i2c: designware_i2c: Put hold config in a struct

Create a struct to hold the three timing parameters. This will make it
easier to move these calculations into a separate function in a later
patch.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heiko Schocher <hs@denx.de>

diff --git a/drivers/i2c/designware_i2c.c b/drivers/i2c/designware_i2c.c
index 6e5545c..e50987a 100644 (file)
--- a/drivers/i2c/designware_i2c.c
+++ b/drivers/i2c/designware_i2c.c
@@ -13,6 +13,23 @@
 #include <asm/io.h>
 #include "designware_i2c.h"
 
+/**
+ * struct dw_i2c_speed_config - timings to use for a particular speed
+ *
+ * This holds calculated values to be written to the I2C controller. Each value
+ * is represented as a number of IC clock cycles.
+ *
+ * @scl_lcnt: Low count value for SCL
+ * @scl_hcnt: High count value for SCL
+ * @sda_hold: Data hold count
+ */
+struct dw_i2c_speed_config {
+       /* SCL high and low period count */
+       uint scl_lcnt;
+       uint scl_hcnt;
+       uint sda_hold;
+};
+
 #ifdef CONFIG_SYS_I2C_DW_ENABLE_STATUS_UNSUPPORTED
 static int  dw_i2c_enable(struct i2c_regs *i2c_base, bool enable)
 {
@@ -58,10 +75,10 @@ static unsigned int __dw_i2c_set_bus_speed(struct dw_i2c *priv,
                                           unsigned int bus_clk)
 {
        const struct dw_scl_sda_cfg *scl_sda_cfg = NULL;
+       struct dw_i2c_speed_config config;
        ulong bus_khz = bus_clk / 1000;
        enum i2c_speed_mode i2c_spd;
        unsigned int cntl;
-       unsigned int hcnt, lcnt;
        unsigned int ena;
 
        if (priv)
@@ -83,53 +100,64 @@ static unsigned int __dw_i2c_set_bus_speed(struct dw_i2c *priv,
 
        cntl = (readl(&i2c_base->ic_con) & (~IC_CON_SPD_MSK));
 
+       config.scl_hcnt = 0;
+       config.scl_lcnt = 0;
+       config.sda_hold = 0;
+       if (scl_sda_cfg) {
+               config.sda_hold = scl_sda_cfg->sda_hold;
+               if (i2c_spd == IC_SPEED_MODE_STANDARD) {
+                       config.scl_hcnt = scl_sda_cfg->ss_hcnt;
+                       config.scl_lcnt = scl_sda_cfg->ss_lcnt;
+               } else {
+                       config.scl_hcnt = scl_sda_cfg->fs_hcnt;
+                       config.scl_lcnt = scl_sda_cfg->fs_lcnt;
+               }
+       }
+
        switch (i2c_spd) {
        case IC_SPEED_MODE_HIGH:
                cntl |= IC_CON_SPD_SS;
-               if (scl_sda_cfg) {
-                       hcnt = scl_sda_cfg->fs_hcnt;
-                       lcnt = scl_sda_cfg->fs_lcnt;
-               } else {
-                       hcnt = (bus_khz * MIN_HS_SCL_HIGHTIME) / NANO_TO_KILO;
-                       lcnt = (bus_khz * MIN_HS_SCL_LOWTIME) / NANO_TO_KILO;
+               if (!scl_sda_cfg) {
+                       config.scl_hcnt = (bus_khz * MIN_HS_SCL_HIGHTIME) /
+                                NANO_TO_KILO;
+                       config.scl_lcnt = (bus_khz * MIN_HS_SCL_LOWTIME) /
+                                NANO_TO_KILO;
                }
-               writel(hcnt, &i2c_base->ic_hs_scl_hcnt);
-               writel(lcnt, &i2c_base->ic_hs_scl_lcnt);
+               writel(config.scl_hcnt, &i2c_base->ic_hs_scl_hcnt);
+               writel(config.scl_lcnt, &i2c_base->ic_hs_scl_lcnt);
                break;
 
        case IC_SPEED_MODE_STANDARD:
                cntl |= IC_CON_SPD_SS;
-               if (scl_sda_cfg) {
-                       hcnt = scl_sda_cfg->ss_hcnt;
-                       lcnt = scl_sda_cfg->ss_lcnt;
-               } else {
-                       hcnt = (bus_khz * MIN_SS_SCL_HIGHTIME) / NANO_TO_KILO;
-                       lcnt = (bus_khz * MIN_SS_SCL_LOWTIME) / NANO_TO_KILO;
+               if (!scl_sda_cfg) {
+                       config.scl_hcnt = (bus_khz * MIN_SS_SCL_HIGHTIME) /
+                                NANO_TO_KILO;
+                       config.scl_lcnt = (bus_khz * MIN_SS_SCL_LOWTIME) /
+                                NANO_TO_KILO;
                }
-               writel(hcnt, &i2c_base->ic_ss_scl_hcnt);
-               writel(lcnt, &i2c_base->ic_ss_scl_lcnt);
+               writel(config.scl_hcnt, &i2c_base->ic_ss_scl_hcnt);
+               writel(config.scl_lcnt, &i2c_base->ic_ss_scl_lcnt);
                break;
 
        case IC_SPEED_MODE_FAST:
        default:
                cntl |= IC_CON_SPD_FS;
-               if (scl_sda_cfg) {
-                       hcnt = scl_sda_cfg->fs_hcnt;
-                       lcnt = scl_sda_cfg->fs_lcnt;
-               } else {
-                       hcnt = (bus_khz * MIN_FS_SCL_HIGHTIME) / NANO_TO_KILO;
-                       lcnt = (bus_khz * MIN_FS_SCL_LOWTIME) / NANO_TO_KILO;
+               if (!scl_sda_cfg) {
+                       config.scl_hcnt = (bus_khz * MIN_FS_SCL_HIGHTIME) /
+                                NANO_TO_KILO;
+                       config.scl_lcnt = (bus_khz * MIN_FS_SCL_LOWTIME) /
+                                NANO_TO_KILO;
                }
-               writel(hcnt, &i2c_base->ic_fs_scl_hcnt);
-               writel(lcnt, &i2c_base->ic_fs_scl_lcnt);
+               writel(config.scl_hcnt, &i2c_base->ic_fs_scl_hcnt);
+               writel(config.scl_lcnt, &i2c_base->ic_fs_scl_lcnt);
                break;
        }
 
        writel(cntl, &i2c_base->ic_con);
 
        /* Configure SDA Hold Time if required */
-       if (scl_sda_cfg)
-               writel(scl_sda_cfg->sda_hold, &i2c_base->ic_sda_hold);
+       if (config.sda_hold)
+               writel(config.sda_hold, &i2c_base->ic_sda_hold);
 
        /* Restore back i2c now speed set */
        if (ena == IC_ENABLE_0B)