x86: ich6_gpio: Add use-lvl-write-cache for I/O access mode

Add a device-tree property use-lvl-write-cache that will cause
writes to lvl to be cached instead of read from lvl before each
write. This is required on some platforms that have the register
implemented as dual read/write (such as Baytrail).

Prior to this fix the blue USB port on the Minnowboard Max was
unusable since USB_HOST_EN0 was set high then immediately set
low when USB_HOST_EN1 was written.

This also resolves the 'gpio clear | set' command warning like:
  "Warning: value of pin is still 0"

Signed-off-by: George McCollister <george.mccollister@gmail.com>
<rebased on latest origin/master, fixed all baytrail boards>
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/arch/x86/dts/bayleybay.dts b/arch/x86/dts/bayleybay.dts
index 18b310d39e884224fa0d37eea61ca06e0d0f86d9..1ae058d7a94f5b609f2f2920460accea3a736185 100644 (file)
--- a/arch/x86/dts/bayleybay.dts
+++ b/arch/x86/dts/bayleybay.dts
@@ -189,6 +189,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0 0x20>;
                                bank-name = "A";
+                               use-lvl-write-cache;
                        };
 
                        gpiob {
@@ -196,6 +197,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0x20 0x20>;
                                bank-name = "B";
+                               use-lvl-write-cache;
                        };
 
                        gpioc {
@@ -203,6 +205,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0x40 0x20>;
                                bank-name = "C";
+                               use-lvl-write-cache;
                        };
 
                        gpiod {
@@ -210,6 +213,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0x60 0x20>;
                                bank-name = "D";
+                               use-lvl-write-cache;
                        };
 
                        gpioe {
@@ -217,6 +221,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0x80 0x20>;
                                bank-name = "E";
+                               use-lvl-write-cache;
                        };
 
                        gpiof {
@@ -224,6 +229,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0xA0 0x20>;
                                bank-name = "F";
+                               use-lvl-write-cache;
                        };
                };
        };

diff --git a/arch/x86/dts/baytrail_som-db5800-som-6867.dts b/arch/x86/dts/baytrail_som-db5800-som-6867.dts
index e1d81a7283a5717e49857b12125c8a1aa75c687f..aa8bfb86513c4fa9571a548058616e911b445c45 100644 (file)
--- a/arch/x86/dts/baytrail_som-db5800-som-6867.dts
+++ b/arch/x86/dts/baytrail_som-db5800-som-6867.dts
@@ -212,6 +212,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0 0x20>;
                                bank-name = "A";
+                               use-lvl-write-cache;
                        };
 
                        gpiob {
@@ -219,6 +220,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0x20 0x20>;
                                bank-name = "B";
+                               use-lvl-write-cache;
                        };
 
                        gpioc {
@@ -226,6 +228,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0x40 0x20>;
                                bank-name = "C";
+                               use-lvl-write-cache;
                        };
 
                        gpiod {
@@ -233,6 +236,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0x60 0x20>;
                                bank-name = "D";
+                               use-lvl-write-cache;
                        };
 
                        gpioe {
@@ -240,6 +244,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0x80 0x20>;
                                bank-name = "E";
+                               use-lvl-write-cache;
                        };
 
                        gpiof {
@@ -247,6 +252,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0xA0 0x20>;
                                bank-name = "F";
+                               use-lvl-write-cache;
                        };
                };
        };

diff --git a/arch/x86/dts/conga-qeval20-qa3-e3845.dts b/arch/x86/dts/conga-qeval20-qa3-e3845.dts
index f0efe908e2c5b8d938e93319b7cc8937e3d21042..898e9c9b5f7537dae2e7fe8822f3307b9430e6c5 100644 (file)
--- a/arch/x86/dts/conga-qeval20-qa3-e3845.dts
+++ b/arch/x86/dts/conga-qeval20-qa3-e3845.dts
@@ -199,6 +199,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0 0x20>;
                                bank-name = "A";
+                               use-lvl-write-cache;
                        };
 
                        gpiob {
@@ -206,6 +207,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0x20 0x20>;
                                bank-name = "B";
+                               use-lvl-write-cache;
                        };
 
                        gpioc {
@@ -213,6 +215,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0x40 0x20>;
                                bank-name = "C";
+                               use-lvl-write-cache;
                        };
 
                        gpiod {
@@ -220,6 +223,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0x60 0x20>;
                                bank-name = "D";
+                               use-lvl-write-cache;
                        };
 
                        gpioe {
@@ -227,6 +231,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0x80 0x20>;
                                bank-name = "E";
+                               use-lvl-write-cache;
                        };
 
                        gpiof {
@@ -234,6 +239,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0xA0 0x20>;
                                bank-name = "F";
+                               use-lvl-write-cache;
                        };
                };
        };

diff --git a/arch/x86/dts/dfi-bt700.dtsi b/arch/x86/dts/dfi-bt700.dtsi
index 75ee6ade7c16e6e18a515600bb8b93b294e41217..546981a9ac1c38bd96756889a3a2ec314f096bba 100644 (file)
--- a/arch/x86/dts/dfi-bt700.dtsi
+++ b/arch/x86/dts/dfi-bt700.dtsi
@@ -201,6 +201,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0 0x20>;
                                bank-name = "A";
+                               use-lvl-write-cache;
                        };
 
                        gpiob {
@@ -208,6 +209,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0x20 0x20>;
                                bank-name = "B";
+                               use-lvl-write-cache;
                        };
 
                        gpioc {
@@ -215,6 +217,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0x40 0x20>;
                                bank-name = "C";
+                               use-lvl-write-cache;
                        };
 
                        gpiod {
@@ -222,6 +225,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0x60 0x20>;
                                bank-name = "D";
+                               use-lvl-write-cache;
                        };
 
                        gpioe {
@@ -229,6 +233,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0x80 0x20>;
                                bank-name = "E";
+                               use-lvl-write-cache;
                        };
 
                        gpiof {
@@ -236,6 +241,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0xA0 0x20>;
                                bank-name = "F";
+                               use-lvl-write-cache;
                        };
                };
        };

diff --git a/arch/x86/dts/minnowmax.dts b/arch/x86/dts/minnowmax.dts
index d51318bdf60757cf6ff4ad3026de4211fff2a1b4..bc382a89489ab27833f6f64087729458d38ed3db 100644 (file)
--- a/arch/x86/dts/minnowmax.dts
+++ b/arch/x86/dts/minnowmax.dts
@@ -218,6 +218,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0 0x20>;
                                bank-name = "A";
+                               use-lvl-write-cache;
                        };
 
                        gpiob {
@@ -225,6 +226,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0x20 0x20>;
                                bank-name = "B";
+                               use-lvl-write-cache;
                        };
 
                        gpioc {
@@ -232,6 +234,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0x40 0x20>;
                                bank-name = "C";
+                               use-lvl-write-cache;
                        };
 
                        gpiod {
@@ -239,6 +242,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0x60 0x20>;
                                bank-name = "D";
+                               use-lvl-write-cache;
                        };
 
                        gpioe {
@@ -246,6 +250,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0x80 0x20>;
                                bank-name = "E";
+                               use-lvl-write-cache;
                        };
 
                        gpiof {
@@ -253,6 +258,7 @@
                                u-boot,dm-pre-reloc;
                                reg = <0xA0 0x20>;
                                bank-name = "F";
+                               use-lvl-write-cache;
                        };
                };
        };

diff --git a/drivers/gpio/intel_ich6_gpio.c b/drivers/gpio/intel_ich6_gpio.c
index 8b782260bc336cd1117531820f0aedc1cc2ed31b..0a9eb03fd0500c9cfc7d3a1605dbf46ff11c1da9 100644 (file)
--- a/drivers/gpio/intel_ich6_gpio.c
+++ b/drivers/gpio/intel_ich6_gpio.c
@@ -46,22 +46,31 @@ struct ich6_bank_priv {
        uint16_t use_sel;
        uint16_t io_sel;
        uint16_t lvl;
+       u32 lvl_write_cache;
+       bool use_lvl_write_cache;
 };
 
 #define GPIO_USESEL_OFFSET(x)  (x)
 #define GPIO_IOSEL_OFFSET(x)   (x + 4)
 #define GPIO_LVL_OFFSET(x)     (x + 8)
 
-static int _ich6_gpio_set_value(uint16_t base, unsigned offset, int value)
+static int _ich6_gpio_set_value(struct ich6_bank_priv *bank, unsigned offset,
+                               int value)
 {
        u32 val;
 
-       val = inl(base);
+       if (bank->use_lvl_write_cache)
+               val = bank->lvl_write_cache;
+       else
+               val = inl(bank->lvl);
+
        if (value)
                val |= (1UL << offset);
        else
                val &= ~(1UL << offset);
-       outl(val, base);
+       outl(val, bank->lvl);
+       if (bank->use_lvl_write_cache)
+               bank->lvl_write_cache = val;
 
        return 0;
 }
@@ -112,6 +121,7 @@ static int ich6_gpio_probe(struct udevice *dev)
        struct ich6_bank_platdata *plat = dev_get_platdata(dev);
        struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
        struct ich6_bank_priv *bank = dev_get_priv(dev);
+       const void *prop;
 
        uc_priv->gpio_count = GPIO_PER_BANK;
        uc_priv->bank_name = plat->bank_name;
@@ -119,6 +129,14 @@ static int ich6_gpio_probe(struct udevice *dev)
        bank->io_sel = plat->base_addr + 4;
        bank->lvl = plat->base_addr + 8;
 
+       prop = fdt_getprop(gd->fdt_blob, dev->of_offset,
+                          "use-lvl-write-cache", NULL);
+       if (prop)
+               bank->use_lvl_write_cache = true;
+       else
+               bank->use_lvl_write_cache = false;
+       bank->lvl_write_cache = 0;
+
        return 0;
 }
 
@@ -160,7 +178,7 @@ static int ich6_gpio_direction_output(struct udevice *dev, unsigned offset,
        if (ret)
                return ret;
 
-       return _ich6_gpio_set_value(bank->lvl, offset, value);
+       return _ich6_gpio_set_value(bank, offset, value);
 }
 
 static int ich6_gpio_get_value(struct udevice *dev, unsigned offset)
@@ -170,6 +188,8 @@ static int ich6_gpio_get_value(struct udevice *dev, unsigned offset)
        int r;
 
        tmplong = inl(bank->lvl);
+       if (bank->use_lvl_write_cache)
+               tmplong |= bank->lvl_write_cache;
        r = (tmplong & (1UL << offset)) ? 1 : 0;
        return r;
 }
@@ -178,7 +198,7 @@ static int ich6_gpio_set_value(struct udevice *dev, unsigned offset,
                               int value)
 {
        struct ich6_bank_priv *bank = dev_get_priv(dev);
-       return _ich6_gpio_set_value(bank->lvl, offset, value);
+       return _ich6_gpio_set_value(bank, offset, value);
 }
 
 static int ich6_gpio_get_function(struct udevice *dev, unsigned offset)