[PATCH v1 1/2] hw: allwinner-i2c: Make the trace message more readable

[qianfanguijin]

From: qianfan Zhao <qianfanguijin@163.com>

Next is an example when allwinner_i2c_rw enabled:

allwinner_i2c_rw write   CNTR[0x0c]: 50 { M_STP BUS_EN  }
allwinner_i2c_rw write   CNTR[0x0c]: e4 { A_ACK M_STA BUS_EN INT_EN  }
allwinner_i2c_rw  read   CNTR[0x0c]: cc { A_ACK INT_FLAG BUS_EN INT_EN }
allwinner_i2c_rw  read   STAT[0x10]: 08 { STAT_M_STA_TX }

Signed-off-by: qianfan Zhao <qianfanguijin@163.com>
---
 hw/i2c/allwinner-i2c.c | 90 +++++++++++++++++++++++++++++++++++++++++-
 hw/i2c/trace-events    |  4 +-
 2 files changed, 89 insertions(+), 5 deletions(-)

diff --git a/hw/i2c/allwinner-i2c.c b/hw/i2c/allwinner-i2c.c
index a435965836..36b387520f 100644
--- a/hw/i2c/allwinner-i2c.c
+++ b/hw/i2c/allwinner-i2c.c
@@ -129,6 +129,39 @@ enum {
     STAT_IDLE = 0x1f
 } TWI_STAT_STA;
 
+#define TWI_STAT_STA_DESC(sta)  [sta] = #sta
+static const char *twi_stat_sta_descriptors[] = {
+    TWI_STAT_STA_DESC(STAT_BUS_ERROR),
+    TWI_STAT_STA_DESC(STAT_M_STA_TX),
+    TWI_STAT_STA_DESC(STAT_M_RSTA_TX),
+    TWI_STAT_STA_DESC(STAT_M_ADDR_WR_ACK),
+    TWI_STAT_STA_DESC(STAT_M_ADDR_WR_NACK),
+    TWI_STAT_STA_DESC(STAT_M_DATA_TX_ACK),
+    TWI_STAT_STA_DESC(STAT_M_DATA_TX_NACK),
+    TWI_STAT_STA_DESC(STAT_M_ARB_LOST),
+    TWI_STAT_STA_DESC(STAT_M_ADDR_RD_ACK),
+    TWI_STAT_STA_DESC(STAT_M_ADDR_RD_NACK),
+    TWI_STAT_STA_DESC(STAT_M_DATA_RX_ACK),
+    TWI_STAT_STA_DESC(STAT_M_DATA_RX_NACK),
+    TWI_STAT_STA_DESC(STAT_S_ADDR_WR_ACK),
+    TWI_STAT_STA_DESC(STAT_S_ARB_LOST_AW_ACK),
+    TWI_STAT_STA_DESC(STAT_S_GCA_ACK),
+    TWI_STAT_STA_DESC(STAT_S_ARB_LOST_GCA_ACK),
+    TWI_STAT_STA_DESC(STAT_S_DATA_RX_SA_ACK),
+    TWI_STAT_STA_DESC(STAT_S_DATA_RX_SA_NACK),
+    TWI_STAT_STA_DESC(STAT_S_DATA_RX_GCA_ACK),
+    TWI_STAT_STA_DESC(STAT_S_DATA_RX_GCA_NACK),
+    TWI_STAT_STA_DESC(STAT_S_STP_RSTA),
+    TWI_STAT_STA_DESC(STAT_S_ADDR_RD_ACK),
+    TWI_STAT_STA_DESC(STAT_S_ARB_LOST_AR_ACK),
+    TWI_STAT_STA_DESC(STAT_S_DATA_TX_ACK),
+    TWI_STAT_STA_DESC(STAT_S_DATA_TX_NACK),
+    TWI_STAT_STA_DESC(STAT_S_LB_TX_ACK),
+    TWI_STAT_STA_DESC(STAT_M_2ND_ADDR_WR_ACK),
+    TWI_STAT_STA_DESC(STAT_M_2ND_ADDR_WR_NACK),
+    TWI_STAT_STA_DESC(STAT_IDLE),
+};
+
 static const char *allwinner_i2c_get_regname(unsigned offset)
 {
     switch (offset) {
@@ -155,6 +188,59 @@ static const char *allwinner_i2c_get_regname(unsigned 
offset)
     }
 }
 
+static const char *twi_cntr_reg_bits[] = {
+    [2] = "A_ACK",
+    [3] = "INT_FLAG",
+    [4] = "M_STP",
+    [5] = "M_STA",
+    [6] = "BUS_EN",
+    [7] = "INT_EN",
+};
+
+static void trace_buffer_append_bit_descriptors(char *s, size_t sz,
+                                                unsigned int value,
+                                                unsigned int start,
+                                                unsigned int end,
+                                                const char **desc_arrays)
+{
+    for (; start <= end; start++) {
+        if (value & (1 << start)) {
+            strncat(s, desc_arrays[start], sz - 1);
+            strncat(s, " ", sz - 1);
+        }
+    }
+}
+
+static void allwinner_i2c_trace_rw(int is_write, unsigned int offset,
+                                   unsigned int value)
+{
+    char s[256] = { 0 };
+
+    snprintf(s, sizeof(s), "%s %6s[0x%02x]: %02x ",
+             is_write ? "write": " read",
+             allwinner_i2c_get_regname(offset), offset,
+             value);
+
+    switch (offset) {
+    case TWI_CNTR_REG:
+        strncat(s, "{ ", sizeof(s) - 1);
+        trace_buffer_append_bit_descriptors(s, sizeof(s), value,
+                                            2, 7, twi_cntr_reg_bits);
+        strncat(s, " }", sizeof(s) - 1);
+        break;
+    case TWI_STAT_REG:
+        if (STAT_TO_STA(value) <= STAT_IDLE) {
+            strncat(s, "{ ", sizeof(s) - 1);
+            strncat(s, twi_stat_sta_descriptors[STAT_TO_STA(value)],
+                    sizeof(s) - 1);
+            strncat(s, " }", sizeof(s) - 1);
+        }
+        break;
+    }
+
+    trace_allwinner_i2c_rw(s);
+}
+
 static inline bool allwinner_i2c_is_reset(AWI2CState *s)
 {
     return s->srst & TWI_SRST_MASK;
@@ -271,7 +357,7 @@ static uint64_t allwinner_i2c_read(void *opaque, hwaddr 
offset,
         break;
     }
 
-    trace_allwinner_i2c_read(allwinner_i2c_get_regname(offset), offset, value);
+    allwinner_i2c_trace_rw(0, (unsigned int)offset, (unsigned int)value);
 
     return (uint64_t)value;
 }
@@ -283,7 +369,7 @@ static void allwinner_i2c_write(void *opaque, hwaddr offset,
 
     value &= 0xff;
 
-    trace_allwinner_i2c_write(allwinner_i2c_get_regname(offset), offset, 
value);
+    allwinner_i2c_trace_rw(1, (unsigned int)offset, (unsigned int)value);
 
     switch (offset) {
     case TWI_ADDR_REG:
diff --git a/hw/i2c/trace-events b/hw/i2c/trace-events
index 8e88aa24c1..fa5e8d5021 100644
--- a/hw/i2c/trace-events
+++ b/hw/i2c/trace-events
@@ -16,9 +16,7 @@ i2c_recv(uint8_t address, uint8_t data) "recv(addr:0x%02x) 
data:0x%02x"
 i2c_ack(void) ""
 
 # allwinner_i2c.c
-
-allwinner_i2c_read(const char* reg_name, uint64_t offset, uint64_t value) 
"read %s [0x%" PRIx64 "]: -> 0x%" PRIx64
-allwinner_i2c_write(const char* reg_name, uint64_t offset, uint64_t value) 
"write %s [0x%" PRIx64 "]: <- 0x%" PRIx64
+allwinner_i2c_rw(const char *s) "%s"
 
 # aspeed_i2c.c
 
-- 
2.25.1