diff options
| author | Alex Deucher <alexdeucher@gmail.com> | 2010-03-12 12:55:34 -0500 |
|---|---|---|
| committer | Dave Airlie <airlied@redhat.com> | 2010-03-15 09:58:34 +1000 |
| commit | 96a4c8d50de20da865296a380b996f73204d6b34 (patch) | |
| tree | 69c525d8f3165e6c39fa526bb4d8dd451112a04e /drivers/gpu/drm/radeon/radeon_i2c.c | |
| parent | ae08819c2a4729444676f1bb55e5e28263f6f5a1 (diff) | |
drm/radeon/kms: fix i2c prescale calc on older radeons
Should fix fdo bug 26430
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'drivers/gpu/drm/radeon/radeon_i2c.c')
| -rw-r--r-- | drivers/gpu/drm/radeon/radeon_i2c.c | 17 |
1 files changed, 8 insertions, 9 deletions
diff --git a/drivers/gpu/drm/radeon/radeon_i2c.c b/drivers/gpu/drm/radeon/radeon_i2c.c index 5d93418f9fc..f007fcb1191 100644 --- a/drivers/gpu/drm/radeon/radeon_i2c.c +++ b/drivers/gpu/drm/radeon/radeon_i2c.c @@ -183,11 +183,10 @@ static void set_data(void *i2c_priv, int data) static u32 radeon_get_i2c_prescale(struct radeon_device *rdev) { - struct radeon_pll *spll = &rdev->clock.spll; u32 sclk = radeon_get_engine_clock(rdev); u32 prescale = 0; - u32 n, m; - u8 loop; + u32 nm; + u8 n, m, loop; int i2c_clock; switch (rdev->family) { @@ -203,13 +202,15 @@ static u32 radeon_get_i2c_prescale(struct radeon_device *rdev) case CHIP_R300: case CHIP_R350: case CHIP_RV350: - n = (spll->reference_freq) / (4 * 6); + i2c_clock = 60; + nm = (sclk * 10) / (i2c_clock * 4); for (loop = 1; loop < 255; loop++) { - if ((loop * (loop - 1)) > n) + if ((nm / loop) < loop) break; } - m = loop - 1; - prescale = m | (loop << 8); + n = loop - 1; + m = loop - 2; + prescale = m | (n << 8); break; case CHIP_RV380: case CHIP_RS400: @@ -217,7 +218,6 @@ static u32 radeon_get_i2c_prescale(struct radeon_device *rdev) case CHIP_R420: case CHIP_R423: case CHIP_RV410: - sclk = radeon_get_engine_clock(rdev); prescale = (((sclk * 10)/(4 * 128 * 100) + 1) << 8) + 128; break; case CHIP_RS600: @@ -232,7 +232,6 @@ static u32 radeon_get_i2c_prescale(struct radeon_device *rdev) case CHIP_RV570: case CHIP_R580: i2c_clock = 50; - sclk = radeon_get_engine_clock(rdev); if (rdev->family == CHIP_R520) prescale = (127 << 8) + ((sclk * 10) / (4 * 127 * i2c_clock)); else |