ENGR00265414-4 mxc: asrc: Reconstruct req_pair()

The old req_pair() constrained that only Pair B could afford 6 channels,
while actually not. So rewrite it to be more flexible.

Acked-by: Wang Shengjiu <b02247@freescale.com>
Signed-off-by: Nicolin Chen <b42378@freescale.com>
(cherry picked from commit adbc9dbba6ee46c05c0878a8e3bab118981d62c7)

diff --git a/drivers/mxc/asrc/mxc_asrc.c b/drivers/mxc/asrc/mxc_asrc.c
index dc8d6fd6981788659e8ff95631591edd30fcdd30..9a4e175e496e20a64737ff4389eba676cc40bcdc 100644 (file)
--- a/drivers/mxc/asrc/mxc_asrc.c
+++ b/drivers/mxc/asrc/mxc_asrc.c
@@ -321,34 +321,42 @@ int asrc_req_pair(int chn_num, enum asrc_pair_index *index)
        int err = 0;
        unsigned long lock_flags;
        struct asrc_pair *pair;
+       int imax = 0, busy = 0, i;
+
        spin_lock_irqsave(&data_lock, lock_flags);
 
-       if (chn_num > 2) {
-               pair = &g_asrc->asrc_pair[ASRC_PAIR_B];
-               if (pair->active || (chn_num > pair->chn_max))
-                       err = -EBUSY;
-               else {
-                       *index = ASRC_PAIR_B;
-                       pair->chn_num = chn_num;
-                       pair->active = 1;
+       for (i = ASRC_PAIR_A; i < ASRC_PAIR_MAX_NUM; i++) {
+               pair = &g_asrc->asrc_pair[i];
+               if (chn_num > pair->chn_max) {
+                       imax++;
+                       continue;
+               } else if (pair->active) {
+                       busy++;
+                       continue;
                }
+               /* Save the current qualified pair */
+               *index = i;
+
+               /* Check if this pair is a perfect one */
+               if (chn_num == pair->chn_max)
+                       break;
+       }
+
+       if (imax >= ASRC_PAIR_MAX_NUM) {
+               pr_err("No pair could afford requested channel number.\n");
+               err = -EINVAL;
+       } else if (busy >= ASRC_PAIR_MAX_NUM) {
+               pr_err("All pairs are busy now.\n");
+               err = -EBUSY;
+       } else if (busy + imax >= ASRC_PAIR_MAX_NUM) {
+               pr_err("All affordable pairs are busy now.\n");
+               err = -EBUSY;
        } else {
-               pair = &g_asrc->asrc_pair[ASRC_PAIR_A];
-               if (pair->active || (pair->chn_max == 0)) {
-                       pair = &g_asrc->asrc_pair[ASRC_PAIR_C];
-                       if (pair->active || (pair->chn_max == 0))
-                               err = -EBUSY;
-                       else {
-                               *index = ASRC_PAIR_C;
-                               pair->chn_num = 2;
-                               pair->active = 1;
-                       }
-               } else {
-                       *index = ASRC_PAIR_A;
-                       pair->chn_num = 2;
-                       pair->active = 1;
-               }
+               pair = &g_asrc->asrc_pair[*index];
+               pair->chn_num = chn_num;
+               pair->active = 1;
        }
+
        spin_unlock_irqrestore(&data_lock, lock_flags);
 
        if (!err) {
@@ -1857,6 +1865,11 @@ static int asrc_write_proc_attr(struct file *file, const char *buffer,
        reg = na | (nb << g_asrc->mxc_asrc_data->channel_bits) |
                (nc << (g_asrc->mxc_asrc_data->channel_bits * 2));
 
+       /* Update chn_max */
+       g_asrc->asrc_pair[ASRC_PAIR_A].chn_max = na;
+       g_asrc->asrc_pair[ASRC_PAIR_B].chn_max = nb;
+       g_asrc->asrc_pair[ASRC_PAIR_C].chn_max = nc;
+
        clk_enable(g_asrc->mxc_asrc_data->asrc_core_clk);
        __raw_writel(reg, g_asrc->vaddr + ASRC_ASRCNCR_REG);
        clk_disable(g_asrc->mxc_asrc_data->asrc_core_clk);

diff --git a/include/linux/mxc_asrc.h b/include/linux/mxc_asrc.h
index 99f39a4744c6af4085c8c30fe0631c896bb6c241..8de07b92b0ac405d210b041e0a0ba1fb7f69d154 100644 (file)
--- a/include/linux/mxc_asrc.h
+++ b/include/linux/mxc_asrc.h
@@ -40,6 +40,8 @@ enum asrc_pair_index {
        ASRC_PAIR_C
 };
 
+#define ASRC_PAIR_MAX_NUM      (ASRC_PAIR_C + 1)
+
 enum asrc_inclk {
        INCLK_NONE = 0x03,
        INCLK_ESAI_RX = 0x00,