Merge branch 'lpc32xx/drivers' into next/drivers

* lpc32xx/drivers: (566 commits)
  ARM: LPC32xx: ADC support for mach-lpc32xx

Includes an update to Linux 3.3-rc4

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 25 insertions, 10 deletions

diff --git a/drivers/gpu/drm/radeon/r600_blit_kms.c b/drivers/gpu/drm/radeon/r600_blit_kms.c
index d996f4381130..accc032c103f 100644
--- a/drivers/gpu/drm/radeon/r600_blit_kms.c
+++ b/drivers/gpu/drm/radeon/r600_blit_kms.c
@@ -468,27 +468,42 @@ set_default_state(struct radeon_device *rdev)
         radeon_ring_write(ring, sq_stack_resource_mgmt_2);
 }
 
+#define I2F_MAX_BITS 15
+#define I2F_MAX_INPUT  ((1 << I2F_MAX_BITS) - 1)
+#define I2F_SHIFT (24 - I2F_MAX_BITS)
+
+/*
+ * Converts unsigned integer into 32-bit IEEE floating point representation.
+ * Conversion is not universal and only works for the range from 0
+ * to 2^I2F_MAX_BITS-1. Currently we only use it with inputs between
+ * 0 and 16384 (inclusive), so I2F_MAX_BITS=15 is enough. If necessary,
+ * I2F_MAX_BITS can be increased, but that will add to the loop iterations
+ * and slow us down. Conversion is done by shifting the input and counting
+ * down until the first 1 reaches bit position 23. The resulting counter
+ * and the shifted input are, respectively, the exponent and the fraction.
+ * The sign is always zero.
+ */
 static uint32_t i2f(uint32_t input)
 {
         u32 result, i, exponent, fraction;
 
-        if ((input & 0x3fff) == 0)
-                result = 0; /* 0 is a special case */
+        WARN_ON_ONCE(input > I2F_MAX_INPUT);
+
+        if ((input & I2F_MAX_INPUT) == 0)
+                result = 0;
         else {
-                exponent = 140; /* exponent biased by 127; */
-                fraction = (input & 0x3fff) << 10; /* cheat and only
-                                                      handle numbers below 2^^15 */
-                for (i = 0; i < 14; i++) {
+                exponent = 126 + I2F_MAX_BITS;
+                fraction = (input & I2F_MAX_INPUT) << I2F_SHIFT;
+
+                for (i = 0; i < I2F_MAX_BITS; i++) {
                         if (fraction & 0x800000)
                                 break;
                         else {
-                                fraction = fraction << 1; /* keep
-                                                             shifting left until top bit = 1 */
+                                fraction = fraction << 1;
                                 exponent = exponent - 1;
                         }
                 }
-                result = exponent << 23 | (fraction & 0x7fffff); /* mask
-                                                                    off top bit; assumed 1 */
+                result = exponent << 23 | (fraction & 0x7fffff);
         }
         return result;
 }