[PATCH v2] i2c: (algo-pca) Fix mode selection for PCA9665

[PATCH v2] i2c: (algo-pca) Fix mode selection for PCA9665

[Guenter Roeck]

From: Thomas Kavanagh <tkavanagh-3r7Miqu9kMnR7s880joybQ@public.gmane.org>

The code currently always selects turbo mode for PCA9665, no matter which
clock frequency is configured. This is because it compares the clock frequency
against constants reflecting (boundary / 100). Compare against real boundary
frequencies to fix the problem.

Cc: Wolfram Sang <w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
Signed-off-by: Thomas Kavanagh <tkavanagh-3r7Miqu9kMnR7s880joybQ@public.gmane.org>
Signed-off-by: Guenter Roeck <groeck-3r7Miqu9kMnR7s880joybQ@public.gmane.org>
---
v2: Instead of changing the variable to compare against, change the clock values
    to compare against.

 drivers/i2c/algos/i2c-algo-pca.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/algos/i2c-algo-pca.c b/drivers/i2c/algos/i2c-algo-pca.c
index 07ccbef..f892a42 100644
--- a/drivers/i2c/algos/i2c-algo-pca.c
+++ b/drivers/i2c/algos/i2c-algo-pca.c
@@ -477,17 +477,17 @@ static int pca_init(struct i2c_adapter *adap)
 		/* To avoid integer overflow, use clock/100 for calculations */
 		clock = pca_clock(pca_data) / 100;
 
-		if (pca_data->i2c_clock > 10000) {
+		if (pca_data->i2c_clock > 1000000) {
 			mode = I2C_PCA_MODE_TURBO;
 			min_tlow = 14;
 			min_thi  = 5;
 			raise_fall_time = 22; /* Raise 11e-8s, Fall 11e-8s */
-		} else if (pca_data->i2c_clock > 4000) {
+		} else if (pca_data->i2c_clock > 400000) {
 			mode = I2C_PCA_MODE_FASTP;
 			min_tlow = 17;
 			min_thi  = 9;
 			raise_fall_time = 22; /* Raise 11e-8s, Fall 11e-8s */
-		} else if (pca_data->i2c_clock > 1000) {
+		} else if (pca_data->i2c_clock > 100000) {
 			mode = I2C_PCA_MODE_FAST;
 			min_tlow = 44;
 			min_thi  = 20;
-- 
1.7.9.7

Re: [PATCH v2] i2c: (algo-pca) Fix mode selection for PCA9665

[Wolfram Sang]

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On Thu, Sep 13, 2012 at 08:16:55AM -0700, Guenter Roeck wrote:
> From: Thomas Kavanagh <tkavanagh-3r7Miqu9kMnR7s880joybQ@public.gmane.org>
> 
> The code currently always selects turbo mode for PCA9665, no matter which
> clock frequency is configured. This is because it compares the clock frequency
> against constants reflecting (boundary / 100). Compare against real boundary
> frequencies to fix the problem.
> 
> Cc: Wolfram Sang <w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
> Signed-off-by: Thomas Kavanagh <tkavanagh-3r7Miqu9kMnR7s880joybQ@public.gmane.org>
> Signed-off-by: Guenter Roeck <groeck-3r7Miqu9kMnR7s880joybQ@public.gmane.org>
> ---
> v2: Instead of changing the variable to compare against, change the clock values
>     to compare against.

Applied to -current, thanks!

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