memory: brcmstb: dpfe: support new way of passing data from the DCPU

The DCPU can now send message data in two ways:
  - via the data RAM, as before (this is now message type 0)
  - via the message RAM (this is message type 1)

In order to support both methods, we check the message type of the
response (bits 31:28) and then treat the offset (bits 27:0)
accordingly.

Signed-off-by: Markus Mayer <mmayer@broadcom.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

1 files changed, 55 insertions, 10 deletions

diff --git a/drivers/memory/brcmstb_dpfe.c b/drivers/memory/brcmstb_dpfe.c
index 2013a91217a9..e9c1485c32b9 100644
--- a/drivers/memory/brcmstb_dpfe.c
+++ b/drivers/memory/brcmstb_dpfe.c
@@ -45,8 +45,16 @@
 #define REG_TO_DCPU_MBOX        0x10
 #define REG_TO_HOST_MBOX        0x14
 
+/* Macros to process offsets returned by the DCPU */
+#define DRAM_MSG_ADDR_OFFSET    0x0
+#define DRAM_MSG_TYPE_OFFSET    0x1c
+#define DRAM_MSG_ADDR_MASK      ((1UL << DRAM_MSG_TYPE_OFFSET) - 1)
+#define DRAM_MSG_TYPE_MASK      ((1UL << \
+                                 (BITS_PER_LONG - DRAM_MSG_TYPE_OFFSET)) - 1)
+
 /* Message RAM */
-#define DCPU_MSG_RAM(x)         (0x100 + (x) * sizeof(u32))
+#define DCPU_MSG_RAM_START      0x100
+#define DCPU_MSG_RAM(x)         (DCPU_MSG_RAM_START + (x) * sizeof(u32))
 
 /* DRAM Info Offsets & Masks */
 #define DRAM_INFO_INTERVAL      0x0
@@ -255,6 +263,40 @@ static unsigned int get_msg_chksum(const u32 msg[])
         return sum;
 }
 
+static void __iomem *get_msg_ptr(struct private_data *priv, u32 response,
+                                 char *buf, ssize_t *size)
+{
+        unsigned int msg_type;
+        unsigned int offset;
+        void __iomem *ptr = NULL;
+
+        msg_type = (response >> DRAM_MSG_TYPE_OFFSET) & DRAM_MSG_TYPE_MASK;
+        offset = (response >> DRAM_MSG_ADDR_OFFSET) & DRAM_MSG_ADDR_MASK;
+
+        /*
+         * msg_type == 1: the offset is relative to the message RAM
+         * msg_type == 0: the offset is relative to the data RAM (this is the
+         *                previous way of passing data)
+         * msg_type is anything else: there's critical hardware problem
+         */
+        switch (msg_type) {
+        case 1:
+                ptr = priv->regs + DCPU_MSG_RAM_START + offset;
+                break;
+        case 0:
+                ptr = priv->dmem + offset;
+                break;
+        default:
+                dev_emerg(priv->dev, "invalid message reply from DCPU: %#x\n",
+                        response);
+                if (buf && size)
+                        *size = sprintf(buf,
+                                "FATAL: communication error with DCPU\n");
+        }
+
+        return ptr;
+}
+
 static int __send_command(struct private_data *priv, unsigned int cmd,
                           u32 result[])
 {
@@ -528,7 +570,6 @@ static ssize_t show_refresh(struct device *dev,
         u32 response[MSG_FIELD_MAX];
         void __iomem *info;
         struct private_data *priv;
-        unsigned int offset;
         u8 refresh, sr_abort, ppre, thermal_offs, tuf;
         u32 mr4;
         ssize_t ret;
@@ -538,8 +579,10 @@ static ssize_t show_refresh(struct device *dev,
                 return ret;
 
         priv = dev_get_drvdata(dev);
-        offset = response[MSG_ARG0];
-        info = priv->dmem + offset;
+
+        info = get_msg_ptr(priv, response[MSG_ARG0], buf, &ret);
+        if (!info)
+                return ret;
 
         mr4 = readl_relaxed(info + DRAM_INFO_MR4) & DRAM_INFO_MR4_MASK;
 
@@ -561,7 +604,6 @@ static ssize_t store_refresh(struct device *dev, struct device_attribute *attr,
         u32 response[MSG_FIELD_MAX];
         struct private_data *priv;
         void __iomem *info;
-        unsigned int offset;
         unsigned long val;
         int ret;
 
@@ -574,8 +616,10 @@ static ssize_t store_refresh(struct device *dev, struct device_attribute *attr,
         if (ret)
                 return ret;
 
-        offset = response[MSG_ARG0];
-        info = priv->dmem + offset;
+        info = get_msg_ptr(priv, response[MSG_ARG0], NULL, NULL);
+        if (!info)
+                return -EIO;
+
         writel_relaxed(val, info + DRAM_INFO_INTERVAL);
 
         return count;
@@ -587,16 +631,17 @@ static ssize_t show_vendor(struct device *dev, struct device_attribute *devattr,
         u32 response[MSG_FIELD_MAX];
         struct private_data *priv;
         void __iomem *info;
-        unsigned int offset;
         ssize_t ret;
 
         ret = generic_show(DPFE_CMD_GET_VENDOR, response, dev, buf);
         if (ret)
                 return ret;
 
-        offset = response[MSG_ARG0];
         priv = dev_get_drvdata(dev);
-        info = priv->dmem + offset;
+
+        info = get_msg_ptr(priv, response[MSG_ARG0], buf, &ret);
+        if (!info)
+                return ret;
 
         return sprintf(buf, "%#x %#x %#x %#x %#x\n",
                        readl_relaxed(info + DRAM_VENDOR_MR5) & DRAM_VENDOR_MASK,