[PATCH v2 0/5] hw/i2c/bitbang_i2c: Housekeeping

[PATCH v2 0/5] hw/i2c/bitbang_i2c: Housekeeping

[Philippe Mathieu-Daudé]

Series fully reviewed.

Since v1:
- Fixed overwritten RECEIVING_BIT7 entry (Richard)
- Picked R-b tags

- Remove unused dummy MemoryRegion
- Convert DPRINTF() to using trace events

(series used as base for follow-up, better if merged via ARM tree)

Philippe Mathieu-Daudé (5):
  hw/i2c/bitbang_i2c: Define TYPE_GPIO_I2C in public header
  hw/i2c/bitbang_i2c: Remove unused dummy MemoryRegion
  hw/i2c/bitbang_i2c: Change state calling bitbang_i2c_set_state()
    helper
  hw/i2c/bitbang_i2c: Trace state changes
  hw/i2c/bitbang_i2c: Convert DPRINTF() to trace events

 hw/arm/musicpal.c            |  3 +-
 hw/i2c/bitbang_i2c.c         | 80 ++++++++++++++++++++++--------------
 hw/i2c/trace-events          |  7 ++++
 include/hw/i2c/bitbang_i2c.h |  2 +
 4 files changed, 61 insertions(+), 31 deletions(-)

-- 
2.38.1

[PATCH v2 1/5] hw/i2c/bitbang_i2c: Define TYPE_GPIO_I2C in public header

[Philippe Mathieu-Daudé]

Define TYPE_GPIO_I2C in the public "hw/i2c/bitbang_i2c.h"
header and use it in hw/arm/musicpal.c.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 hw/arm/musicpal.c            | 3 ++-
 hw/i2c/bitbang_i2c.c         | 1 -
 include/hw/i2c/bitbang_i2c.h | 2 ++
 3 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/hw/arm/musicpal.c b/hw/arm/musicpal.c
index b65c020115..813232682f 100644
--- a/hw/arm/musicpal.c
+++ b/hw/arm/musicpal.c
@@ -25,6 +25,7 @@
 #include "hw/block/flash.h"
 #include "ui/console.h"
 #include "hw/i2c/i2c.h"
+#include "hw/i2c/bitbang_i2c.h"
 #include "hw/irq.h"
 #include "hw/or-irq.h"
 #include "hw/audio/wm8750.h"
@@ -1300,7 +1301,7 @@ static void musicpal_init(MachineState *machine)
 
     dev = sysbus_create_simple(TYPE_MUSICPAL_GPIO, MP_GPIO_BASE,
                                qdev_get_gpio_in(pic, MP_GPIO_IRQ));
-    i2c_dev = sysbus_create_simple("gpio_i2c", -1, NULL);
+    i2c_dev = sysbus_create_simple(TYPE_GPIO_I2C, -1, NULL);
     i2c = (I2CBus *)qdev_get_child_bus(i2c_dev, "i2c");
 
     lcd_dev = sysbus_create_simple(TYPE_MUSICPAL_LCD, MP_LCD_BASE, NULL);
diff --git a/hw/i2c/bitbang_i2c.c b/hw/i2c/bitbang_i2c.c
index e9a0612a04..ac84bf0262 100644
--- a/hw/i2c/bitbang_i2c.c
+++ b/hw/i2c/bitbang_i2c.c
@@ -162,7 +162,6 @@ void bitbang_i2c_init(bitbang_i2c_interface *s, I2CBus *bus)
 
 /* GPIO interface.  */
 
-#define TYPE_GPIO_I2C "gpio_i2c"
 OBJECT_DECLARE_SIMPLE_TYPE(GPIOI2CState, GPIO_I2C)
 
 struct GPIOI2CState {
diff --git a/include/hw/i2c/bitbang_i2c.h b/include/hw/i2c/bitbang_i2c.h
index 92334e9016..a079e6d70f 100644
--- a/include/hw/i2c/bitbang_i2c.h
+++ b/include/hw/i2c/bitbang_i2c.h
@@ -3,6 +3,8 @@
 
 #include "hw/i2c/i2c.h"
 
+#define TYPE_GPIO_I2C "gpio_i2c"
+
 typedef struct bitbang_i2c_interface bitbang_i2c_interface;
 
 #define BITBANG_I2C_SDA 0
-- 
2.38.1

[PATCH v2 2/5] hw/i2c/bitbang_i2c: Remove unused dummy MemoryRegion

[Philippe Mathieu-Daudé]

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 hw/i2c/bitbang_i2c.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/hw/i2c/bitbang_i2c.c b/hw/i2c/bitbang_i2c.c
index ac84bf0262..e41cb63daa 100644
--- a/hw/i2c/bitbang_i2c.c
+++ b/hw/i2c/bitbang_i2c.c
@@ -165,9 +165,10 @@ void bitbang_i2c_init(bitbang_i2c_interface *s, I2CBus *bus)
 OBJECT_DECLARE_SIMPLE_TYPE(GPIOI2CState, GPIO_I2C)
 
 struct GPIOI2CState {
+    /*< private >*/
     SysBusDevice parent_obj;
+    /*< public >*/
 
-    MemoryRegion dummy_iomem;
     bitbang_i2c_interface bitbang;
     int last_level;
     qemu_irq out;
@@ -188,12 +189,8 @@ static void gpio_i2c_init(Object *obj)
 {
     DeviceState *dev = DEVICE(obj);
     GPIOI2CState *s = GPIO_I2C(obj);
-    SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
     I2CBus *bus;
 
-    memory_region_init(&s->dummy_iomem, obj, "gpio_i2c", 0);
-    sysbus_init_mmio(sbd, &s->dummy_iomem);
-
     bus = i2c_init_bus(dev, "i2c");
     bitbang_i2c_init(&s->bitbang, bus);
 
-- 
2.38.1

[PATCH v2 3/5] hw/i2c/bitbang_i2c: Change state calling bitbang_i2c_set_state() helper

[Philippe Mathieu-Daudé]

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 hw/i2c/bitbang_i2c.c | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/hw/i2c/bitbang_i2c.c b/hw/i2c/bitbang_i2c.c
index e41cb63daa..bf4b781393 100644
--- a/hw/i2c/bitbang_i2c.c
+++ b/hw/i2c/bitbang_i2c.c
@@ -26,13 +26,19 @@ do { printf("bitbang_i2c: " fmt , ## __VA_ARGS__); } while (0)
 #define DPRINTF(fmt, ...) do {} while(0)
 #endif
 
+static void bitbang_i2c_set_state(bitbang_i2c_interface *i2c,
+                                  bitbang_i2c_state state)
+{
+    i2c->state = state;
+}
+
 static void bitbang_i2c_enter_stop(bitbang_i2c_interface *i2c)
 {
     DPRINTF("STOP\n");
     if (i2c->current_addr >= 0)
         i2c_end_transfer(i2c->bus);
     i2c->current_addr = -1;
-    i2c->state = STOPPED;
+    bitbang_i2c_set_state(i2c, STOPPED);
 }
 
 /* Set device data pin.  */
@@ -69,7 +75,7 @@ int bitbang_i2c_set(bitbang_i2c_interface *i2c, int line, int level)
         if (level == 0) {
             DPRINTF("START\n");
             /* START condition.  */
-            i2c->state = SENDING_BIT7;
+            bitbang_i2c_set_state(i2c, SENDING_BIT7);
             i2c->current_addr = -1;
         } else {
             /* STOP condition.  */
@@ -96,7 +102,7 @@ int bitbang_i2c_set(bitbang_i2c_interface *i2c, int line, int level)
     case SENDING_BIT7 ... SENDING_BIT0:
         i2c->buffer = (i2c->buffer << 1) | data;
         /* will end up in WAITING_FOR_ACK */
-        i2c->state++; 
+        bitbang_i2c_set_state(i2c, i2c->state + 1);
         return bitbang_i2c_ret(i2c, 1);
 
     case WAITING_FOR_ACK:
@@ -117,13 +123,14 @@ int bitbang_i2c_set(bitbang_i2c_interface *i2c, int line, int level)
              * device we were sending to decided to NACK us).
              */
             DPRINTF("Got NACK\n");
+            bitbang_i2c_set_state(i2c, SENT_NACK);
             bitbang_i2c_enter_stop(i2c);
             return bitbang_i2c_ret(i2c, 1);
         }
         if (i2c->current_addr & 1) {
-            i2c->state = RECEIVING_BIT7;
+            bitbang_i2c_set_state(i2c, RECEIVING_BIT7);
         } else {
-            i2c->state = SENDING_BIT7;
+            bitbang_i2c_set_state(i2c, SENDING_BIT7);
         }
         return bitbang_i2c_ret(i2c, 0);
     }
@@ -134,18 +141,18 @@ int bitbang_i2c_set(bitbang_i2c_interface *i2c, int line, int level)
     case RECEIVING_BIT6 ... RECEIVING_BIT0:
         data = i2c->buffer >> 7;
         /* will end up in SENDING_ACK */
-        i2c->state++;
+        bitbang_i2c_set_state(i2c, i2c->state + 1);
         i2c->buffer <<= 1;
         return bitbang_i2c_ret(i2c, data);
 
     case SENDING_ACK:
-        i2c->state = RECEIVING_BIT7;
         if (data != 0) {
             DPRINTF("NACKED\n");
-            i2c->state = SENT_NACK;
+            bitbang_i2c_set_state(i2c, SENT_NACK);
             i2c_nack(i2c->bus);
         } else {
             DPRINTF("ACKED\n");
+            bitbang_i2c_set_state(i2c, RECEIVING_BIT7);
         }
         return bitbang_i2c_ret(i2c, 1);
     }
-- 
2.38.1

[PATCH v2 4/5] hw/i2c/bitbang_i2c: Trace state changes

[Philippe Mathieu-Daudé]

Trace bitbang state machine changes with trace events.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 hw/i2c/bitbang_i2c.c | 33 ++++++++++++++++++++++++++++-----
 hw/i2c/trace-events  |  3 +++
 2 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/hw/i2c/bitbang_i2c.c b/hw/i2c/bitbang_i2c.c
index bf4b781393..8a67ff6fae 100644
--- a/hw/i2c/bitbang_i2c.c
+++ b/hw/i2c/bitbang_i2c.c
@@ -16,6 +16,7 @@
 #include "hw/sysbus.h"
 #include "qemu/module.h"
 #include "qom/object.h"
+#include "trace.h"
 
 //#define DEBUG_BITBANG_I2C
 
@@ -26,15 +27,41 @@ do { printf("bitbang_i2c: " fmt , ## __VA_ARGS__); } while (0)
 #define DPRINTF(fmt, ...) do {} while(0)
 #endif
 
+/* bitbang_i2c_state enum to name */
+static const char *sname[] = {
+#define NAME(e) [e] = stringify(e)
+    NAME(STOPPED),
+    [SENDING_BIT7] = "SENDING_BIT7 (START)",
+    NAME(SENDING_BIT6),
+    NAME(SENDING_BIT5),
+    NAME(SENDING_BIT4),
+    NAME(SENDING_BIT3),
+    NAME(SENDING_BIT2),
+    NAME(SENDING_BIT1),
+    NAME(SENDING_BIT0),
+    NAME(WAITING_FOR_ACK),
+    [RECEIVING_BIT7] = "RECEIVING_BIT7 (ACK)",
+    NAME(RECEIVING_BIT6),
+    NAME(RECEIVING_BIT5),
+    NAME(RECEIVING_BIT4),
+    NAME(RECEIVING_BIT3),
+    NAME(RECEIVING_BIT2),
+    NAME(RECEIVING_BIT1),
+    NAME(RECEIVING_BIT0),
+    NAME(SENDING_ACK),
+    NAME(SENT_NACK)
+#undef NAME
+};
+
 static void bitbang_i2c_set_state(bitbang_i2c_interface *i2c,
                                   bitbang_i2c_state state)
 {
+    trace_bitbang_i2c_state(sname[i2c->state], sname[state]);
     i2c->state = state;
 }
 
 static void bitbang_i2c_enter_stop(bitbang_i2c_interface *i2c)
 {
-    DPRINTF("STOP\n");
     if (i2c->current_addr >= 0)
         i2c_end_transfer(i2c->bus);
     i2c->current_addr = -1;
@@ -73,7 +100,6 @@ int bitbang_i2c_set(bitbang_i2c_interface *i2c, int line, int level)
             return bitbang_i2c_nop(i2c);
         }
         if (level == 0) {
-            DPRINTF("START\n");
             /* START condition.  */
             bitbang_i2c_set_state(i2c, SENDING_BIT7);
             i2c->current_addr = -1;
@@ -122,7 +148,6 @@ int bitbang_i2c_set(bitbang_i2c_interface *i2c, int line, int level)
             /* NACK (either addressing a nonexistent device, or the
              * device we were sending to decided to NACK us).
              */
-            DPRINTF("Got NACK\n");
             bitbang_i2c_set_state(i2c, SENT_NACK);
             bitbang_i2c_enter_stop(i2c);
             return bitbang_i2c_ret(i2c, 1);
@@ -147,11 +172,9 @@ int bitbang_i2c_set(bitbang_i2c_interface *i2c, int line, int level)
 
     case SENDING_ACK:
         if (data != 0) {
-            DPRINTF("NACKED\n");
             bitbang_i2c_set_state(i2c, SENT_NACK);
             i2c_nack(i2c->bus);
         } else {
-            DPRINTF("ACKED\n");
             bitbang_i2c_set_state(i2c, RECEIVING_BIT7);
         }
         return bitbang_i2c_ret(i2c, 1);
diff --git a/hw/i2c/trace-events b/hw/i2c/trace-events
index af181d43ee..2a479c1c12 100644
--- a/hw/i2c/trace-events
+++ b/hw/i2c/trace-events
@@ -1,5 +1,8 @@
 # See docs/devel/tracing.rst for syntax documentation.
 
+# bitbang_i2c.c
+bitbang_i2c_state(const char *old_state, const char *new_state) "state %s -> %s"
+
 # core.c
 
 i2c_event(const char *event, uint8_t address) "%s(addr:0x%02x)"
-- 
2.38.1

Re: [PATCH v2 4/5] hw/i2c/bitbang_i2c: Trace state changes

[Richard Henderson]

On 1/10/23 00:29, Philippe Mathieu-Daudé wrote:
> +static const char *sname[] = {

Oh,

   const char * const sname[]

should have caught that the first time.


r~

[PATCH v2 5/5] hw/i2c/bitbang_i2c: Convert DPRINTF() to trace events

[Philippe Mathieu-Daudé]

Convert the remaining DPRINTF debug macro uses to tracepoints.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 hw/i2c/bitbang_i2c.c | 18 ++++++------------
 hw/i2c/trace-events  |  4 ++++
 2 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/hw/i2c/bitbang_i2c.c b/hw/i2c/bitbang_i2c.c
index 8a67ff6fae..d6589f0d4a 100644
--- a/hw/i2c/bitbang_i2c.c
+++ b/hw/i2c/bitbang_i2c.c
@@ -18,14 +18,6 @@
 #include "qom/object.h"
 #include "trace.h"
 
-//#define DEBUG_BITBANG_I2C
-
-#ifdef DEBUG_BITBANG_I2C
-#define DPRINTF(fmt, ...) \
-do { printf("bitbang_i2c: " fmt , ## __VA_ARGS__); } while (0)
-#else
-#define DPRINTF(fmt, ...) do {} while(0)
-#endif
 
 /* bitbang_i2c_state enum to name */
 static const char *sname[] = {
@@ -71,8 +63,10 @@ static void bitbang_i2c_enter_stop(bitbang_i2c_interface *i2c)
 /* Set device data pin.  */
 static int bitbang_i2c_ret(bitbang_i2c_interface *i2c, int level)
 {
+    trace_bitbang_i2c_data(i2c->last_clock, i2c->last_data,
+                           i2c->device_out, level);
     i2c->device_out = level;
-    //DPRINTF("%d %d %d\n", i2c->last_clock, i2c->last_data, i2c->device_out);
+
     return level & i2c->last_data;
 }
 
@@ -137,11 +131,11 @@ int bitbang_i2c_set(bitbang_i2c_interface *i2c, int line, int level)
 
         if (i2c->current_addr < 0) {
             i2c->current_addr = i2c->buffer;
-            DPRINTF("Address 0x%02x\n", i2c->current_addr);
+            trace_bitbang_i2c_addr(i2c->current_addr);
             ret = i2c_start_transfer(i2c->bus, i2c->current_addr >> 1,
                                      i2c->current_addr & 1);
         } else {
-            DPRINTF("Sent 0x%02x\n", i2c->buffer);
+            trace_bitbang_i2c_send(i2c->buffer);
             ret = i2c_send(i2c->bus, i2c->buffer);
         }
         if (ret) {
@@ -161,7 +155,7 @@ int bitbang_i2c_set(bitbang_i2c_interface *i2c, int line, int level)
     }
     case RECEIVING_BIT7:
         i2c->buffer = i2c_recv(i2c->bus);
-        DPRINTF("RX byte 0x%02x\n", i2c->buffer);
+        trace_bitbang_i2c_recv(i2c->buffer);
         /* Fall through... */
     case RECEIVING_BIT6 ... RECEIVING_BIT0:
         data = i2c->buffer >> 7;
diff --git a/hw/i2c/trace-events b/hw/i2c/trace-events
index 2a479c1c12..b0ab237b0f 100644
--- a/hw/i2c/trace-events
+++ b/hw/i2c/trace-events
@@ -2,6 +2,10 @@
 
 # bitbang_i2c.c
 bitbang_i2c_state(const char *old_state, const char *new_state) "state %s -> %s"
+bitbang_i2c_addr(uint8_t addr) "Address 0x%02x"
+bitbang_i2c_send(uint8_t byte) "TX byte 0x%02x"
+bitbang_i2c_recv(uint8_t byte) "RX byte 0x%02x"
+bitbang_i2c_data(unsigned dat, unsigned clk, unsigned old_out, unsigned new_out) "dat %u clk %u out %u -> %u"
 
 # core.c
 
-- 
2.38.1