[4/4] ARM: dts: meson: consistently disable pin bias

Commit Message

Jerome Brunet Nov. 8, 2018, 10:44 a.m. UTC

On Amlogic chipsets, the bias set through pinconf applies to the pad
itself, not only the GPIO function. This means that even when we change
the function of the pad from GPIO to anything else, the bias previously
set still applies.

As we have seen with the eMMC, depending on the bias type and the function,
it may trigger problems.

The underlying issue is that we inherit whatever was left by previous user
of the pad (pinconf, u-boot or the ROM code). As a consequence, the actual
setup we will get is undefined.

There is nothing mentioned in the documentation about pad bias and pinmux
function, however leaving it undefined is not an option.

This change consistently disable the pad bias for every pinmux functions.
It seems to work well, we can only assume that the necessary bias (if any)
is already provided by the pin function itself.

Signed-off-by: Jerome Brunet <[e-mail]>
---
 arch/arm/boot/dts/meson8.dtsi   | 12 ++++++++++++
 arch/arm/boot/dts/meson8b.dtsi  |  9 +++++++++
 arch/arm/boot/dts/meson8m2.dtsi |  1 +
 3 files changed, 22 insertions(+)

Comments

kernel test robot Nov. 9, 2018, 1:49 p.m. UTC | #1

Hi Jerome,

I love your patch! Yet something to improve:

[auto build test ERROR on robh/for-next]
[also build test ERROR on v4.20-rc1 next-20181109]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Jerome-Brunet/ARM-dts-meson-set-pinmux-bias/20181109-065952
base:   https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next
config: arm-multi_v7_defconfig (attached as .config)
compiler: arm-linux-gnueabi-gcc (Debian 7.2.0-11) 7.2.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=7.2.0 make.cross ARCH=arm 

All errors (new ones prefixed by >>):

>> Error: arch/arm/boot/dts/meson8.dtsi:167.4-17 Properties must precede subnodes
   FATAL ERROR: Unable to parse input tree
--
>> Error: arch/arm/boot/dts/meson8b.dtsi:150.4-17 Properties must precede subnodes
   FATAL ERROR: Unable to parse input tree

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

Patch

diff --git a/arch/arm/boot/dts/meson8.dtsi b/arch/arm/boot/dts/meson8.dtsi
index 7162e0ca05b0..1e735c0d92e3 100644
--- a/arch/arm/boot/dts/meson8.dtsi
+++ b/arch/arm/boot/dts/meson8.dtsi
@@ -164,6 +164,7 @@ 
 				groups = "uart_tx_ao_a", "uart_rx_ao_a";
 				function = "uart_ao";
 			};
+			bias-disable;
 		};
 
 		i2c_ao_pins: i2c_mst_ao {
@@ -171,6 +172,7 @@ 
 				groups = "i2c_mst_sck_ao", "i2c_mst_sda_ao";
 				function = "i2c_mst_ao";
 			};
+			bias-disable;
 		};
 
 		ir_recv_pins: remote {
@@ -178,6 +180,7 @@ 
 				groups = "remote_input";
 				function = "remote";
 			};
+			bias-disable;
 		};
 
 		pwm_f_ao_pins: pwm-f-ao {
@@ -185,6 +188,7 @@ 
 				groups = "pwm_f_ao";
 				function = "pwm_f_ao";
 			};
+			bias-disable;
 		};
 	};
 };
@@ -239,6 +243,7 @@ 
 					"sd_d3_a", "sd_clk_a", "sd_cmd_a";
 				function = "sd_a";
 			};
+			bias-disable;
 		};
 
 		sd_b_pins: sd-b {
@@ -247,6 +252,7 @@ 
 					"sd_d3_b", "sd_clk_b", "sd_cmd_b";
 				function = "sd_b";
 			};
+			bias-disable;
 		};
 
 		sd_c_pins: sd-c {
@@ -255,6 +261,7 @@ 
 					"sd_d3_c", "sd_clk_c", "sd_cmd_c";
 				function = "sd_c";
 			};
+			bias-disable;
 		};
 
 		spi_nor_pins: nor {
@@ -262,6 +269,7 @@ 
 				groups = "nor_d", "nor_q", "nor_c", "nor_cs";
 				function = "nor";
 			};
+			bias-disable;
 		};
 
 		eth_pins: ethernet {
@@ -273,6 +281,7 @@ 
 					 "eth_mdc";
 				function = "ethernet";
 			};
+			bias-disable;
 		};
 
 		pwm_e_pins: pwm-e {
@@ -280,6 +289,7 @@ 
 				groups = "pwm_e";
 				function = "pwm_e";
 			};
+			bias-disable;
 		};
 
 		uart_a1_pins: uart-a1 {
@@ -288,6 +298,7 @@ 
 				       "uart_rx_a1";
 				function = "uart_a";
 			};
+			bias-disable;
 		};
 
 		uart_a1_cts_rts_pins: uart-a1-cts-rts {
@@ -296,6 +307,7 @@ 
 				       "uart_rts_a1";
 				function = "uart_a";
 			};
+			bias-disable;
 		};
 	};
 };
diff --git a/arch/arm/boot/dts/meson8b.dtsi b/arch/arm/boot/dts/meson8b.dtsi
index cd1ca9dda126..6fc129ab4453 100644
--- a/arch/arm/boot/dts/meson8b.dtsi
+++ b/arch/arm/boot/dts/meson8b.dtsi
@@ -147,6 +147,7 @@ 
 				groups = "uart_tx_ao_a", "uart_rx_ao_a";
 				function = "uart_ao";
 			};
+			bias-disable;
 		};
 
 		ir_recv_pins: remote {
@@ -154,6 +155,7 @@ 
 				groups = "remote_input";
 				function = "remote";
 			};
+			bias-disable;
 		};
 	};
 };
@@ -220,6 +222,7 @@ 
 					 "eth_txd2",
 					 "eth_txd3";
 				function = "ethernet";
+				bias-disable;
 			};
 		};
 
@@ -235,6 +238,7 @@ 
 					 "eth_mdio_en",
 					 "eth_mdc";
 				function = "ethernet";
+				bias-disable;
 			};
 		};
 
@@ -242,6 +246,7 @@ 
 			mux {
 				groups = "i2c_sda_a", "i2c_sck_a";
 				function = "i2c_a";
+				bias-disable;
 			};
 		};
 
@@ -250,6 +255,7 @@ 
 				groups = "sd_d0_b", "sd_d1_b", "sd_d2_b",
 					"sd_d3_b", "sd_clk_b", "sd_cmd_b";
 				function = "sd_b";
+				bias-disable;
 			};
 		};
 
@@ -257,6 +263,7 @@ 
 			mux {
 				groups = "pwm_c1";
 				function = "pwm_c";
+				bias-disable;
 			};
 		};
 
@@ -265,6 +272,7 @@ 
 				groups = "uart_tx_b0",
 				       "uart_rx_b0";
 				function = "uart_b";
+				bias-disable;
 			};
 		};
 
@@ -273,6 +281,7 @@ 
 				groups = "uart_cts_b0",
 				       "uart_rts_b0";
 				function = "uart_b";
+				bias-disable;
 			};
 		};
 	};
diff --git a/arch/arm/boot/dts/meson8m2.dtsi b/arch/arm/boot/dts/meson8m2.dtsi
index 3e1f92273d7b..d1a28c2adac5 100644
--- a/arch/arm/boot/dts/meson8m2.dtsi
+++ b/arch/arm/boot/dts/meson8m2.dtsi
@@ -45,6 +45,7 @@ 
 				 "eth_rxd1", "eth_rxd0",
 				 "eth_mdio", "eth_mdc";
 			function = "ethernet";
+			bias-disable;
 		};
 	};
 };