synclink_gt: add clock options

Add support for x8 asynchronous sample rate and ability to specify base
clock frequency.

Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 39 insertions, 20 deletions

diff --git a/drivers/char/synclink_gt.c b/drivers/char/synclink_gt.c
index 6ec6e13d47d7..5e256494686a 100644
--- a/drivers/char/synclink_gt.c
+++ b/drivers/char/synclink_gt.c
@@ -298,6 +298,7 @@ struct slgt_info {
 
         unsigned int rbuf_fill_level;
         unsigned int if_mode;
+        unsigned int base_clock;
 
         /* device status */
 
@@ -1156,22 +1157,26 @@ static long set_params32(struct slgt_info *info, struct MGSL_PARAMS32 __user *ne
                 return -EFAULT;
 
         spin_lock(&info->lock);
-        info->params.mode            = tmp_params.mode;
-        info->params.loopback        = tmp_params.loopback;
-        info->params.flags           = tmp_params.flags;
-        info->params.encoding        = tmp_params.encoding;
-        info->params.clock_speed     = tmp_params.clock_speed;
-        info->params.addr_filter     = tmp_params.addr_filter;
-        info->params.crc_type        = tmp_params.crc_type;
-        info->params.preamble_length = tmp_params.preamble_length;
-        info->params.preamble        = tmp_params.preamble;
-        info->params.data_rate       = tmp_params.data_rate;
-        info->params.data_bits       = tmp_params.data_bits;
-        info->params.stop_bits       = tmp_params.stop_bits;
-        info->params.parity          = tmp_params.parity;
+        if (tmp_params.mode == MGSL_MODE_BASE_CLOCK) {
+                info->base_clock = tmp_params.clock_speed;
+        } else {
+                info->params.mode            = tmp_params.mode;
+                info->params.loopback        = tmp_params.loopback;
+                info->params.flags           = tmp_params.flags;
+                info->params.encoding        = tmp_params.encoding;
+                info->params.clock_speed     = tmp_params.clock_speed;
+                info->params.addr_filter     = tmp_params.addr_filter;
+                info->params.crc_type        = tmp_params.crc_type;
+                info->params.preamble_length = tmp_params.preamble_length;
+                info->params.preamble        = tmp_params.preamble;
+                info->params.data_rate       = tmp_params.data_rate;
+                info->params.data_bits       = tmp_params.data_bits;
+                info->params.stop_bits       = tmp_params.stop_bits;
+                info->params.parity          = tmp_params.parity;
+        }
         spin_unlock(&info->lock);
 
-        change_params(info);
+        program_hw(info);
 
         return 0;
 }
@@ -2559,10 +2564,13 @@ static int set_params(struct slgt_info *info, MGSL_PARAMS __user *new_params)
                 return -EFAULT;
 
         spin_lock_irqsave(&info->lock, flags);
-        memcpy(&info->params, &tmp_params, sizeof(MGSL_PARAMS));
+        if (tmp_params.mode == MGSL_MODE_BASE_CLOCK)
+                info->base_clock = tmp_params.clock_speed;
+        else
+                memcpy(&info->params, &tmp_params, sizeof(MGSL_PARAMS));
         spin_unlock_irqrestore(&info->lock, flags);
 
-        change_params(info);
+        program_hw(info);
 
         return 0;
 }
@@ -3432,6 +3440,7 @@ static struct slgt_info *alloc_dev(int adapter_num, int port_num, struct pci_dev
                 info->magic = MGSL_MAGIC;
                 INIT_WORK(&info->task, bh_handler);
                 info->max_frame_size = 4096;
+                info->base_clock = 14745600;
                 info->rbuf_fill_level = DMABUFSIZE;
                 info->port.close_delay = 5*HZ/10;
                 info->port.closing_wait = 30*HZ;
@@ -3779,7 +3788,7 @@ static void enable_loopback(struct slgt_info *info)
 static void set_rate(struct slgt_info *info, u32 rate)
 {
         unsigned int div;
-        static unsigned int osc = 14745600;
+        unsigned int osc = info->base_clock;
 
         /* div = osc/rate - 1
          *
@@ -4083,18 +4092,27 @@ static void async_mode(struct slgt_info *info)
          * 06  CTS      IRQ enable
          * 05  DCD      IRQ enable
          * 04  RI       IRQ enable
-         * 03  reserved, must be zero
+         * 03  0=16x sampling, 1=8x sampling
          * 02  1=txd->rxd internal loopback enable
          * 01  reserved, must be zero
          * 00  1=master IRQ enable
          */
         val = BIT15 + BIT14 + BIT0;
+        /* JCR[8] : 1 = x8 async mode feature available */
+        if ((rd_reg32(info, JCR) & BIT8) && info->params.data_rate &&
+            ((info->base_clock < (info->params.data_rate * 16)) ||
+             (info->base_clock % (info->params.data_rate * 16)))) {
+                /* use 8x sampling */
+                val |= BIT3;
+                set_rate(info, info->params.data_rate * 8);
+        } else {
+                /* use 16x sampling */
+                set_rate(info, info->params.data_rate * 16);
+        }
         wr_reg16(info, SCR, val);
 
         slgt_irq_on(info, IRQ_RXBREAK | IRQ_RXOVER);
 
-        set_rate(info, info->params.data_rate * 16);
-
         if (info->params.loopback)
                 enable_loopback(info);
 }
diff --git a/include/linux/synclink.h b/include/linux/synclink.h
index 99b8bdb17b2b..0ff2779c44d0 100644
--- a/include/linux/synclink.h
+++ b/include/linux/synclink.h
@@ -125,6 +125,7 @@
 #define MGSL_MODE_MONOSYNC      3
 #define MGSL_MODE_BISYNC        4
 #define MGSL_MODE_RAW           6
+#define MGSL_MODE_BASE_CLOCK    7
 
 #define MGSL_BUS_TYPE_ISA       1
 #define MGSL_BUS_TYPE_EISA      2