path: root/meta-openbmc-mods/meta-common/recipes-bsp/u-boot/files/0027-CPLD-u-boot-commands-support-for-PFR.patch

From cdb62eb60de0b99276ff755b896fc51c8ed2606d Mon Sep 17 00:00:00 2001
From: AppaRao Puli <apparao.puli@linux.intel.com>
Date: Tue, 7 May 2019 11:26:35 +0530
Subject: [PATCH] CPLD u-boot commands support for PFR

Implemented the cpld command in u-boot for
communicating with PFR CPLD.

Tested:
Simulated test on different I2C bus and slave
as we don't have hardware available yet.
ast# cpld dump
*** Dumping CPLD Registers ***
0x0000 |  00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
----------------------------------------------------------
0x0000 |  03 00 00 00 01 09 00 f5 01 09 19 cb 46 4c 45 --
0x0001 |  -- 52 4f 4e 49 43 53 cf 53 2d 31 31 30 30 41 44
0x0002 |  55 -- 30 2d 32 30 31 ca 47 38 34 30 32 -- 2d --
0x0003 |  30 37 c2 30 31 cc 45 58 57 44 36 34 39 30 30 38
.............................
ast# cpld read 0x00
CPLD read successful. Reg:0x00 Val:0x03
ast# cpld write 0x00 0x04
CPLD write successful. Reg:0x00 Val:0x04
ast# cpld read 0x00
CPLD read successful. Reg:0x00 Val:0x04
ast#

Signed-off-by: AppaRao Puli <apparao.puli@linux.intel.com>

---
 cmd/Makefile |   1 +
 cmd/cpld.c   | 244 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 245 insertions(+)
 create mode 100644 cmd/cpld.c

diff --git a/cmd/Makefile b/cmd/Makefile
index a1731be..c8ac0af 100644
--- a/cmd/Makefile
+++ b/cmd/Makefile
@@ -66,6 +66,7 @@ obj-$(CONFIG_CMD_FUSE) += fuse.o
 obj-$(CONFIG_CMD_GETTIME) += gettime.o
 obj-$(CONFIG_CMD_GPIO) += gpio.o
 obj-$(CONFIG_CMD_I2C) += i2c.o
+obj-$(CONFIG_CMD_I2C) += cpld.o
 obj-$(CONFIG_CMD_IOTRACE) += iotrace.o
 obj-$(CONFIG_CMD_HASH) += hash.o
 obj-$(CONFIG_CMD_IDE) += ide.o
diff --git a/cmd/cpld.c b/cmd/cpld.c
new file mode 100644
index 0000000..06b2e98
--- /dev/null
+++ b/cmd/cpld.c
@@ -0,0 +1,244 @@
+/*
+ * Copyright (c) 2018-2019 Intel Corporation
+ * Written by AppaRao Puli <apparao.puli@intel.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <command.h>
+#include <cli.h>
+#include <i2c.h>
+#include <errno.h>
+#include <linux/compiler.h>
+
+#define PFR_CPLD_I2C_BUSNO		4
+#define PFR_CPLD_SLAVE_ADDR		0xE0
+
+#define CPLD_READ_TIMEOUT_ATTEMPTS	5
+
+/* Some CPLD registers are self cleared after read.
+ * We should skip them reading to avoid functionality impact.*/
+/* TODO: Need to get this list from CPLD team. */
+static uchar cpld_reg_skip_read[] = {};
+
+static bool skip_cpld_reg_read(u32 reg)
+{
+	int size = ARRAY_SIZE(cpld_reg_skip_read);
+	for (int i = 0; i < size; i++) {
+		if (reg == cpld_reg_skip_read[i])
+			return true;
+	}
+
+	return false;
+}
+
+static int do_cpld_write(cmd_tbl_t *cmdtp, int flag, int argc,
+			 char *const argv[])
+{
+	int ret = 0;
+	int current_bus_no;
+	u32 reg_addr;
+	uchar value;
+	int chip = (PFR_CPLD_SLAVE_ADDR >> 1);
+
+	if (argc != 3)
+		return CMD_RET_USAGE;
+
+	reg_addr = simple_strtoul(argv[1], NULL, 16);
+	if (reg_addr > 0xFF) {
+		printf("Invalid register. Valid range[0x00-0xFF].");
+		return CMD_RET_FAILURE;
+	}
+	value = simple_strtoul(argv[2], NULL, 16);
+
+	/* Get current I2C bus number to restore later. */
+	current_bus_no = i2c_get_bus_num();
+
+	/* Set I2C bus number to PFR CPLD I2C bus. */
+	ret = i2c_set_bus_num(PFR_CPLD_I2C_BUSNO);
+	if (ret) {
+		printf("Failure changing bus number (%d)\n", ret);
+		ret = CMD_RET_FAILURE;
+		goto done;
+	}
+
+	ret = i2c_write(chip, reg_addr, 1, &value, 1);
+	if (ret) {
+		printf("Error writing the chip: %d\n", ret);
+		ret = CMD_RET_FAILURE;
+		goto done;
+	}
+
+	printf("CPLD write successful. Reg:0x%02x Val:0x%02x\n", reg_addr,
+	       value);
+
+done:
+	/* Restore I2C bus number */
+	if (i2c_set_bus_num(current_bus_no))
+		printf("Error in restoring bus number.\n");
+
+	return ret;
+}
+
+static int do_cpld_read(cmd_tbl_t *cmdtp, int flag, int argc,
+			char *const argv[])
+{
+	int ret = 0;
+	int current_bus_no;
+	u32 reg_addr;
+	uchar value[1];
+	int chip = (PFR_CPLD_SLAVE_ADDR >> 1);
+
+	if (argc != 2)
+		return CMD_RET_USAGE;
+
+	reg_addr = simple_strtoul(argv[1], NULL, 16);
+	if (reg_addr > 0xFF) {
+		printf("Invalid register. Valid range[0x00-0xFF].");
+		return CMD_RET_FAILURE;
+	}
+
+	/* Get current I2C bus number to restore later. */
+	current_bus_no = i2c_get_bus_num();
+
+	/* Set I2C bus number to PFR CPLD I2C bus. */
+	ret = i2c_set_bus_num(PFR_CPLD_I2C_BUSNO);
+	if (ret) {
+		printf("Failure changing bus number (%d)\n", ret);
+		ret = CMD_RET_FAILURE;
+		goto done;
+	}
+
+	if (skip_cpld_reg_read(reg_addr)) {
+		printf("CPLD register(0x%02x) reading is not allowed.\n",
+		       reg_addr);
+		ret = 0;
+		goto done;
+	}
+
+	ret = i2c_read(chip, reg_addr, 1, value, 1);
+	if (ret) {
+		printf("Error reading the chip: %d\n", ret);
+		ret = CMD_RET_FAILURE;
+		goto done;
+	}
+
+	printf("CPLD read successful. Reg:0x%02x Val:0x%02x\n", reg_addr,
+	       value[0]);
+
+done:
+	/* Restore I2C bus number */
+	if (i2c_set_bus_num(current_bus_no))
+		printf("Error in restoring bus number.\n");
+
+	return ret;
+}
+
+static int do_cpld_dump(cmd_tbl_t *cmdtp, int flag, int argc,
+			char *const argv[])
+{
+	int ret = 0;
+	int current_bus_no;
+	u32 reg_addr = 0x00;
+	uchar value[1];
+	int chip = (PFR_CPLD_SLAVE_ADDR >> 1);
+
+	if (argc != 1)
+		return CMD_RET_USAGE;
+
+	/* Get current I2C bus number to restore later. */
+	current_bus_no = i2c_get_bus_num();
+
+	/* Set I2C bus number to PFR CPLD I2C bus. */
+	ret = i2c_set_bus_num(PFR_CPLD_I2C_BUSNO);
+	if (ret) {
+		printf("Failure changing bus number (%d)\n", ret);
+		ret = CMD_RET_FAILURE;
+		goto done;
+	}
+
+	printf("*** Dumping CPLD Registers ***\n", reg_addr, value);
+	printf("0x%04x | ", reg_addr);
+	for (int i = 0; i < 0x10; i++)
+		printf(" %02x", i);
+	printf("\n----------------------------------------------------------\n");
+
+	while (reg_addr <= 0xFF) {
+		if ((reg_addr % 16) == 0)
+			printf("0x%04x | ", (reg_addr / 16));
+
+		if (skip_cpld_reg_read(reg_addr)) {
+			printf(" --");
+		} else {
+			int timeout = 0;
+			while (i2c_read(chip, reg_addr, 1, value, 1) != 0) {
+				if (timeout++ >= CPLD_READ_TIMEOUT_ATTEMPTS) {
+					printf("\nERROR: Reading the chip: %d\n",
+					       ret);
+					ret = CMD_RET_FAILURE;
+					goto done;
+				}
+				/* Need delay for I2C devices continous read */
+				mdelay(3 * timeout);
+			}
+			printf(" %02x", value[0]);
+		}
+
+		reg_addr++;
+		if ((reg_addr % 16) == 0)
+			printf("\n");
+	}
+
+done:
+	/* Restore I2C bus number */
+	if (i2c_set_bus_num(current_bus_no))
+		printf("Error in restoring bus number.\n");
+
+	return ret;
+}
+static cmd_tbl_t cmd_cpld_sub[] = {
+	U_BOOT_CMD_MKENT(dump, 1, 1, do_cpld_dump, "", ""),
+	U_BOOT_CMD_MKENT(read, 2, 1, do_cpld_read, "", ""),
+	U_BOOT_CMD_MKENT(write, 3, 1, do_cpld_write, "", "")
+};
+
+/**
+ * do_cpld() - Handle the "cpld" command-line command
+ * @cmdtp:	Command data struct pointer
+ * @flag:	Command flag
+ * @argc:	Command-line argument count
+ * @argv:	Array of command-line arguments
+ *
+ * Returns zero on success, CMD_RET_USAGE in case of misuse and negative
+ * on error.
+ */
+static int do_cpld(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
+{
+	cmd_tbl_t *c = NULL;
+
+	if (argc < 2)
+		return CMD_RET_USAGE;
+
+	/* Strip off leading 'cpld' command argument */
+	argc--;
+	argv++;
+
+	if (argc)
+		c = find_cmd_tbl(argv[0], cmd_cpld_sub,
+				 ARRAY_SIZE(cmd_cpld_sub));
+
+	if (c)
+		return c->cmd(cmdtp, flag, argc, argv);
+	else
+		return CMD_RET_USAGE;
+}
+
+#ifdef CONFIG_SYS_LONGHELP
+static char cpld_help_text[] =
+	"cpld dump - Dump all CPLD registers.\n"
+	"cpld read <reg> - Read CPLD register.\n"
+	"cpld write <reg> <val> - Write CPLD register.\n";
+#endif
+
+U_BOOT_CMD(cpld, 4, 1, do_cpld, "PFR CPLD information", cpld_help_text);
-- 
2.7.4