivers/fsi/cf-fsi-fw.h

+// SPDX-License-Identifier: GPL-2.0+
+#ifndef __CF_FSI_FW_H
+#define __CF_FSI_FW_H
+
+/*
+ * uCode file layout
+ *
+ * 0000...03ff : m68k exception vectors
+ * 0400...04ff : Header info & boot config block
+ * 0500....... : Code & stack
+ */
+
+/*
+ * Header info & boot config area
+ *
+ * The Header info is built into the ucode and provide version and
+ * platform information.
+ *
+ * the Boot config needs to be adjusted by the ARM prior to starting
+ * the ucode if the Command/Status area isn't at 0x320000 in CF space
+ * (ie. beginning of SRAM).
+ */
+
+#define HDR_OFFSET	        0x400
+
+/* Info: Signature & version */
+#define HDR_SYS_SIG		0x00	/* 2 bytes system signature */
+#define  SYS_SIG_SHARED		0x5348
+#define  SYS_SIG_SPLIT		0x5350
+#define HDR_FW_VERS		0x02	/* 2 bytes Major.Minor */
+#define HDR_API_VERS		0x04	/* 2 bytes Major.Minor */
+#define  API_VERSION_MAJ	2	/* Current version */
+#define  API_VERSION_MIN	1
+#define HDR_FW_OPTIONS		0x08	/* 4 bytes option flags */
+#define  FW_OPTION_TRACE_EN	0x00000001	/* FW tracing enabled */
+#define	 FW_OPTION_CONT_CLOCK	0x00000002	/* Continuous clocking supported */
+#define HDR_FW_SIZE		0x10	/* 4 bytes size for combo image */
+
+/* Boot Config: Address of Command/Status area */
+#define HDR_CMD_STAT_AREA	0x80	/* 4 bytes CF address */
+#define HDR_FW_CONTROL		0x84	/* 4 bytes control flags */
+#define	 FW_CONTROL_CONT_CLOCK	0x00000002	/* Continuous clocking enabled */
+#define	 FW_CONTROL_DUMMY_RD	0x00000004	/* Extra dummy read (AST2400) */
+#define	 FW_CONTROL_USE_STOP	0x00000008	/* Use STOP instructions */
+#define HDR_CLOCK_GPIO_VADDR	0x90	/* 2 bytes offset from GPIO base */
+#define HDR_CLOCK_GPIO_DADDR	0x92	/* 2 bytes offset from GPIO base */
+#define HDR_DATA_GPIO_VADDR	0x94	/* 2 bytes offset from GPIO base */
+#define HDR_DATA_GPIO_DADDR	0x96	/* 2 bytes offset from GPIO base */
+#define HDR_TRANS_GPIO_VADDR	0x98	/* 2 bytes offset from GPIO base */
+#define HDR_TRANS_GPIO_DADDR	0x9a	/* 2 bytes offset from GPIO base */
+#define HDR_CLOCK_GPIO_BIT	0x9c	/* 1 byte bit number */
+#define HDR_DATA_GPIO_BIT	0x9d	/* 1 byte bit number */
+#define HDR_TRANS_GPIO_BIT	0x9e	/* 1 byte bit number */
+
+/*
+ *  Command/Status area layout: Main part
+ */
+
+/* Command/Status register:
+ *
+ * +---------------------------+
+ * | STAT | RLEN | CLEN | CMD  |
+ * |   8  |   8  |   8  |   8  |
+ * +---------------------------+
+ *    |       |      |      |
+ *    status  |      |      |
+ * Response len      |      |
+ * (in bits)         |      |
+ *                   |      |
+ *         Command len      |
+ *         (in bits)        |
+ *                          |
+ *               Command code
+ *
+ * Due to the big endian layout, that means that a byte read will
+ * return the status byte
+ */
+#define	CMD_STAT_REG	        0x00
+#define  CMD_REG_CMD_MASK	0x000000ff
+#define  CMD_REG_CMD_SHIFT	0
+#define	  CMD_NONE		0x00
+#define	  CMD_COMMAND		0x01
+#define	  CMD_BREAK		0x02
+#define	  CMD_IDLE_CLOCKS	0x03 /* clen = #clocks */
+#define   CMD_INVALID		0xff
+#define  CMD_REG_CLEN_MASK	0x0000ff00
+#define  CMD_REG_CLEN_SHIFT	8
+#define  CMD_REG_RLEN_MASK	0x00ff0000
+#define  CMD_REG_RLEN_SHIFT	16
+#define  CMD_REG_STAT_MASK	0xff000000
+#define  CMD_REG_STAT_SHIFT	24
+#define	  STAT_WORKING		0x00
+#define	  STAT_COMPLETE		0x01
+#define	  STAT_ERR_INVAL_CMD	0x80
+#define	  STAT_ERR_INVAL_IRQ	0x81
+#define	  STAT_ERR_MTOE		0x82
+
+/* Response tag & CRC */
+#define	STAT_RTAG		0x04
+
+/* Response CRC */
+#define	STAT_RCRC		0x05
+
+/* Echo and Send delay */
+#define	ECHO_DLY_REG		0x08
+#define	SEND_DLY_REG		0x09
+
+/* Command data area
+ *
+ * Last byte of message must be left aligned
+ */
+#define	CMD_DATA		0x10 /* 64 bit of data */
+
+/* Response data area, right aligned, unused top bits are 1 */
+#define	RSP_DATA		0x20 /* 32 bit of data */
+
+/* Misc */
+#define	INT_CNT			0x30 /* 32-bit interrupt count */
+#define	BAD_INT_VEC		0x34 /* 32-bit bad interrupt vector # */
+#define	CF_STARTED		0x38 /* byte, set to -1 when copro started */
+#define	CLK_CNT			0x3c /* 32-bit, clock count (debug only) */
+
+/*
+ *  SRAM layout: GPIO arbitration part
+ */
+#define ARB_REG			0x40
+#define  ARB_ARM_REQ		0x01
+#define  ARB_ARM_ACK		0x02
+
+/* Misc2 */
+#define CF_RESET_D0		0x50
+#define CF_RESET_D1		0x54
+#define BAD_INT_S0		0x58
+#define BAD_INT_S1		0x5c
+#define STOP_CNT		0x60
+
+/* Internal */
+
+/*
+ * SRAM layout: Trace buffer (debug builds only)
+ */
+#define	TRACEBUF		0x100
+#define	  TR_CLKOBIT0		0xc0
+#define	  TR_CLKOBIT1		0xc1
+#define	  TR_CLKOSTART		0x82
+#define	  TR_OLEN		0x83 /* + len */
+#define	  TR_CLKZ		0x84 /* + count */
+#define	  TR_CLKWSTART		0x85
+#define	  TR_CLKTAG		0x86 /* + tag */
+#define	  TR_CLKDATA		0x87 /* + len */
+#define	  TR_CLKCRC		0x88 /* + raw crc */
+#define	  TR_CLKIBIT0		0x90
+#define	  TR_CLKIBIT1		0x91
+#define	  TR_END		0xff
+
+#endif /* __CF_FSI_FW_H */
+

include/trace/events/fsi_master_ast_cf.h

+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM fsi_master_ast_cf
+
+#if !defined(_TRACE_FSI_MASTER_ACF_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_FSI_MASTER_ACF_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(fsi_master_acf_copro_command,
+	TP_PROTO(const struct fsi_master_acf *master, uint32_t op),
+	TP_ARGS(master, op),
+	TP_STRUCT__entry(
+		__field(int,		master_idx)
+		__field(uint32_t,	op)
+	),
+	TP_fast_assign(
+		__entry->master_idx = master->master.idx;
+		__entry->op = op;
+	),
+	TP_printk("fsi-acf%d command %08x",
+		  __entry->master_idx, __entry->op
+	)
+);
+
+TRACE_EVENT(fsi_master_acf_send_request,
+	TP_PROTO(const struct fsi_master_acf *master, const struct fsi_msg *cmd, u8 rbits),
+	TP_ARGS(master, cmd, rbits),
+	TP_STRUCT__entry(
+		__field(int,		master_idx)
+		__field(uint64_t,	msg)
+		__field(u8,		bits)
+		__field(u8,		rbits)
+	),
+	TP_fast_assign(
+		__entry->master_idx = master->master.idx;
+		__entry->msg = cmd->msg;
+		__entry->bits = cmd->bits;
+		__entry->rbits = rbits;
+	),
+	TP_printk("fsi-acf%d cmd: %016llx/%d/%d",
+		__entry->master_idx, (unsigned long long)__entry->msg,
+		__entry->bits, __entry->rbits
+	)
+);
+
+TRACE_EVENT(fsi_master_acf_copro_response,
+	TP_PROTO(const struct fsi_master_acf *master, u8 rtag, u8 rcrc, __be32 rdata, bool crc_ok),
+	TP_ARGS(master, rtag, rcrc, rdata, crc_ok),
+	TP_STRUCT__entry(
+		__field(int,	master_idx)
+		__field(u8,	rtag)
+		__field(u8,	rcrc)
+		__field(u32,    rdata)
+		__field(bool,   crc_ok)
+	),
+	TP_fast_assign(
+		__entry->master_idx = master->master.idx;
+		__entry->rtag = rtag;
+		__entry->rcrc = rcrc;
+		__entry->rdata = be32_to_cpu(rdata);
+		__entry->crc_ok = crc_ok;
+	),
+	TP_printk("fsi-acf%d rsp: tag=%04x crc=%04x data=%08x %c\n",
+		__entry->master_idx, __entry->rtag, __entry->rcrc,
+		__entry->rdata, __entry->crc_ok ? ' ' : '!'
+	)
+);
+
+TRACE_EVENT(fsi_master_acf_crc_rsp_error,
+	TP_PROTO(const struct fsi_master_acf *master, int retries),
+	TP_ARGS(master, retries),
+	TP_STRUCT__entry(
+		__field(int,	master_idx)
+		__field(int,	retries)
+	),
+	TP_fast_assign(
+		__entry->master_idx = master->master.idx;
+		__entry->retries = retries;
+	),
+	TP_printk("fsi-acf%d CRC error in response retry %d",
+		__entry->master_idx, __entry->retries
+	)
+);
+
+TRACE_EVENT(fsi_master_acf_poll_response_busy,
+	TP_PROTO(const struct fsi_master_acf *master, int busy_count),
+	TP_ARGS(master, busy_count),
+	TP_STRUCT__entry(
+		__field(int,	master_idx)
+		__field(int,	busy_count)
+	),
+	TP_fast_assign(
+		__entry->master_idx = master->master.idx;
+		__entry->busy_count = busy_count;
+	),
+	TP_printk("fsi-acf%d: device reported busy %d times",
+		__entry->master_idx, __entry->busy_count
+	)
+);
+
+TRACE_EVENT(fsi_master_acf_cmd_abs_addr,
+	TP_PROTO(const struct fsi_master_acf *master, u32 addr),
+	TP_ARGS(master, addr),
+	TP_STRUCT__entry(
+		__field(int,	master_idx)
+		__field(u32,	addr)
+	),
+	TP_fast_assign(
+		__entry->master_idx = master->master.idx;
+		__entry->addr = addr;
+	),
+	TP_printk("fsi-acf%d: Sending ABS_ADR %06x",
+		__entry->master_idx, __entry->addr
+	)
+);
+
+TRACE_EVENT(fsi_master_acf_cmd_rel_addr,
+	TP_PROTO(const struct fsi_master_acf *master, u32 rel_addr),
+	TP_ARGS(master, rel_addr),
+	TP_STRUCT__entry(
+		__field(int,	master_idx)
+		__field(u32,	rel_addr)
+	),
+	TP_fast_assign(
+		__entry->master_idx = master->master.idx;
+		__entry->rel_addr = rel_addr;
+	),
+	TP_printk("fsi-acf%d: Sending REL_ADR %03x",
+		__entry->master_idx, __entry->rel_addr
+	)
+);
+
+TRACE_EVENT(fsi_master_acf_cmd_same_addr,
+	TP_PROTO(const struct fsi_master_acf *master),
+	TP_ARGS(master),
+	TP_STRUCT__entry(
+		__field(int,	master_idx)
+	),
+	TP_fast_assign(
+		__entry->master_idx = master->master.idx;
+	),
+	TP_printk("fsi-acf%d: Sending SAME_ADR",
+		__entry->master_idx
+	)
+);
+
+#endif /* _TRACE_FSI_MASTER_ACF_H */
+
+#include <trace/define_trace.h>