Add 8/16/32 bits and BE/LE versions of wait_for_bit. This is needed for reading registers that are not aligned to 32 bits, and for Big Endian platforms.
Signed-off-by: Álvaro Fernández Rojas noltari@gmail.com Reviewed-by: Daniel Schwierzeck daniel.schwierzeck@gmail.com Reviewed-by: Jagan Teki jagan@openedev.com --- v8: no changes. v7: Introduce changes suggested by Daniel Schwierzeck: - Use const void* reg for compatibility with 64 bit systems. - Remove prefix and use __func__ instead. v6: Introduce changes suggested by Jagan Teki: - Switch to wait_for_bit instead of infinite loop.
include/wait_bit.h | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+)
diff --git a/include/wait_bit.h b/include/wait_bit.h index 06ad43a122..bde6d2cfc3 100644 --- a/include/wait_bit.h +++ b/include/wait_bit.h @@ -69,5 +69,66 @@ static inline int wait_for_bit(const char *prefix, const u32 *reg, return -ETIMEDOUT; }
+/** + * wait_for_bit_x() waits for bit set/cleared in register + * + * Function polls register waiting for specific bit(s) change + * (either 0->1 or 1->0). It can fail under two conditions: + * - Timeout + * - User interaction (CTRL-C) + * Function succeeds only if all bits of masked register are set/cleared + * (depending on set option). + * + * @param reg Register that will be read (using read_x()) + * @param mask Bit(s) of register that must be active + * @param set Selects wait condition (bit set or clear) + * @param timeout_ms Timeout (in milliseconds) + * @param breakable Enables CTRL-C interruption + * @return 0 on success, -ETIMEDOUT or -EINTR on failure + */ + +#define BUILD_WAIT_FOR_BIT(sfx, type, read) \ + \ +static inline int wait_for_bit_##sfx(const void *reg, \ + const type mask, \ + const bool set, \ + const unsigned int timeout_ms, \ + const bool breakable) \ +{ \ + type val; \ + unsigned long start = get_timer(0); \ + \ + while (1) { \ + val = read(reg); \ + \ + if (!set) \ + val = ~val; \ + \ + if ((val & mask) == mask) \ + return 0; \ + \ + if (get_timer(start) > timeout_ms) \ + break; \ + \ + if (breakable && ctrlc()) { \ + puts("Abort\n"); \ + return -EINTR; \ + } \ + \ + udelay(1); \ + WATCHDOG_RESET(); \ + } \ + \ + debug("%s: Timeout (reg=%p mask=%x wait_set=%i)\n", __func__, \ + reg, mask, set); \ + \ + return -ETIMEDOUT; \ +} + +BUILD_WAIT_FOR_BIT(8, u8, readb) +BUILD_WAIT_FOR_BIT(le16, u16, readw) +BUILD_WAIT_FOR_BIT(be16, u16, readw_be) +BUILD_WAIT_FOR_BIT(le32, u32, readl) +BUILD_WAIT_FOR_BIT(be32, u32, readl_be)
#endif