mec1322: Add flash physical interface functions

Add physical flash interface for read / write / protection of external
SPI on mec1322.

BUG=chrome-os-partner:36167
TEST=Manual on glower:
flashread 0xf000 0x200 --> dumps 0xff
flashwrite 0xf000 0x200
flashread 0xf000 0x200 --> dumps write pattern
flasherase 0xf000 0x1000
flashread 0xf000 0x200 --> dumps 0xff
spi_flash_prot 0 0x10000
flashinfo --> shows first 64KB protected
spi_flashwrite 0xf000 0x200 --> access denied
spi_flashwrite 0x1f000 0x200 --> OK
flashread 0x1f000 0x200 --> dumps write pattern
BRANCH=None

Change-Id: I2cb20a49934999fc0dd9b3425eb99708711637c5
Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/257132
Reviewed-by: Randall Spangler <rspangler@chromium.org>

4 files changed, 271 insertions, 18 deletions

diff --git a/chip/mec1322/build.mk b/chip/mec1322/build.mk
index abd69b227d..9c9ecd16b5 100644
--- a/chip/mec1322/build.mk
+++ b/chip/mec1322/build.mk
@@ -15,6 +15,7 @@ CFLAGS_CPU+=-march=armv7e-m -mcpu=cortex-m4
 chip-y=clock.o gpio.o hwtimer.o system.o uart.o jtag.o
 chip-$(CONFIG_ADC)+=adc.o
 chip-$(CONFIG_FANS)+=fan.o
+chip-$(CONFIG_FLASH)+=flash.o
 chip-$(CONFIG_I2C)+=i2c.o
 chip-$(CONFIG_LPC)+=lpc.o
 chip-$(CONFIG_PWM)+=pwm.o
diff --git a/chip/mec1322/config_chip.h b/chip/mec1322/config_chip.h
index 9a0d770f50..797a895c3e 100644
--- a/chip/mec1322/config_chip.h
+++ b/chip/mec1322/config_chip.h
@@ -47,25 +47,36 @@
 /* Default task stack size */
 #define TASK_STACK_SIZE             512
 
-#define CONFIG_FLASH_BASE           0x00100000
+/****************************************************************************/
+/* Define our flash layout. */
+/* Protect bank size 4K bytes */
+#define CONFIG_FLASH_BANK_SIZE          0x00001000
+/* Sector erase size 4K bytes */
+#define CONFIG_FLASH_ERASE_SIZE         0x00001000
+/* Minimum write size */
+#define CONFIG_FLASH_WRITE_SIZE         0x00000004
 
-#define CONFIG_FLASH_PHYSICAL_SIZE  0x00018000
+/* One page size for write */
+#define CONFIG_FLASH_WRITE_IDEAL_SIZE   256
 
-/* Size of one firmware image in RAM */
+/* 96KB flash used for program memory */
+#define CONFIG_FLASH_PHYSICAL_SIZE      0x00018000
+/* Program memory base address */
+#define CONFIG_FLASH_BASE               0x00100000
 
-/****************************************************************************/
-/* Define our flash layout. */
+#define CONFIG_CDRAM_BASE               0x00100000
+#define CONFIG_CDRAM_SIZE               0x00020000
 
 /* Size of one firmware image in flash */
 #ifndef CONFIG_FW_IMAGE_SIZE
-#define CONFIG_FW_IMAGE_SIZE		(CONFIG_FLASH_PHYSICAL_SIZE / 2)
+#define CONFIG_FW_IMAGE_SIZE            (CONFIG_FLASH_PHYSICAL_SIZE / 2)
 #endif
 
 /* RO firmware must start at beginning of flash */
-#define CONFIG_FW_RO_OFF		0
+#define CONFIG_FW_RO_OFF                0
 
-#define CONFIG_FW_RO_SIZE		CONFIG_FW_IMAGE_SIZE
-#define CONFIG_FLASH_SIZE		CONFIG_FLASH_PHYSICAL_SIZE
+#define CONFIG_FW_RO_SIZE               CONFIG_FW_IMAGE_SIZE
+#define CONFIG_FLASH_SIZE               CONFIG_FLASH_PHYSICAL_SIZE
 
 /*
  * TODO(crosbug.com/p/37510): Implement a loader to load either RO or RW at
@@ -73,14 +84,18 @@
  * memory, only flash + load RW for now.
  */
 #undef  CONFIG_FW_INCLUDE_RO
-#define CONFIG_FW_RW_OFF		CONFIG_FW_RO_OFF
-#define CONFIG_FW_RW_SIZE		CONFIG_FLASH_PHYSICAL_SIZE
+#define CONFIG_FW_RW_OFF                CONFIG_FW_RO_OFF
+#define CONFIG_FW_RW_SIZE               CONFIG_FLASH_PHYSICAL_SIZE
 
 /* TODO(crosbug.com/p/23796): why 2 sets of configs with the same numbers? */
-#define CONFIG_FW_WP_RO_OFF		CONFIG_FW_RO_OFF
-#define CONFIG_FW_WP_RO_SIZE		CONFIG_FW_RO_SIZE
+#define CONFIG_FW_WP_RO_OFF             CONFIG_FW_RO_OFF
+#define CONFIG_FW_WP_RO_SIZE            CONFIG_FW_RO_SIZE
 
-#define CONFIG_FLASH_BANK_SIZE          4
+/* Non-memmapped, external SPI */
+/* #define CONFIG_CODERAM_ARCH */
+#undef  CONFIG_FLASH_MAPPED
+#undef  CONFIG_FLASH_PSTATE
+#define CONFIG_SPI_FLASH
 
 /****************************************************************************/
 /* Customize the build */
@@ -91,12 +106,10 @@
 #define CONFIG_SWITCH
 #define CONFIG_MPU
 #endif
+#define CONFIG_DMA
+#define CONFIG_FPU
 #define CONFIG_I2C
 #define CONFIG_LPC
-#define CONFIG_FPU
 #define CONFIG_SPI
-#define CONFIG_DMA
-
-#undef CONFIG_FLASH
 
 #endif  /* __CROS_EC_CONFIG_CHIP_H */
diff --git a/chip/mec1322/flash.c b/chip/mec1322/flash.c
new file mode 100644
index 0000000000..fb6f56fc48
--- /dev/null
+++ b/chip/mec1322/flash.c
@@ -0,0 +1,227 @@
+/* Copyright 2015 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "common.h"
+#include "console.h"
+#include "flash.h"
+#include "host_command.h"
+#include "shared_mem.h"
+#include "spi.h"
+#include "spi_flash.h"
+#include "system.h"
+#include "util.h"
+#include "watchdog.h"
+
+#define PAGE_SIZE 256
+
+/**
+ * Read from physical flash.
+ *
+ * @param offset        Flash offset to write.
+ * @param size          Number of bytes to write.
+ * @param data          Destination buffer for data.  Must be 32-bit aligned.
+ */
+int flash_physical_read(int offset, int size, char *data)
+{
+	int ret;
+
+	/* Fail if offset, size, and data aren't at least word-aligned */
+	if ((offset | size | (uint32_t)(uintptr_t)data) & 3)
+		return EC_ERROR_INVAL;
+
+	spi_enable(1);
+	ret = spi_flash_read((uint8_t *)data, offset, size);
+	spi_enable(0);
+	return ret;
+}
+
+/**
+ * Write to physical flash.
+ *
+ * Offset and size must be a multiple of CONFIG_FLASH_WRITE_SIZE.
+ *
+ * @param offset        Flash offset to write.
+ * @param size          Number of bytes to write.
+ * @param data          Data to write to flash.  Must be 32-bit aligned.
+ */
+int flash_physical_write(int offset, int size, const char *data)
+{
+	int ret, i, write_size;
+
+	/* Fail if offset, size, and data aren't at least word-aligned */
+	if ((offset | size | (uint32_t)(uintptr_t)data) & 3)
+		return EC_ERROR_INVAL;
+
+	spi_enable(1);
+	for (i = 0; i < size; i += write_size) {
+		write_size = MIN(size, SPI_FLASH_MAX_WRITE_SIZE);
+		ret = spi_flash_write(offset + i,
+				      write_size,
+				      (uint8_t *)data + i);
+		if (ret != EC_SUCCESS)
+			break;
+		/* BUG: Multi-page writes fail if no delay */
+		msleep(1);
+	}
+	spi_enable(0);
+	return ret;
+}
+
+/**
+ * Erase physical flash.
+ *
+ * Offset and size must be a multiple of CONFIG_FLASH_ERASE_SIZE.
+ *
+ * @param offset        Flash offset to erase.
+ * @param size          Number of bytes to erase.
+ */
+int flash_physical_erase(int offset, int size)
+{
+	int ret;
+
+	spi_enable(1);
+	ret = spi_flash_erase(offset, size);
+	spi_enable(0);
+	return ret;
+}
+
+/**
+ * Read physical write protect setting for a flash bank.
+ *
+ * @param bank    Bank index to check.
+ * @return        non-zero if bank is protected until reboot.
+ */
+int flash_physical_get_protect(int bank)
+{
+	uint32_t addr = bank * CONFIG_FLASH_BANK_SIZE;
+	int ret;
+
+	spi_enable(1);
+	ret = spi_flash_check_protect(addr, CONFIG_FLASH_BANK_SIZE);
+	spi_enable(0);
+	return ret;
+}
+
+/**
+ * Protect flash now.
+ *
+ * @param all      Protect all (=1) or just read-only and pstate (=0).
+ * @return         non-zero if error.
+ */
+int flash_physical_protect_now(int all)
+{
+	int offset, size, ret;
+
+	if (all) {
+		offset = 0;
+		size = CONFIG_FLASH_PHYSICAL_SIZE;
+	} else {
+		offset = CONFIG_FW_RO_OFF;
+		size = CONFIG_FW_RO_SIZE;
+	}
+
+	spi_enable(1);
+	ret = spi_flash_set_protect(offset, size);
+	spi_enable(0);
+	return ret;
+}
+
+/**
+ * Return flash protect state flags from the physical layer.
+ *
+ * This should only be called by flash_get_protect().
+ *
+ * Uses the EC_FLASH_PROTECT_* flags from ec_commands.h
+ */
+uint32_t flash_physical_get_protect_flags(void)
+{
+	uint32_t flags = 0;
+
+	spi_enable(1);
+	if (spi_flash_check_protect(CONFIG_FW_RO_OFF, CONFIG_FW_RO_SIZE)) {
+		flags |= EC_FLASH_PROTECT_RO_AT_BOOT | EC_FLASH_PROTECT_RO_NOW;
+		if (spi_flash_check_protect(CONFIG_FW_RW_OFF,
+					    CONFIG_FW_RW_SIZE))
+			flags |= EC_FLASH_PROTECT_ALL_NOW;
+	}
+	spi_enable(0);
+	return flags;
+}
+
+/**
+ * Return the valid flash protect flags.
+ *
+ * @return   A combination of EC_FLASH_PROTECT_* flags from ec_commands.h
+ */
+uint32_t flash_physical_get_valid_flags(void)
+{
+	return EC_FLASH_PROTECT_RO_AT_BOOT |
+	       EC_FLASH_PROTECT_RO_NOW |
+	       EC_FLASH_PROTECT_ALL_NOW;
+}
+
+/**
+ * Return the writable flash protect flags.
+ *
+ * @param    cur_flags The current flash protect flags.
+ * @return   A combination of EC_FLASH_PROTECT_* flags from ec_commands.h
+ */
+uint32_t flash_physical_get_writable_flags(uint32_t cur_flags)
+{
+	uint32_t ret = 0;
+	enum spi_flash_wp wp_status = spi_flash_check_wp();
+
+	if (wp_status == SPI_WP_NONE || (wp_status == SPI_WP_HARDWARE &&
+	   !(cur_flags & EC_FLASH_PROTECT_GPIO_ASSERTED)))
+		ret = EC_FLASH_PROTECT_RO_AT_BOOT | EC_FLASH_PROTECT_RO_NOW |
+		      EC_FLASH_PROTECT_ALL_NOW;
+
+	return ret;
+}
+
+/**
+ * Enable write protect for the specified range.
+ *
+ * Once write protect is enabled, it will STAY enabled until the system is
+ * hard-rebooted with the hardware write protect pin deasserted.  If the write
+ * protect pin is deasserted, the protect setting is ignored, and the entire
+ * flash will be writable.
+ *
+ * @param range         The range to protect.
+ * @return              EC_SUCCESS, or nonzero if error.
+ */
+int flash_physical_protect_at_boot(enum flash_wp_range range)
+{
+	int offset, size, ret;
+
+	switch (range) {
+	case FLASH_WP_NONE:
+		offset = size = 0;
+		break;
+	case FLASH_WP_RO:
+		offset = CONFIG_FW_RO_OFF;
+		size = CONFIG_FW_RO_SIZE;
+		break;
+	case FLASH_WP_ALL:
+		offset = 0;
+		size = CONFIG_FLASH_PHYSICAL_SIZE;
+		break;
+	}
+
+	spi_enable(1);
+	ret = spi_flash_set_protect(offset, size);
+	spi_enable(0);
+	return ret;
+}
+
+/**
+ * Initialize the module.
+ *
+ * Applies at-boot protection settings if necessary.
+ */
+int flash_pre_init(void)
+{
+	return EC_SUCCESS;
+}
diff --git a/chip/mec1322/system.c b/chip/mec1322/system.c
index e682852935..b94e93ff07 100644
--- a/chip/mec1322/system.c
+++ b/chip/mec1322/system.c
@@ -369,3 +369,15 @@ void htimer_interrupt(void)
 	/* Time to wake up */
 }
 DECLARE_IRQ(MEC1322_IRQ_HTIMER, htimer_interrupt, 1);
+
+/* TODO(crosbug.com/p/37510): Implement bootloader */
+enum system_image_copy_t system_get_shrspi_image_copy(void)
+{
+	return SYSTEM_IMAGE_RW;
+}
+
+/* TODO(crosbug.com/p/37510): Implement bootloader */
+uint32_t system_get_lfw_address(uint32_t flash_addr)
+{
+	return CONFIG_FW_RO_OFF;
+}