Merge branch 'omap-pool'

[linux-2.6-omap-h63xx.git] / drivers / i2c / busses / i2c-s3c2410.c

diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index 5b7f95641ba48119d17fe71c7fc02b8c3b16fd2d..1691ef0f1ee1ee64dcd9352cf785849b26592623 100644 (file)
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -1,6 +1,6 @@
 /* linux/drivers/i2c/busses/i2c-s3c2410.c
  *
- * Copyright (C) 2004,2005 Simtec Electronics
+ * Copyright (C) 2004,2005,2009 Simtec Electronics
  *     Ben Dooks <ben@simtec.co.uk>
  *
  * S3C2410 I2C Controller
@@ -590,18 +590,6 @@ static int s3c24xx_i2c_calcdivisor(unsigned long clkin, unsigned int wanted,
        return clkin / (calc_divs * calc_div1);
 }
 
-/* freq_acceptable
- *
- * test wether a frequency is within the acceptable range of error
-*/
-
-static inline int freq_acceptable(unsigned int freq, unsigned int wanted)
-{
-       int diff = freq - wanted;
-
-       return diff >= -2 && diff <= 2;
-}
-
 /* s3c24xx_i2c_clockrate
  *
  * work out a divisor for the user requested frequency setting,
@@ -614,44 +602,28 @@ static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got)
        struct s3c2410_platform_i2c *pdata = i2c->dev->platform_data;
        unsigned long clkin = clk_get_rate(i2c->clk);
        unsigned int divs, div1;
+       unsigned long target_frequency;
        u32 iiccon;
        int freq;
-       int start, end;
 
        i2c->clkrate = clkin;
        clkin /= 1000;          /* clkin now in KHz */
 
-       dev_dbg(i2c->dev, "pdata %p, freq %lu %lu..%lu\n",
-                pdata, pdata->bus_freq, pdata->min_freq, pdata->max_freq);
-
-       if (pdata->bus_freq != 0) {
-               freq = s3c24xx_i2c_calcdivisor(clkin, pdata->bus_freq/1000,
-                                              &div1, &divs);
-               if (freq_acceptable(freq, pdata->bus_freq/1000))
-                       goto found;
-       }
-
-       /* ok, we may have to search for something suitable... */
+       dev_dbg(i2c->dev, "pdata desired frequency %lu\n", pdata->frequency);
 
-       start = (pdata->max_freq == 0) ? pdata->bus_freq : pdata->max_freq;
-       end = pdata->min_freq;
+       target_frequency = pdata->frequency ? pdata->frequency : 100000;
 
-       start /= 1000;
-       end /= 1000;
+       target_frequency /= 1000; /* Target frequency now in KHz */
 
-       /* search loop... */
+       freq = s3c24xx_i2c_calcdivisor(clkin, target_frequency, &div1, &divs);
 
-       for (; start > end; start--) {
-               freq = s3c24xx_i2c_calcdivisor(clkin, start, &div1, &divs);
-               if (freq_acceptable(freq, start))
-                       goto found;
+       if (freq > target_frequency) {
+               dev_err(i2c->dev,
+                       "Unable to achieve desired frequency %luKHz."   \
+                       " Lowest achievable %dKHz\n", target_frequency, freq);
+               return -EINVAL;
        }
 
-       /* cannot find frequency spec */
-
-       return -EINVAL;
-
- found:
        *got = freq;
 
        iiccon = readl(i2c->regs + S3C2410_IICCON);
@@ -663,6 +635,23 @@ static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got)
 
        writel(iiccon, i2c->regs + S3C2410_IICCON);
 
+       if (s3c24xx_i2c_is2440(i2c)) {
+               unsigned long sda_delay;
+
+               if (pdata->sda_delay) {
+                       sda_delay = (freq / 1000) * pdata->sda_delay;
+                       sda_delay /= 1000000;
+                       sda_delay = DIV_ROUND_UP(sda_delay, 5);
+                       if (sda_delay > 3)
+                               sda_delay = 3;
+                       sda_delay |= S3C2410_IICLC_FILTER_ON;
+               } else
+                       sda_delay = 0;
+
+               dev_dbg(i2c->dev, "IICLC=%08lx\n", sda_delay);
+               writel(sda_delay, i2c->regs + S3C2440_IICLC);
+       }
+
        return 0;
 }
 
@@ -769,11 +758,8 @@ static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c)
 
        /* check for s3c2440 i2c controller  */
 
-       if (s3c24xx_i2c_is2440(i2c)) {
-               dev_dbg(i2c->dev, "S3C2440_IICLC=%08x\n", pdata->sda_delay);
-
-               writel(pdata->sda_delay, i2c->regs + S3C2440_IICLC);
-       }
+       if (s3c24xx_i2c_is2440(i2c))
+               writel(0x0, i2c->regs + S3C2440_IICLC);
 
        return 0;
 }
@@ -1018,14 +1004,13 @@ static int __init i2c_adap_s3c_init(void)
 
        return ret;
 }
+subsys_initcall(i2c_adap_s3c_init);
 
 static void __exit i2c_adap_s3c_exit(void)
 {
        platform_driver_unregister(&s3c2410_i2c_driver);
        platform_driver_unregister(&s3c2440_i2c_driver);
 }
-
-module_init(i2c_adap_s3c_init);
 module_exit(i2c_adap_s3c_exit);
 
 MODULE_DESCRIPTION("S3C24XX I2C Bus driver");