[PATCH 1/2] drivers: mmc: write protect single boot area

[Ying-Chun Liu]

From: "Ying-Chun Liu (PaulLiu)" <paul.liu at linaro.org>

Add features to write protect single boot area rather than all boot
areas.

Signed-off-by: Ying-Chun Liu (PaulLiu) <paul.liu at linaro.org>
Cc: Peng Fan <peng.fan at nxp.com>
Cc: Jaehoon Chung <jh80.chung at samsung.com>
---
 drivers/mmc/mmc.c | 27 +++++++++++++++++++++++++++
 include/mmc.h     | 16 ++++++++++++++++
 2 files changed, 43 insertions(+)

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index f6ccd837aa..53f931e993 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -860,6 +860,33 @@ int mmc_boot_wp(struct mmc *mmc)
 	return mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_BOOT_WP, 1);
 }
 
+int mmc_boot_wp_single_partition(struct mmc *mmc, int partition)
+{
+	u8 value;
+	int ret;
+
+	value = EXT_CSD_BOOT_WP_B_PWR_WP_EN;
+
+	if (partition == 0) {
+		value |= EXT_CSD_BOOT_WP_B_SEC_WP_SEL;
+		ret = mmc_switch(mmc,
+				 EXT_CSD_CMD_SET_NORMAL,
+				 EXT_CSD_BOOT_WP,
+				 value);
+	} else if (partition == 1) {
+		value |= EXT_CSD_BOOT_WP_B_SEC_WP_SEL;
+		value |= EXT_CSD_BOOT_WP_B_PWR_WP_SEC_SEL;
+		ret = mmc_switch(mmc,
+				 EXT_CSD_CMD_SET_NORMAL,
+				 EXT_CSD_BOOT_WP,
+				 value);
+	} else {
+		ret = mmc_boot_wp(mmc);
+	}
+
+	return ret;
+}
+
 #if !CONFIG_IS_ENABLED(MMC_TINY)
 static int mmc_set_card_speed(struct mmc *mmc, enum bus_mode mode,
 			      bool hsdowngrade)
diff --git a/include/mmc.h b/include/mmc.h
index 6bdcce881d..a1b3c49af4 100644
--- a/include/mmc.h
+++ b/include/mmc.h
@@ -308,6 +308,10 @@ static inline bool mmc_is_tuning_cmd(uint cmdidx)
 
 #define EXT_CSD_HS_CTRL_REL	(1 << 0)	/* host controlled WR_REL_SET */
 
+#define EXT_CSD_BOOT_WP_B_SEC_WP_SEL	(0x80)	/* enable partition selector */
+#define EXT_CSD_BOOT_WP_B_PWR_WP_SEC_SEL (0x02)	/* partition selector to protect */
+#define EXT_CSD_BOOT_WP_B_PWR_WP_EN	(0x01)	/* power-on write-protect */
+
 #define EXT_CSD_WR_DATA_REL_USR		(1 << 0)	/* user data area WR_REL */
 #define EXT_CSD_WR_DATA_REL_GP(x)	(1 << ((x)+1))	/* GP part (x+1) WR_REL */
 
@@ -980,6 +984,18 @@ int mmc_send_ext_csd(struct mmc *mmc, u8 *ext_csd);
  */
 int mmc_boot_wp(struct mmc *mmc);
 
+/**
+ * mmc_boot_wp_single_partition() - set write protection to a boot partition.
+ *
+ * This function sets a single boot partition to protect and leave the
+ * other partition writable.
+ *
+ * @param mmc the mmc device.
+ * @param partition 0 - first boot partition, 1 - second boot partition.
+ * @return 0 for success
+ */
+int mmc_boot_wp_single_partition(struct mmc *mmc, int partition);
+
 static inline enum dma_data_direction mmc_get_dma_dir(struct mmc_data *data)
 {
 	return data->flags & MMC_DATA_WRITE ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
-- 
2.35.1