scsi: ufs: set the device reference clock setting

From: Subhash Jadavani <[email protected]>

UFS host supplies the reference clock to UFS device and UFS device specification allows host to provide one of the 4 frequencies (19.2 MHz, 26 MHz, 38.4 MHz, 52 MHz) for reference clock. Host should set the device reference clock frequency setting in the device based on what frequency it is supplying to UFS device.

Signed-off-by Subhash Jadavani <[email protected]>

Signed-off-by Can Guo <[email protected]>

Signed-off-by Sayali Lokhande <[email protected]>

---
 drivers/scsi/ufs/ufs.h           | 14 +++++++
 drivers/scsi/ufs/ufshcd-pltfrm.c |  2 +
 drivers/scsi/ufs/ufshcd.c        | 90 ++++++++++++++++++++++++++++++++++++++++
 drivers/scsi/ufs/ufshcd.h        |  2 +
 4 files changed, 108 insertions(+)

drivers/scsi/ufs/ufs.h +14 -0

index 14e5bf7..a2e76b1 100644
@@ -378,6 +378,20 @@ enum query_opcode {
        UPIU_QUERY_OPCODE_TOGGLE_FLAG   = 0x8,
 };
 
+/* bRefClkFreq attribute values */
+enum ufs_ref_clk_freq {
+       REF_CLK_FREQ_19_2_MHZ   = 0,
+       REF_CLK_FREQ_26_MHZ     = 1,
+       REF_CLK_FREQ_38_4_MHZ   = 2,
+       REF_CLK_FREQ_52_MHZ     = 3,
+       REF_CLK_FREQ_INVAL      = -1,
+};
+
+struct ufs_ref_clk {
+       u32 freq_hz;
+       enum ufs_ref_clk_freq val;
+};
+
 /* Query response result code */
 enum {
        QUERY_RESULT_SUCCESS                    = 0x00,

drivers/scsi/ufs/ufshcd-pltfrm.c +2 -0

index e82bde0..0953563 100644
@@ -343,6 +343,8 @@ int ufshcd_pltfrm_init(struct platform_device *pdev,
        pm_runtime_set_active(&pdev->dev);
        pm_runtime_enable(&pdev->dev);
 
+       ufshcd_parse_dev_ref_clk_freq(hba);
+
        ufshcd_init_lanes_per_dir(hba);
 
        err = ufshcd_init(hba, mmio_base, irq);

drivers/scsi/ufs/ufshcd.c +69 -0

index c5b1bf1..e01cdc0 100644
@@ -6296,6 +6296,89 @@ static void ufshcd_def_desc_sizes(struct ufs_hba *hba)
        hba->desc_size.hlth_desc = QUERY_DESC_HEALTH_DEF_SIZE;
 }
 
+static struct ufs_ref_clk ufs_ref_clk_freqs[] = {
+       {19200000, REF_CLK_FREQ_19_2_MHZ},
+       {26000000, REF_CLK_FREQ_26_MHZ},
+       {38400000, REF_CLK_FREQ_38_4_MHZ},
+       {52000000, REF_CLK_FREQ_52_MHZ},
+       {0, REF_CLK_FREQ_INVAL},
+};
+
+static inline enum ufs_ref_clk_freq
+ufs_get_bref_clk_from_hz(u32 freq)
+{
+       int i = 0;
+
+       while (ufs_ref_clk_freqs[i].freq_hz != freq) {
+               if (!ufs_ref_clk_freqs[i].freq_hz)
+                       return REF_CLK_FREQ_INVAL;
+               i++;
+       }
+
+       return ufs_ref_clk_freqs[i].val;
+}
+
+void ufshcd_parse_dev_ref_clk_freq(struct ufs_hba *hba)
+{
+       struct device *dev = hba->dev;
+       struct device_node *np = dev->of_node;
+       struct clk *refclk = NULL;
+       u32 freq = 0;
+
+       if (!np)
+               return;
+
+       refclk = of_clk_get_by_name(np, "ref_clk");
+       if (!refclk)
+               return;
+
+       freq = clk_get_rate(refclk);
+
+       hba->dev_ref_clk_freq =
+               ufs_get_bref_clk_from_hz(freq);
+
+       if (hba->dev_ref_clk_freq == REF_CLK_FREQ_INVAL)
+               dev_err(hba->dev,
+               "%s: invalid ref_clk setting = %d\n",
+               __func__, freq);
+}
+
+static int ufshcd_set_dev_ref_clk(struct ufs_hba *hba)
+{
+       int err, ref_clk = -1;
+       u32 freq = hba->dev_ref_clk_freq;
+
+       err = ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_READ_ATTR,
+                       QUERY_ATTR_IDN_REF_CLK_FREQ, 0, 0, &ref_clk);
+
+       if (err) {
+               dev_err(hba->dev, "%s: failed reading bRefClkFreq. err = %d\n",
+                        __func__, err);
+               goto out;
+       }
+
+       if (ref_clk == hba->dev_ref_clk_freq)
+               goto out; /* nothing to update */
+
+       err = ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
+                       QUERY_ATTR_IDN_REF_CLK_FREQ, 0, 0, &freq);
+
+       if (err) {
+               dev_err(hba->dev, "%s: bRefClkFreq setting to %u Hz failed\n",

This patch adds configfs support to provision UFS device at runtime. This feature can be primarily useful in factory or assembly line as some devices may be required to be configured multiple times during initial system development phase. Configuration Descriptors can be written multiple times until bConfigDescrLock attribute is zero.

Configuration descriptor buffer consists of Device and Unit descriptor configurable parameters which are parsed from vendor specific provisioning file and then passed via configfs node at runtime to provision ufs device.
CONFIG_CONFIGFS_FS and CONFIG_UFS_PROVISION needs to be enabled for using this feature.

Usage:
1) To read current configuration descriptor with index X (where index X can be 0/1/2/3) :
cat /config/<device_name>/ufs_config_desc_X

2) To write configuration descriptor with index X :
echo <config_desc_buf> > /config/<device_name>/ufs_config_desc_X

Signed-off-by Sayali Lokhande <[email protected]>

---

drivers/scsi/ufs/ufs-configfs.c new file +0 -0

new file mode 100644
index 0000000..84ccb1a
@@ -0,0 +1,237 @@

drivers/scsi/ufs/ufs-configfs.c new file +34 -0

+static ssize_t ufs_config_desc_0_show(struct config_item *item, char *buf)
+{
+       return ufs_config_desc_show(item, buf, 0);
+}
+
+static ssize_t ufs_config_desc_0_store(struct config_item *item,
+                                      const char *buf, size_t count)
+{
+       return ufshcd_desc_configfs_store(item, buf, count, 0);
+}
+
+static ssize_t ufs_config_desc_1_show(struct config_item *item, char *buf)
+{
+       return ufs_config_desc_show(item, buf, 1);
+}
+
+static ssize_t ufs_config_desc_1_store(struct config_item *item,
+                                      const char *buf, size_t count)
+{
+       return ufshcd_desc_configfs_store(item, buf, count, 1);
+}
+
+static ssize_t ufs_config_desc_2_show(struct config_item *item, char *buf)
+{
+       return ufs_config_desc_show(item, buf, 2);
+}
+
+static ssize_t ufs_config_desc_2_store(struct config_item *item,
+                                      const char *buf, size_t count)
+{
+       return ufshcd_desc_configfs_store(item, buf, count, 2);
+}
+
+static ssize_t ufs_config_desc_3_show(struct config_item *item, char *buf)

drivers/scsi/ufs/ufs-configfs.c new file +43 -0

+static struct configfs_attribute ufshcd_attr_provision_0 = {
+       .ca_name        = "ufs_config_desc_0",
+       .ca_mode        = 0644,
+       .ca_owner       = THIS_MODULE,
+       .show           = ufs_config_desc_0_show,
+       .store          = ufs_config_desc_0_store,
+};
+
+static struct configfs_attribute ufshcd_attr_provision_1 = {
+       .ca_name        = "ufs_config_desc_1",
+       .ca_mode        = 0644,
+       .ca_owner       = THIS_MODULE,
+       .show           = ufs_config_desc_1_show,
+       .store          = ufs_config_desc_1_store,
+};
+
+static struct configfs_attribute ufshcd_attr_provision_2 = {
+       .ca_name        = "ufs_config_desc_2",
+       .ca_mode        = 0644,
+       .ca_owner       = THIS_MODULE,
+       .show           = ufs_config_desc_2_show,
+       .store          = ufs_config_desc_2_store,
+};
+
+static struct configfs_attribute ufshcd_attr_provision_3 = {
+       .ca_name        = "ufs_config_desc_3",
+       .ca_mode        = 0644,
+       .ca_owner       = THIS_MODULE,
+       .show           = ufs_config_desc_3_show,
+       .store          = ufs_config_desc_3_store,
+};
+
+static struct configfs_attribute *ufshcd_attrs[] = {
+       &ufshcd_attr_provision_0,
+       &ufshcd_attr_provision_1,
+       &ufshcd_attr_provision_2,
+       &ufshcd_attr_provision_3,
+       NULL,
+};
+
+static struct config_item_type ufscfg_type = {
+       .ct_attrs       = ufshcd_attrs,
+       .ct_owner       = THIS_MODULE,

drivers/scsi/ufs/ufs-configfs.c new file +16 -0

+       cg_item->ci_type = &ufscfg_type;
+
+       subsys = &hba->subsys;
+       config_group_init(&subsys->su_group);
+       mutex_init(&subsys->su_mutex);
+       ret = configfs_register_subsystem(subsys);
+       if (ret)
+               pr_err("Error %d while registering subsystem %s\n",
+                      ret,
+                      subsys->su_group.cg_item.ci_namebuf);
+}
+
+void ufshcd_configfs_exit(struct ufs_hba *hba)
+{
+       configfs_unregister_subsystem(&hba->subsys);
+}

Quoted 24 lines · Sayali Lokhande

This patch adds configfs support to provision UFS device at runtime. This feature can be primarily useful in factory or assembly line as some devices may be required to be configured multiple times during initial system development phase. Configuration Descriptors can be written multiple times until bConfigDescrLock attribute is zero.

Configuration descriptor buffer consists of Device and Unit descriptor configurable parameters which are parsed from vendor specific provisioning file and then passed via configfs node at runtime to provision ufs device.
CONFIG_CONFIGFS_FS and CONFIG_UFS_PROVISION needs to be enabled for using this feature.

Usage:
1) To read current configuration descriptor with index X

    (where index X can be 0/1/2/3) :
    cat /config/<device_name>/ufs_config_desc_X

2) To write configuration descriptor with index X :
echo <config_desc_buf> > /config/<device_name>/ufs_config_desc_X

Signed-off-by Sayali Lokhande <[email protected]>

---

...

Quoted 6 lines

drivers/scsi/ufs/ufs-configfs.c new file +0 -0

new file mode 100644
index 0000000..84ccb1a
@@ -0,0 +1,237 @@

...

Quoted 34 lines

drivers/scsi/ufs/ufs-configfs.c new file +34 -0

+static ssize_t ufs_config_desc_0_show(struct config_item *item, char *buf)
+{
+       return ufs_config_desc_show(item, buf, 0);
+}
+
+static ssize_t ufs_config_desc_0_store(struct config_item *item,
+                                      const char *buf, size_t count)
+{
+       return ufshcd_desc_configfs_store(item, buf, count, 0);
+}
+
+static ssize_t ufs_config_desc_1_show(struct config_item *item, char *buf)
+{
+       return ufs_config_desc_show(item, buf, 1);
+}
+
+static ssize_t ufs_config_desc_1_store(struct config_item *item,
+                                      const char *buf, size_t count)
+{
+       return ufshcd_desc_configfs_store(item, buf, count, 1);
+}
+
+static ssize_t ufs_config_desc_2_show(struct config_item *item, char *buf)
+{
+       return ufs_config_desc_show(item, buf, 2);
+}
+
+static ssize_t ufs_config_desc_2_store(struct config_item *item,
+                                      const char *buf, size_t count)
+{
+       return ufshcd_desc_configfs_store(item, buf, count, 2);
+}
+
+static ssize_t ufs_config_desc_3_show(struct config_item *item, char *buf)

drivers/scsi/ufs/ufs-configfs.c line 168

Quoted 10 lines

drivers/scsi/ufs/ufs-configfs.c new file +10 -0

+{
+       return ufs_config_desc_show(item, buf, 3);
+}
+
+static ssize_t ufs_config_desc_3_store(struct config_item *item,
+                                      const char *buf, size_t count)
+{
+       return ufshcd_desc_configfs_store(item, buf, count, 3);
+}
+

The copypasta above and below is not my favorite, but I suppose it's either this or wrap it all up in a macro that you stamp down 4 times. I'm not sure if that's really any cleaner, so I guess this is fine.

Quoted 48 lines

drivers/scsi/ufs/ufs-configfs.c new file +48 -0

+static struct configfs_attribute ufshcd_attr_provision_0 = {
+       .ca_name        = "ufs_config_desc_0",
+       .ca_mode        = 0644,
+       .ca_owner       = THIS_MODULE,
+       .show           = ufs_config_desc_0_show,
+       .store          = ufs_config_desc_0_store,
+};
+
+static struct configfs_attribute ufshcd_attr_provision_1 = {
+       .ca_name        = "ufs_config_desc_1",
+       .ca_mode        = 0644,
+       .ca_owner       = THIS_MODULE,
+       .show           = ufs_config_desc_1_show,
+       .store          = ufs_config_desc_1_store,
+};
+
+static struct configfs_attribute ufshcd_attr_provision_2 = {
+       .ca_name        = "ufs_config_desc_2",
+       .ca_mode        = 0644,
+       .ca_owner       = THIS_MODULE,
+       .show           = ufs_config_desc_2_show,
+       .store          = ufs_config_desc_2_store,
+};
+
+static struct configfs_attribute ufshcd_attr_provision_3 = {
+       .ca_name        = "ufs_config_desc_3",
+       .ca_mode        = 0644,
+       .ca_owner       = THIS_MODULE,
+       .show           = ufs_config_desc_3_show,
+       .store          = ufs_config_desc_3_store,
+};
+
+static struct configfs_attribute *ufshcd_attrs[] = {
+       &ufshcd_attr_provision_0,
+       &ufshcd_attr_provision_1,
+       &ufshcd_attr_provision_2,
+       &ufshcd_attr_provision_3,
+       NULL,
+};
+
+static struct config_item_type ufscfg_type = {
+       .ct_attrs       = ufshcd_attrs,
+       .ct_owner       = THIS_MODULE,
+};
+
+void ufshcd_configfs_init(struct ufs_hba *hba, const char *name)
+{
+       int ret;

drivers/scsi/ufs/ufs-configfs.c line 221

Quoted 5 lines

drivers/scsi/ufs/ufs-configfs.c new file +5 -0

+       struct config_item *cg_item;
+       struct configfs_subsystem *subsys;
+
+       cg_item = &hba->subsys.su_group.cg_item;
+       sprintf(cg_item->ci_namebuf, "%s", name);

CONFIGFS_ITEM_NAME_LEN is only 20. Is there anything preventing the device name passed in here from being longer than that? You'd have a nasty overrun on your hands if not. Maybe snprintf here?

Quoted 16 lines

drivers/scsi/ufs/ufs-configfs.c new file +16 -0

+       cg_item->ci_type = &ufscfg_type;
+
+       subsys = &hba->subsys;
+       config_group_init(&subsys->su_group);
+       mutex_init(&subsys->su_mutex);
+       ret = configfs_register_subsystem(subsys);
+       if (ret)
+               pr_err("Error %d while registering subsystem %s\n",
+                      ret,
+                      subsys->su_group.cg_item.ci_namebuf);
+}
+
+void ufshcd_configfs_exit(struct ufs_hba *hba)
+{
+       configfs_unregister_subsystem(&hba->subsys);
+}