[PATCH v7 05/17] scsi: ufs: add support to read device and string descriptors

From: Yaniv Gardi
Date: Tue Mar 08 2016 - 07:41:18 EST


This change adds support to read device descriptor and string descriptor
from a UFS device

Reviewed-by: Gilad Broner <gbroner@xxxxxxxxxxxxxx>
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>
Signed-off-by: Raviv Shvili <rshvili@xxxxxxxxxxxxxx>
Signed-off-by: Yaniv Gardi <ygardi@xxxxxxxxxxxxxx>

---
drivers/scsi/ufs/ufs.h | 1 +
drivers/scsi/ufs/ufshcd.c | 88 ++++++++++++++++++++++++++++++++++++++++++++++-
drivers/scsi/ufs/ufshcd.h | 7 ++++
3 files changed, 95 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
index 54a16ce..aacb235 100644
--- a/drivers/scsi/ufs/ufs.h
+++ b/drivers/scsi/ufs/ufs.h
@@ -43,6 +43,7 @@
#define GENERAL_UPIU_REQUEST_SIZE 32
#define QUERY_DESC_MAX_SIZE 255
#define QUERY_DESC_MIN_SIZE 2
+#define QUERY_DESC_HDR_SIZE 2
#define QUERY_OSF_SIZE (GENERAL_UPIU_REQUEST_SIZE - \
(sizeof(struct utp_upiu_header)))

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 80031e6..e2ed415 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -39,7 +39,7 @@

#include <linux/async.h>
#include <linux/devfreq.h>
-
+#include <linux/nls.h>
#include <linux/of.h>
#include "ufshcd.h"
#include "unipro.h"
@@ -232,6 +232,16 @@ static inline void ufshcd_disable_irq(struct ufs_hba *hba)
}
}

+/* replace non-printable or non-ASCII characters with spaces */
+static inline void ufshcd_remove_non_printable(char *val)
+{
+ if (!val)
+ return;
+
+ if (*val < 0x20 || *val > 0x7e)
+ *val = ' ';
+}
+
/*
* ufshcd_wait_for_register - wait for register value to change
* @hba - per-adapter interface
@@ -2021,6 +2031,82 @@ static inline int ufshcd_read_power_desc(struct ufs_hba *hba,
return ufshcd_read_desc(hba, QUERY_DESC_IDN_POWER, 0, buf, size);
}

+int ufshcd_read_device_desc(struct ufs_hba *hba, u8 *buf, u32 size)
+{
+ return ufshcd_read_desc(hba, QUERY_DESC_IDN_DEVICE, 0, buf, size);
+}
+EXPORT_SYMBOL(ufshcd_read_device_desc);
+
+/**
+ * ufshcd_read_string_desc - read string descriptor
+ * @hba: pointer to adapter instance
+ * @desc_index: descriptor index
+ * @buf: pointer to buffer where descriptor would be read
+ * @size: size of buf
+ * @ascii: if true convert from unicode to ascii characters
+ *
+ * Return 0 in case of success, non-zero otherwise
+ */
+int ufshcd_read_string_desc(struct ufs_hba *hba, int desc_index, u8 *buf,
+ u32 size, bool ascii)
+{
+ int err = 0;
+
+ err = ufshcd_read_desc(hba,
+ QUERY_DESC_IDN_STRING, desc_index, buf, size);
+
+ if (err) {
+ dev_err(hba->dev, "%s: reading String Desc failed after %d retries. err = %d\n",
+ __func__, QUERY_REQ_RETRIES, err);
+ goto out;
+ }
+
+ if (ascii) {
+ int desc_len;
+ int ascii_len;
+ int i;
+ char *buff_ascii;
+
+ desc_len = buf[0];
+ /* remove header and divide by 2 to move from UTF16 to UTF8 */
+ ascii_len = (desc_len - QUERY_DESC_HDR_SIZE) / 2 + 1;
+ if (size < ascii_len + QUERY_DESC_HDR_SIZE) {
+ dev_err(hba->dev, "%s: buffer allocated size is too small\n",
+ __func__);
+ err = -ENOMEM;
+ goto out;
+ }
+
+ buff_ascii = kmalloc(ascii_len, GFP_KERNEL);
+ if (!buff_ascii) {
+ err = -ENOMEM;
+ goto out_free_buff;
+ }
+
+ /*
+ * the descriptor contains string in UTF16 format
+ * we need to convert to utf-8 so it can be displayed
+ */
+ utf16s_to_utf8s((wchar_t *)&buf[QUERY_DESC_HDR_SIZE],
+ desc_len - QUERY_DESC_HDR_SIZE,
+ UTF16_BIG_ENDIAN, buff_ascii, ascii_len);
+
+ /* replace non-printable or non-ASCII characters with spaces */
+ for (i = 0; i < ascii_len; i++)
+ ufshcd_remove_non_printable(&buff_ascii[i]);
+
+ memset(buf + QUERY_DESC_HDR_SIZE, 0,
+ size - QUERY_DESC_HDR_SIZE);
+ memcpy(buf + QUERY_DESC_HDR_SIZE, buff_ascii, ascii_len);
+ buf[QUERY_DESC_LENGTH_OFFSET] = ascii_len + QUERY_DESC_HDR_SIZE;
+out_free_buff:
+ kfree(buff_ascii);
+ }
+out:
+ return err;
+}
+EXPORT_SYMBOL(ufshcd_read_string_desc);
+
/**
* ufshcd_read_unit_desc_param - read the specified unit descriptor parameter
* @hba: Pointer to adapter instance
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index a6d3572..54e13cc 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -678,6 +678,13 @@ static inline int ufshcd_dme_peer_get(struct ufs_hba *hba,
return ufshcd_dme_get_attr(hba, attr_sel, mib_val, DME_PEER);
}

+int ufshcd_read_device_desc(struct ufs_hba *hba, u8 *buf, u32 size);
+
+#define ASCII_STD true
+
+int ufshcd_read_string_desc(struct ufs_hba *hba, int desc_index, u8 *buf,
+ u32 size, bool ascii);
+
/* Expose Query-Request API */
int ufshcd_query_flag(struct ufs_hba *hba, enum query_opcode opcode,
enum flag_idn idn, bool *flag_res);
--
1.8.5.2

--
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