Add read buffer to bitbang, improving performance.

[openocd.git] / src / jtag / drivers / sysfsgpio.c

diff --git a/src/jtag/drivers/sysfsgpio.c b/src/jtag/drivers/sysfsgpio.c
index b8acfa2fc387ac92a5f6a5ac0cbfafa373595e53..5a4651df194b85f9a3e38ba714422b992678085a 100644 (file)
--- a/src/jtag/drivers/sysfsgpio.c
+++ b/src/jtag/drivers/sysfsgpio.c
@@ -244,7 +244,7 @@ static void sysfsgpio_swdio_write(int swclk, int swdio)
  * The sysfs value will read back either '0' or '1'. The trick here is to call
  * lseek to bypass buffering in the sysfs kernel driver.
  */
-static int sysfsgpio_read(void)
+static bb_value_t sysfsgpio_read(void)
 {
        char buf[1];
 
@@ -257,7 +257,7 @@ static int sysfsgpio_read(void)
                return 0;
        }
 
-       return buf[0] != '0';
+       return buf[0] == '0' ? BB_LOW : BB_HIGH;
 }
 
 /*
@@ -266,11 +266,11 @@ static int sysfsgpio_read(void)
  * Seeing as this is the only function where the outputs are changed,
  * we can cache the old value to avoid needlessly writing it.
  */
-static void sysfsgpio_write(int tck, int tms, int tdi)
+static int sysfsgpio_write(int tck, int tms, int tdi)
 {
        if (swd_mode) {
                sysfsgpio_swdio_write(tck, tdi);
-               return;
+               return ERROR_OK;
        }
 
        const char one[] = "1";
@@ -312,6 +312,8 @@ static void sysfsgpio_write(int tck, int tms, int tdi)
        last_tdi = tdi;
        last_tms = tms;
        last_tck = tck;
+
+       return ERROR_OK;
 }
 
 /*
@@ -319,7 +321,7 @@ static void sysfsgpio_write(int tck, int tms, int tdi)
  *
  * (1) assert or (0) deassert reset lines
  */
-static void sysfsgpio_reset(int trst, int srst)
+static int sysfsgpio_reset(int trst, int srst)
 {
        LOG_DEBUG("sysfsgpio_reset");
        const char one[] = "1";
@@ -339,6 +341,8 @@ static void sysfsgpio_reset(int trst, int srst)
                if (bytes_written != 1)
                        LOG_WARNING("writing trst failed");
        }
+
+       return ERROR_OK;
 }
 
 COMMAND_HANDLER(sysfsgpio_handle_jtag_gpionums)