Staging: olpc_dcon: replace some magic numbers

This patch replace some magic numbers. I believe it makes
the driver more readable.

The magic number 0x26 is the XO system embedded controller
(EC) command 'DCON power enable/disable'.

Number 0x41, and 0x42 are special memory controller settings
register.  The 0x41 initialize bit sequence 0x101 means:
enable memory power down function and special SDRAM clock
delay for synchronize SDRAM output and clock signal.

The 0x42 initialize squence 0x101 is wrong.  According to
the specification Bit 8 is reserved, thus not in use.
I removed it.

Signed-off-by: Jens Frederich <jfrederich@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/olpc_dcon/olpc_dcon.c b/drivers/staging/olpc_dcon/olpc_dcon.c
index 7c460f2c0d230565be67045b5f3b11b423295257..5ca4fa4fd246b9a11702493f28d12ef8f654d310 100644 (file)
--- a/drivers/staging/olpc_dcon/olpc_dcon.c
+++ b/drivers/staging/olpc_dcon/olpc_dcon.c
@@ -90,9 +90,10 @@ static int dcon_hw_init(struct dcon_priv *dcon, int is_init)
 
        /* SDRAM setup/hold time */
        dcon_write(dcon, 0x3a, 0xc040);
-       dcon_write(dcon, 0x41, 0x0000);
-       dcon_write(dcon, 0x41, 0x0101);
-       dcon_write(dcon, 0x42, 0x0101);
+       dcon_write(dcon, DCON_REG_MEM_OPT_A, 0x0000);  /* clear option bits */
+       dcon_write(dcon, DCON_REG_MEM_OPT_A,
+                               MEM_DLL_CLOCK_DELAY | MEM_POWER_DOWN);
+       dcon_write(dcon, DCON_REG_MEM_OPT_B, MEM_SOFT_RESET);
 
        /* Colour swizzle, AA, no passthrough, backlight */
        if (is_init) {
@@ -126,7 +127,7 @@ static int dcon_bus_stabilize(struct dcon_priv *dcon, int is_powered_down)
 power_up:
        if (is_powered_down) {
                x = 1;
-               x = olpc_ec_cmd(0x26, (unsigned char *)&x, 1, NULL, 0);
+               x = olpc_ec_cmd(EC_DCON_POWER_MODE, (u8 *)&x, 1, NULL, 0);
                if (x) {
                        pr_warn("unable to force dcon to power up: %d!\n", x);
                        return x;
@@ -144,7 +145,7 @@ power_up:
                pr_err("unable to stabilize dcon's smbus, reasserting power and praying.\n");
                BUG_ON(olpc_board_at_least(olpc_board(0xc2)));
                x = 0;
-               olpc_ec_cmd(0x26, (unsigned char *)&x, 1, NULL, 0);
+               olpc_ec_cmd(EC_DCON_POWER_MODE, (u8 *)&x, 1, NULL, 0);
                msleep(100);
                is_powered_down = 1;
                goto power_up;  /* argh, stupid hardware.. */
@@ -208,7 +209,7 @@ static void dcon_sleep(struct dcon_priv *dcon, bool sleep)
 
        if (sleep) {
                x = 0;
-               x = olpc_ec_cmd(0x26, (unsigned char *)&x, 1, NULL, 0);
+               x = olpc_ec_cmd(EC_DCON_POWER_MODE, (u8 *)&x, 1, NULL, 0);
                if (x)
                        pr_warn("unable to force dcon to power down: %d!\n", x);
                else

diff --git a/drivers/staging/olpc_dcon/olpc_dcon.h b/drivers/staging/olpc_dcon/olpc_dcon.h
index 997bded2949f2ccffe7cc6c0f1be50df4865a58b..524ee49fbacb4be70dd4d00847d9044bfffa84b3 100644 (file)
--- a/drivers/staging/olpc_dcon/olpc_dcon.h
+++ b/drivers/staging/olpc_dcon/olpc_dcon.h
@@ -22,15 +22,24 @@
 #define MODE_DEBUG     (1<<14)
 #define MODE_SELFTEST  (1<<15)
 
-#define DCON_REG_HRES          2
-#define DCON_REG_HTOTAL                3
-#define DCON_REG_HSYNC_WIDTH   4
-#define DCON_REG_VRES          5
-#define DCON_REG_VTOTAL                6
-#define DCON_REG_VSYNC_WIDTH   7
-#define DCON_REG_TIMEOUT       8
-#define DCON_REG_SCAN_INT      9
-#define DCON_REG_BRIGHT                10
+#define DCON_REG_HRES          0x2
+#define DCON_REG_HTOTAL                0x3
+#define DCON_REG_HSYNC_WIDTH   0x4
+#define DCON_REG_VRES          0x5
+#define DCON_REG_VTOTAL                0x6
+#define DCON_REG_VSYNC_WIDTH   0x7
+#define DCON_REG_TIMEOUT       0x8
+#define DCON_REG_SCAN_INT      0x9
+#define DCON_REG_BRIGHT                0x10
+#define DCON_REG_MEM_OPT_A     0x41
+#define DCON_REG_MEM_OPT_B     0x42
+
+/* Load Delay Locked Loop (DLL) settings for clock delay */
+#define MEM_DLL_CLOCK_DELAY    (1<<0)
+/* Memory controller power down function */
+#define MEM_POWER_DOWN         (1<<8)
+/* Memory controller software reset */
+#define MEM_SOFT_RESET         (1<<0)
 
 /* Status values */
 

diff --git a/include/linux/olpc-ec.h b/include/linux/olpc-ec.h
index 5bb6e760aa61220813ac8e1c29b47cf29660f37c..2925df3ce78a32a2e0c0130239fc3e51a74ca7f8 100644 (file)
--- a/include/linux/olpc-ec.h
+++ b/include/linux/olpc-ec.h
@@ -6,6 +6,7 @@
 #define EC_WRITE_SCI_MASK              0x1b
 #define EC_WAKE_UP_WLAN                        0x24
 #define EC_WLAN_LEAVE_RESET            0x25
+#define EC_DCON_POWER_MODE             0x26
 #define EC_READ_EB_MODE                        0x2a
 #define EC_SET_SCI_INHIBIT             0x32
 #define EC_SET_SCI_INHIBIT_RELEASE     0x34