src/devices/pci/drivers/amlogic-pcie/aml-pcie-clk.cc

// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Temporary Clock and PLL management until the clock protocol is fully
// developed.

#include "aml-pcie-clk.h"

#include <zircon/syscalls.h>

#include <hw/reg.h>
#include <hwreg/bitfields.h>
#include <hwreg/mmio.h>

#define AXG_MIPI_CNTL0 0xa5b80000

#define PCIE_PLL_CNTL0 (0x36 * 4)
#define PCIE_PLL_CNTL1 (0x37 * 4)
#define PCIE_PLL_CNTL2 (0x38 * 4)
#define PCIE_PLL_CNTL3 (0x39 * 4)
#define PCIE_PLL_CNTL4 (0x3A * 4)
#define PCIE_PLL_CNTL5 (0x3B * 4)
#define PCIE_PLL_CNTL6 (0x3C * 4)

#define AXG_PCIE_PLL_CNTL0 0x400106c8
#define AXG_PCIE_PLL_CNTL1 0x0084a2aa
#define AXG_PCIE_PLL_CNTL2 0xb75020be
#define AXG_PCIE_PLL_CNTL3 0x0a47488e
#define AXG_PCIE_PLL_CNTL4 0xc000004d
#define AXG_PCIE_PLL_CNTL5 0x00078000
#define AXG_PCIE_PLL_CNTL6 0x002323c6

#define MESON_PLL_ENABLE (1 << 30)
#define MESON_PLL_RESET (1 << 29)

class MesonPLLControl0 : public hwreg::RegisterBase<MesonPLLControl0, uint32_t> {
 public:
  DEF_FIELD(8, 0, m);
  DEF_FIELD(13, 9, n);
  DEF_FIELD(17, 16, od);
  DEF_BIT(29, reset);
  DEF_BIT(30, enable);
  DEF_BIT(31, lock);

  static auto Get() { return hwreg::RegisterAddr<MesonPLLControl0>(PCIE_PLL_CNTL0); }
};

class MesonPLLControl1 : public hwreg::RegisterBase<MesonPLLControl1, uint32_t> {
 public:
  DEF_FIELD(11, 0, div_frac);
  DEF_BIT(12, div_mode);
  DEF_FIELD(14, 13, dcvc_in);
  DEF_FIELD(16, 15, dco_sdmck_sel);
  DEF_BIT(17, dco_m_en);
  DEF_BIT(18, dco_band_opt);
  DEF_FIELD(21, 19, data_sel);
  DEF_FIELD(23, 22, afc_nt);
  DEF_FIELD(25, 24, afc_hold_t);
  DEF_FIELD(27, 26, afc_dsel_in);
  DEF_BIT(28, afc_dsel_bypass);
  DEF_BIT(29, afc_clk_sel);
  DEF_FIELD(31, 30, acq_r_ctr);

  static auto Get() { return hwreg::RegisterAddr<MesonPLLControl1>(PCIE_PLL_CNTL1); }
};

class MesonPLLControl6 : public hwreg::RegisterBase<MesonPLLControl6, uint32_t> {
 public:
  DEF_FIELD(7, 6, od2);
  DEF_BIT(2, cml_input_sel1);
  DEF_BIT(1, cml_input_sel0);
  DEF_BIT(0, cml_input_en);

  static auto Get() { return hwreg::RegisterAddr<MesonPLLControl6>(PCIE_PLL_CNTL6); }
};

zx_status_t PllSetRate(ddk::MmioBuffer* mmio) {
  // TODO(gkalsi): This statically configures the PCIe PLL to run at
  //               100mhz. When we write a real clock driver, we want this
  //               value to be configurable.

  mmio->Write32(AXG_MIPI_CNTL0, 0);
  mmio->Write32(AXG_PCIE_PLL_CNTL0, PCIE_PLL_CNTL0);
  mmio->Write32(AXG_PCIE_PLL_CNTL1, PCIE_PLL_CNTL1);
  mmio->Write32(AXG_PCIE_PLL_CNTL2, PCIE_PLL_CNTL2);
  mmio->Write32(AXG_PCIE_PLL_CNTL3, PCIE_PLL_CNTL3);
  mmio->Write32(AXG_PCIE_PLL_CNTL4, PCIE_PLL_CNTL4);
  mmio->Write32(AXG_PCIE_PLL_CNTL5, PCIE_PLL_CNTL5);
  mmio->Write32(AXG_PCIE_PLL_CNTL6, PCIE_PLL_CNTL6);

  auto cntl0 = MesonPLLControl0::Get().ReadFrom(mmio);

  cntl0.set_enable(1);
  cntl0.set_reset(0);
  cntl0.WriteTo(mmio);

  cntl0.set_m(200);
  cntl0.set_n(3);
  cntl0.set_od(1);
  cntl0.WriteTo(mmio);

  auto cntl1 = MesonPLLControl1::Get().ReadFrom(mmio);
  cntl1.set_div_frac(0);
  cntl1.WriteTo(mmio);

  auto cntl6 = MesonPLLControl6::Get().ReadFrom(mmio);
  cntl6.set_od2(3);
  cntl6.set_cml_input_sel1(1);
  cntl6.set_cml_input_sel0(1);
  cntl6.set_cml_input_en(1);
  cntl6.WriteTo(mmio);

  // Assert the Reset pin on the PLL
  cntl0.set_reset(1);
  cntl0.WriteTo(mmio);

  // Wait for the reset to take effect
  zx_nanosleep(zx_deadline_after(ZX_MSEC(10)));

  // De-assert the reset pin
  cntl0.set_reset(0);
  cntl0.WriteTo(mmio);

  // Wait for the PLL parameters to lock.
  const uint64_t kTimeout = 24000000;
  for (uint64_t attempts = 0; attempts < kTimeout; ++attempts) {
    auto cntl0 = MesonPLLControl0::Get().ReadFrom(mmio);

    // PLL has successfully locked?
    if (cntl0.lock())
      return ZX_OK;
  }

  return ZX_ERR_TIMED_OUT;
}