i2c: designware: Enable high speed mode

This patch enabled high speed mode. High speed mode can be turn on by
setting the clk_freq to 3400000. High speed HCNT and LCNT are needed
as there is no default value provided.

Signed-off-by: Weifeng Voon <weifeng.voon@intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index 07edff7..c5783ed 100644 (file)
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -42,6 +42,8 @@
 #define DW_IC_SS_SCL_LCNT      0x18
 #define DW_IC_FS_SCL_HCNT      0x1c
 #define DW_IC_FS_SCL_LCNT      0x20
+#define DW_IC_HS_SCL_HCNT      0x24
+#define DW_IC_HS_SCL_LCNT      0x28
 #define DW_IC_INTR_STAT                0x2c
 #define DW_IC_INTR_MASK                0x30
 #define DW_IC_RAW_INTR_STAT    0x34
@@ -95,6 +97,9 @@
 
 #define DW_IC_TAR_10BITADDR_MASTER BIT(12)
 
+#define DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH     (BIT(2) | BIT(3))
+#define DW_IC_COMP_PARAM_1_SPEED_MODE_MASK     GENMASK(3, 2)
+
 /*
  * status codes
  */
@@ -293,7 +298,7 @@ static unsigned long i2c_dw_clk_rate(struct dw_i2c_dev *dev)
 int i2c_dw_init(struct dw_i2c_dev *dev)
 {
        u32 hcnt, lcnt;
-       u32 reg;
+       u32 reg, comp_param1;
        u32 sda_falling_time, scl_falling_time;
        int ret;
 
@@ -320,6 +325,8 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
                return -ENODEV;
        }
 
+       comp_param1 = dw_readl(dev, DW_IC_COMP_PARAM_1);
+
        /* Disable the adapter */
        __i2c_dw_enable(dev, false);
 
@@ -369,6 +376,23 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
        dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT);
        dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
 
+       if ((dev->master_cfg & DW_IC_CON_SPEED_MASK) ==
+               DW_IC_CON_SPEED_HIGH) {
+               if ((comp_param1 & DW_IC_COMP_PARAM_1_SPEED_MODE_MASK)
+                       != DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH) {
+                       dev_err(dev->dev, "High Speed not supported!\n");
+                       dev->master_cfg &= ~DW_IC_CON_SPEED_MASK;
+                       dev->master_cfg |= DW_IC_CON_SPEED_FAST;
+               } else if (dev->hs_hcnt && dev->hs_lcnt) {
+                       hcnt = dev->hs_hcnt;
+                       lcnt = dev->hs_lcnt;
+                       dw_writel(dev, hcnt, DW_IC_HS_SCL_HCNT);
+                       dw_writel(dev, lcnt, DW_IC_HS_SCL_LCNT);
+                       dev_dbg(dev->dev, "HighSpeed-mode HCNT:LCNT = %d:%d\n",
+                               hcnt, lcnt);
+               }
+       }
+
        /* Configure SDA Hold Time if required */
        if (dev->sda_hold_time) {
                reg = dw_readl(dev, DW_IC_COMP_VERSION);

diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index 84866db..22bfbe1 100644 (file)
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -26,6 +26,7 @@
 #define DW_IC_CON_MASTER               0x1
 #define DW_IC_CON_SPEED_STD            0x2
 #define DW_IC_CON_SPEED_FAST           0x4
+#define DW_IC_CON_SPEED_HIGH           0x6
 #define DW_IC_CON_SPEED_MASK           0x6
 #define DW_IC_CON_10BITADDR_MASTER     0x10
 #define DW_IC_CON_RESTART_EN           0x20

diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index d45481e..cb846cb 100644 (file)
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -197,12 +197,12 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 
        /*
         * Only standard mode at 100kHz, fast mode at 400kHz,
-        * and fast mode plus at 1MHz are supported.
+        * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported.
         */
        if (dev->clk_freq != 100000 && dev->clk_freq != 400000
-           && dev->clk_freq != 1000000) {
+           && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) {
                dev_err(&pdev->dev,
-                       "Only 100kHz, 400kHz and 1MHz are supported");
+                       "Only 100kHz, 400kHz, 1MHz and 3.4MHz supported");
                return -EINVAL;
        }
 
@@ -221,10 +221,16 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
        dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
                          DW_IC_CON_RESTART_EN;
 
-       if (dev->clk_freq == 100000)
+       switch (dev->clk_freq) {
+       case 100000:
                dev->master_cfg |= DW_IC_CON_SPEED_STD;
-       else
+               break;
+       case 3400000:
+               dev->master_cfg |= DW_IC_CON_SPEED_HIGH;
+               break;
+       default:
                dev->master_cfg |= DW_IC_CON_SPEED_FAST;
+       }
 
        dev->clk = devm_clk_get(&pdev->dev, NULL);
        if (!i2c_dw_plat_prepare_clk(dev, true)) {