From adce42f39f75ac5d479d2b4caff73723107e0539 Mon Sep 17 00:00:00 2001
From: Erik Sejr <erik@eriks.ssimicro.com>
Date: Tue, 7 Jun 2016 20:58:17 -0400
Subject: [PATCH] Add ads1015 overlay

See: https://github.com/raspberrypi/linux/pull/1520
---
 arch/arm/boot/dts/overlays/Makefile            |  1 +
 arch/arm/boot/dts/overlays/README              | 22 ++++++
 arch/arm/boot/dts/overlays/ads1015-overlay.dts | 98 ++++++++++++++++++++++++++
 3 files changed, 121 insertions(+)
 create mode 100644 arch/arm/boot/dts/overlays/ads1015-overlay.dts

--- a/arch/arm/boot/dts/overlays/Makefile
+++ b/arch/arm/boot/dts/overlays/Makefile
@@ -13,6 +13,7 @@ ifeq ($(CONFIG_ARCH_BCM2835),y)
 endif
 
 dtbo-$(RPI_DT_OVERLAYS) += adau1977-adc.dtbo
+dtbo-$(RPI_DT_OVERLAYS) += ads1015.dtbo
 dtbo-$(RPI_DT_OVERLAYS) += ads7846.dtbo
 dtbo-$(RPI_DT_OVERLAYS) += akkordion-iqdacplus.dtbo
 dtbo-$(RPI_DT_OVERLAYS) += at86rf233.dtbo
--- a/arch/arm/boot/dts/overlays/README
+++ b/arch/arm/boot/dts/overlays/README
@@ -168,6 +168,28 @@ Load:   dtoverlay=adau1977-adc
 Params: <None>
 
 
+Name:   ads1015
+Info:   Overlay for activation of Texas Instruments ADS1015 ADC over I2C
+Load:   dtoverlay=ads1015,<param>=<val>
+Params: addr                    I2C bus address of device. Set based on how the
+                                addr pin is wired. (default=0x48 assumes addr
+                                is pulled to GND)
+        cha_enable              Enable virtual channel a. (default=true)
+        cha_cfg                 Set the configuration for virtual channel a.
+                                (default=4 configures this channel for the
+                                voltage at A0 with respect to GND)
+        cha_datarate            Set the datarate (samples/sec) for this channel.
+                                (default=4 sets 1600 sps)
+        cha_gain                Set the gain of the Programmable Gain
+                                Amplifier for this channel. (default=2 sets the
+                                full scale of the channel to 2.048 Volts)
+
+        Channel (ch) parameters can be set for each enabled channel.
+        A maximum of 4 channels can be enabled (letters a thru d).
+        For more information refer to the device datasheet at:
+        http://www.ti.com/lit/ds/symlink/ads1015.pdf
+
+
 Name:   ads7846
 Info:   ADS7846 Touch controller
 Load:   dtoverlay=ads7846,<param>=<val>
--- /dev/null
+++ b/arch/arm/boot/dts/overlays/ads1015-overlay.dts
@@ -0,0 +1,98 @@
+/*
+ * 2016 - Erik Sejr
+ */
+/dts-v1/;
+/plugin/;
+
+/ {
+    compatible = "brcm,bcm2708";
+    /* ----------- ADS1015 ------------ */
+    fragment@0 {
+        target = <&i2c_arm>;
+        __overlay__ {
+            #address-cells = <1>;
+            #size-cells = <0>;
+            status = "okay";
+            ads1015: ads1015 {
+                compatible = "ti,ads1015";
+                status = "okay";
+                #address-cells = <1>;
+                #size-cells = <0>;
+                reg = <0x48>;
+            };
+        };
+    };
+
+    fragment@1 {
+        target-path = "i2c_arm/ads1015";
+        __overlay__ {
+            #address-cells = <1>;
+            #size-cells = <0>;
+            channel_a: channel_a {
+                reg = <4>;
+                ti,gain = <2>;
+                ti,datarate = <4>;
+            };
+        };
+    };
+
+    fragment@2 {
+        target-path = "i2c_arm/ads1015";
+        __dormant__ {
+            #address-cells = <1>;
+            #size-cells = <0>;
+            channel_b: channel_b {
+                reg = <5>;
+                ti,gain = <2>;
+                ti,datarate = <4>;
+            };
+        };
+    };
+
+    fragment@3 {
+        target-path = "i2c_arm/ads1015";
+        __dormant__ {
+            #address-cells = <1>;
+            #size-cells = <0>;
+            channel_c: channel_c {
+                reg = <6>;
+                ti,gain = <2>;
+                ti,datarate = <4>;
+            };
+        };
+    };
+
+    fragment@4 {
+        target-path = "i2c_arm/ads1015";
+        __dormant__ {
+            #address-cells = <1>;
+            #size-cells = <0>;
+            channel_d: channel_d {
+                reg = <7>;
+                ti,gain = <2>;
+                ti,datarate = <4>;
+            };
+        };
+    };
+
+    __overrides__ {
+        addr =            <&ads1015>,"reg:0";
+        cha_enable =      <0>,"=1";
+        cha_cfg =         <&channel_a>,"reg:0";
+        cha_gain =        <&channel_a>,"ti,gain:0";
+        cha_datarate =    <&channel_a>,"ti,datarate:0";
+        chb_enable =      <0>,"=2";
+        chb_cfg =         <&channel_b>,"reg:0";
+        chb_gain =        <&channel_b>,"ti,gain:0";
+        chb_datarate =    <&channel_b>,"ti,datarate:0";
+        chc_enable =      <0>,"=3";
+        chc_cfg =         <&channel_c>,"reg:0";
+        chc_gain =        <&channel_c>,"ti,gain:0";
+        chc_datarate =    <&channel_c>,"ti,datarate:0";
+        chd_enable =      <0>,"=4";
+        chd_cfg =         <&channel_d>,"reg:0";
+        chd_gain =        <&channel_d>,"ti,gain:0";
+        chd_datarate =    <&channel_d>,"ti,datarate:0";
+   };
+
+};