mpm: Add i2c APIs for simple transfers

1 files changed, 136 insertions, 0 deletions

diff --git a/mpm/lib/i2c/i2c_regs_iface.cpp b/mpm/lib/i2c/i2c_regs_iface.cpp
new file mode 100644
index 000000000..c476cf636
--- /dev/null
+++ b/mpm/lib/i2c/i2c_regs_iface.cpp
@@ -0,0 +1,136 @@
+//
+// Copyright 2018 Ettus Research, a National Instruments Company
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+//
+
+#include <mpm/types/regs_iface.hpp>
+#include <mpm/i2c/i2c_iface.hpp>
+#include <mpm/i2c/i2c_regs_iface.hpp>
+#include <mpm/exception.hpp>
+
+using mpm::types::regs_iface;
+
+/*! I2C implementation of the regs iface
+ *
+ * Uses i2cdev
+ */
+class i2c_regs_iface_impl : public regs_iface
+{
+public:
+
+    i2c_regs_iface_impl(
+        mpm::i2c::i2c_iface::sptr i2c_iface,
+        const size_t reg_addr_size
+    ) : _i2c_iface(i2c_iface),
+        _reg_addr_size(reg_addr_size)
+    {
+        if (reg_addr_size > 4) {
+            throw mpm::runtime_error("reg_addr_size too largs for i2c_regs_iface");
+        }
+    }
+
+    uint8_t peek8(
+        const uint32_t addr
+    ) {
+        uint8_t rx[1];
+        uint8_t tx[5];
+        int i = 0;
+        for (; i < _reg_addr_size; i++) {
+            tx[i] = 0xff & (addr >> 8*(_reg_addr_size-i-1));
+        }
+
+        int err = _i2c_iface->transfer(tx, _reg_addr_size, rx, 1);
+        if (err) {
+            throw mpm::runtime_error("I2C read failed");
+        }
+
+        return rx[0];
+    }
+
+    void poke8(
+        const uint32_t addr,
+        const uint8_t data
+    ) {
+        uint8_t tx[5];
+        int i = 0;
+        for (; i < _reg_addr_size; i++) {
+            tx[i] = 0xff & (addr >> 8*(_reg_addr_size-i-1));
+        }
+        tx[i] = data;
+
+        int err = _i2c_iface->transfer(tx, _reg_addr_size + 1, NULL, 0);
+        if (err) {
+            throw mpm::runtime_error("I2C write failed");
+        }
+    }
+
+    uint16_t peek16(
+        const uint32_t addr
+    ) {
+        uint8_t rx[2];
+        uint8_t tx[5];
+        int i = 0;
+        for (; i < _reg_addr_size; i++) {
+            tx[i] = 0xff & (addr >> 8*(_reg_addr_size-i-1));
+        }
+
+        int err = _i2c_iface->transfer(tx, _reg_addr_size, rx, 2);
+        if (err) {
+            throw mpm::runtime_error("I2C read failed");
+        }
+
+        uint16_t data = rx[0];
+        data = (data << 8) | rx[1];
+        return data;
+    }
+
+    void poke16(
+        const uint32_t addr,
+        const uint16_t data
+    ) {
+        uint8_t tx[6];
+        int i = 0;
+        for (; i < _reg_addr_size; i++) {
+            tx[i] = 0xff & (addr >> 8*(_reg_addr_size-i-1));
+        }
+        tx[i] = (data >> 8) & 0xff;
+        tx[i+1] = data & 0xff;
+
+        int err = _i2c_iface->transfer(tx, _reg_addr_size + 2, NULL, 0);
+        if (err) {
+            throw mpm::runtime_error("I2C write failed");
+        }
+    }
+
+private:
+    mpm::i2c::i2c_iface::sptr _i2c_iface;
+
+    const size_t _reg_addr_size;
+};
+
+regs_iface::sptr mpm::i2c::make_i2c_regs_iface(
+    mpm::i2c::i2c_iface::sptr i2c_iface,
+    const size_t reg_addr_size
+) {
+    return std::make_shared<i2c_regs_iface_impl>(
+        i2c_iface,
+        reg_addr_size
+    );
+}
+
+mpm::types::regs_iface::sptr mpm::i2c::make_i2cdev_regs_iface(
+    const std::string &bus,
+    const uint16_t addr,
+    const bool ten_bit_addr,
+    const int timeout_ms,
+    const size_t reg_addr_size
+) {
+    auto i2c_iface_sptr = mpm::i2c::i2c_iface::make_i2cdev(
+        bus, addr, ten_bit_addr, timeout_ms
+    );
+    return std::make_shared<i2c_regs_iface_impl>(
+        i2c_iface_sptr,
+        reg_addr_size
+    );
+}