igc: Add code for PHY support

Add PHY's ID support
Add support for initialization, acquire and release of PHY
Enable register access

Signed-off-by: Sasha Neftin <sasha.neftin@intel.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 457 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/igc/igc_phy.c b/drivers/net/ethernet/intel/igc/igc_phy.c
new file mode 100644
index 000000000000..88583c1d4970
--- /dev/null
+++ b/drivers/net/ethernet/intel/igc/igc_phy.c
@@ -0,0 +1,457 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c)  2018 Intel Corporation */
+
+#include "igc_phy.h"
+
+/**
+ * igc_check_reset_block - Check if PHY reset is blocked
+ * @hw: pointer to the HW structure
+ *
+ * Read the PHY management control register and check whether a PHY reset
+ * is blocked.  If a reset is not blocked return 0, otherwise
+ * return IGC_ERR_BLK_PHY_RESET (12).
+ */
+s32 igc_check_reset_block(struct igc_hw *hw)
+{
+	u32 manc;
+
+	manc = rd32(IGC_MANC);
+
+	return (manc & IGC_MANC_BLK_PHY_RST_ON_IDE) ?
+		IGC_ERR_BLK_PHY_RESET : 0;
+}
+
+/**
+ * igc_get_phy_id - Retrieve the PHY ID and revision
+ * @hw: pointer to the HW structure
+ *
+ * Reads the PHY registers and stores the PHY ID and possibly the PHY
+ * revision in the hardware structure.
+ */
+s32 igc_get_phy_id(struct igc_hw *hw)
+{
+	struct igc_phy_info *phy = &hw->phy;
+	s32 ret_val = 0;
+	u16 phy_id;
+
+	ret_val = phy->ops.read_reg(hw, PHY_ID1, &phy_id);
+	if (ret_val)
+		goto out;
+
+	phy->id = (u32)(phy_id << 16);
+	usleep_range(200, 500);
+	ret_val = phy->ops.read_reg(hw, PHY_ID2, &phy_id);
+	if (ret_val)
+		goto out;
+
+	phy->id |= (u32)(phy_id & PHY_REVISION_MASK);
+	phy->revision = (u32)(phy_id & ~PHY_REVISION_MASK);
+
+out:
+	return ret_val;
+}
+
+/**
+ * igc_phy_has_link - Polls PHY for link
+ * @hw: pointer to the HW structure
+ * @iterations: number of times to poll for link
+ * @usec_interval: delay between polling attempts
+ * @success: pointer to whether polling was successful or not
+ *
+ * Polls the PHY status register for link, 'iterations' number of times.
+ */
+s32 igc_phy_has_link(struct igc_hw *hw, u32 iterations,
+		     u32 usec_interval, bool *success)
+{
+	u16 i, phy_status;
+	s32 ret_val = 0;
+
+	for (i = 0; i < iterations; i++) {
+		/* Some PHYs require the PHY_STATUS register to be read
+		 * twice due to the link bit being sticky.  No harm doing
+		 * it across the board.
+		 */
+		ret_val = hw->phy.ops.read_reg(hw, PHY_STATUS, &phy_status);
+		if (ret_val && usec_interval > 0) {
+			/* If the first read fails, another entity may have
+			 * ownership of the resources, wait and try again to
+			 * see if they have relinquished the resources yet.
+			 */
+			if (usec_interval >= 1000)
+				mdelay(usec_interval / 1000);
+			else
+				udelay(usec_interval);
+		}
+		ret_val = hw->phy.ops.read_reg(hw, PHY_STATUS, &phy_status);
+		if (ret_val)
+			break;
+		if (phy_status & MII_SR_LINK_STATUS)
+			break;
+		if (usec_interval >= 1000)
+			mdelay(usec_interval / 1000);
+		else
+			udelay(usec_interval);
+	}
+
+	*success = (i < iterations) ? true : false;
+
+	return ret_val;
+}
+
+/**
+ * igc_power_up_phy_copper - Restore copper link in case of PHY power down
+ * @hw: pointer to the HW structure
+ *
+ * In the case of a PHY power down to save power, or to turn off link during a
+ * driver unload, restore the link to previous settings.
+ */
+void igc_power_up_phy_copper(struct igc_hw *hw)
+{
+	u16 mii_reg = 0;
+
+	/* The PHY will retain its settings across a power down/up cycle */
+	hw->phy.ops.read_reg(hw, PHY_CONTROL, &mii_reg);
+	mii_reg &= ~MII_CR_POWER_DOWN;
+	hw->phy.ops.write_reg(hw, PHY_CONTROL, mii_reg);
+}
+
+/**
+ * igc_power_down_phy_copper - Power down copper PHY
+ * @hw: pointer to the HW structure
+ *
+ * Power down PHY to save power when interface is down and wake on lan
+ * is not enabled.
+ */
+void igc_power_down_phy_copper(struct igc_hw *hw)
+{
+	u16 mii_reg = 0;
+
+	/* The PHY will retain its settings across a power down/up cycle */
+	hw->phy.ops.read_reg(hw, PHY_CONTROL, &mii_reg);
+	mii_reg |= MII_CR_POWER_DOWN;
+
+	/* Temporary workaround - should be removed when PHY will implement
+	 * IEEE registers as properly
+	 */
+	/* hw->phy.ops.write_reg(hw, PHY_CONTROL, mii_reg);*/
+	usleep_range(1000, 2000);
+}
+
+/**
+ * igc_check_downshift - Checks whether a downshift in speed occurred
+ * @hw: pointer to the HW structure
+ *
+ * Success returns 0, Failure returns 1
+ *
+ * A downshift is detected by querying the PHY link health.
+ */
+s32 igc_check_downshift(struct igc_hw *hw)
+{
+	struct igc_phy_info *phy = &hw->phy;
+	u16 phy_data, offset, mask;
+	s32 ret_val;
+
+	switch (phy->type) {
+	case igc_phy_i225:
+	default:
+		/* speed downshift not supported */
+		phy->speed_downgraded = false;
+		ret_val = 0;
+		goto out;
+	}
+
+	ret_val = phy->ops.read_reg(hw, offset, &phy_data);
+
+	if (!ret_val)
+		phy->speed_downgraded = (phy_data & mask) ? true : false;
+
+out:
+	return ret_val;
+}
+
+/**
+ * igc_phy_hw_reset - PHY hardware reset
+ * @hw: pointer to the HW structure
+ *
+ * Verify the reset block is not blocking us from resetting.  Acquire
+ * semaphore (if necessary) and read/set/write the device control reset
+ * bit in the PHY.  Wait the appropriate delay time for the device to
+ * reset and release the semaphore (if necessary).
+ */
+s32 igc_phy_hw_reset(struct igc_hw *hw)
+{
+	struct igc_phy_info *phy = &hw->phy;
+	s32  ret_val;
+	u32 ctrl;
+
+	ret_val = igc_check_reset_block(hw);
+	if (ret_val) {
+		ret_val = 0;
+		goto out;
+	}
+
+	ret_val = phy->ops.acquire(hw);
+	if (ret_val)
+		goto out;
+
+	ctrl = rd32(IGC_CTRL);
+	wr32(IGC_CTRL, ctrl | IGC_CTRL_PHY_RST);
+	wrfl();
+
+	udelay(phy->reset_delay_us);
+
+	wr32(IGC_CTRL, ctrl);
+	wrfl();
+
+	usleep_range(1500, 2000);
+
+	phy->ops.release(hw);
+
+out:
+	return ret_val;
+}
+
+/**
+ * igc_read_phy_reg_mdic - Read MDI control register
+ * @hw: pointer to the HW structure
+ * @offset: register offset to be read
+ * @data: pointer to the read data
+ *
+ * Reads the MDI control register in the PHY at offset and stores the
+ * information read to data.
+ */
+static s32 igc_read_phy_reg_mdic(struct igc_hw *hw, u32 offset, u16 *data)
+{
+	struct igc_phy_info *phy = &hw->phy;
+	u32 i, mdic = 0;
+	s32 ret_val = 0;
+
+	if (offset > MAX_PHY_REG_ADDRESS) {
+		hw_dbg("PHY Address %d is out of range\n", offset);
+		ret_val = -IGC_ERR_PARAM;
+		goto out;
+	}
+
+	/* Set up Op-code, Phy Address, and register offset in the MDI
+	 * Control register.  The MAC will take care of interfacing with the
+	 * PHY to retrieve the desired data.
+	 */
+	mdic = ((offset << IGC_MDIC_REG_SHIFT) |
+		(phy->addr << IGC_MDIC_PHY_SHIFT) |
+		(IGC_MDIC_OP_READ));
+
+	wr32(IGC_MDIC, mdic);
+
+	/* Poll the ready bit to see if the MDI read completed
+	 * Increasing the time out as testing showed failures with
+	 * the lower time out
+	 */
+	for (i = 0; i < IGC_GEN_POLL_TIMEOUT; i++) {
+		usleep_range(500, 1000);
+		mdic = rd32(IGC_MDIC);
+		if (mdic & IGC_MDIC_READY)
+			break;
+	}
+	if (!(mdic & IGC_MDIC_READY)) {
+		hw_dbg("MDI Read did not complete\n");
+		ret_val = -IGC_ERR_PHY;
+		goto out;
+	}
+	if (mdic & IGC_MDIC_ERROR) {
+		hw_dbg("MDI Error\n");
+		ret_val = -IGC_ERR_PHY;
+		goto out;
+	}
+	*data = (u16)mdic;
+
+out:
+	return ret_val;
+}
+
+/**
+ * igc_write_phy_reg_mdic - Write MDI control register
+ * @hw: pointer to the HW structure
+ * @offset: register offset to write to
+ * @data: data to write to register at offset
+ *
+ * Writes data to MDI control register in the PHY at offset.
+ */
+static s32 igc_write_phy_reg_mdic(struct igc_hw *hw, u32 offset, u16 data)
+{
+	struct igc_phy_info *phy = &hw->phy;
+	u32 i, mdic = 0;
+	s32 ret_val = 0;
+
+	if (offset > MAX_PHY_REG_ADDRESS) {
+		hw_dbg("PHY Address %d is out of range\n", offset);
+		ret_val = -IGC_ERR_PARAM;
+		goto out;
+	}
+
+	/* Set up Op-code, Phy Address, and register offset in the MDI
+	 * Control register.  The MAC will take care of interfacing with the
+	 * PHY to write the desired data.
+	 */
+	mdic = (((u32)data) |
+		(offset << IGC_MDIC_REG_SHIFT) |
+		(phy->addr << IGC_MDIC_PHY_SHIFT) |
+		(IGC_MDIC_OP_WRITE));
+
+	wr32(IGC_MDIC, mdic);
+
+	/* Poll the ready bit to see if the MDI read completed
+	 * Increasing the time out as testing showed failures with
+	 * the lower time out
+	 */
+	for (i = 0; i < IGC_GEN_POLL_TIMEOUT; i++) {
+		usleep_range(500, 1000);
+		mdic = rd32(IGC_MDIC);
+		if (mdic & IGC_MDIC_READY)
+			break;
+	}
+	if (!(mdic & IGC_MDIC_READY)) {
+		hw_dbg("MDI Write did not complete\n");
+		ret_val = -IGC_ERR_PHY;
+		goto out;
+	}
+	if (mdic & IGC_MDIC_ERROR) {
+		hw_dbg("MDI Error\n");
+		ret_val = -IGC_ERR_PHY;
+		goto out;
+	}
+
+out:
+	return ret_val;
+}
+
+/**
+ * __igc_access_xmdio_reg - Read/write XMDIO register
+ * @hw: pointer to the HW structure
+ * @address: XMDIO address to program
+ * @dev_addr: device address to program
+ * @data: pointer to value to read/write from/to the XMDIO address
+ * @read: boolean flag to indicate read or write
+ */
+static s32 __igc_access_xmdio_reg(struct igc_hw *hw, u16 address,
+				  u8 dev_addr, u16 *data, bool read)
+{
+	s32 ret_val;
+
+	ret_val = hw->phy.ops.write_reg(hw, IGC_MMDAC, dev_addr);
+	if (ret_val)
+		return ret_val;
+
+	ret_val = hw->phy.ops.write_reg(hw, IGC_MMDAAD, address);
+	if (ret_val)
+		return ret_val;
+
+	ret_val = hw->phy.ops.write_reg(hw, IGC_MMDAC, IGC_MMDAC_FUNC_DATA |
+					dev_addr);
+	if (ret_val)
+		return ret_val;
+
+	if (read)
+		ret_val = hw->phy.ops.read_reg(hw, IGC_MMDAAD, data);
+	else
+		ret_val = hw->phy.ops.write_reg(hw, IGC_MMDAAD, *data);
+	if (ret_val)
+		return ret_val;
+
+	/* Recalibrate the device back to 0 */
+	ret_val = hw->phy.ops.write_reg(hw, IGC_MMDAC, 0);
+	if (ret_val)
+		return ret_val;
+
+	return ret_val;
+}
+
+/**
+ * igc_read_xmdio_reg - Read XMDIO register
+ * @hw: pointer to the HW structure
+ * @addr: XMDIO address to program
+ * @dev_addr: device address to program
+ * @data: value to be read from the EMI address
+ */
+static s32 igc_read_xmdio_reg(struct igc_hw *hw, u16 addr,
+			      u8 dev_addr, u16 *data)
+{
+	return __igc_access_xmdio_reg(hw, addr, dev_addr, data, true);
+}
+
+/**
+ * igc_write_xmdio_reg - Write XMDIO register
+ * @hw: pointer to the HW structure
+ * @addr: XMDIO address to program
+ * @dev_addr: device address to program
+ * @data: value to be written to the XMDIO address
+ */
+static s32 igc_write_xmdio_reg(struct igc_hw *hw, u16 addr,
+			       u8 dev_addr, u16 data)
+{
+	return __igc_access_xmdio_reg(hw, addr, dev_addr, &data, false);
+}
+
+/**
+ * igc_write_phy_reg_gpy - Write GPY PHY register
+ * @hw: pointer to the HW structure
+ * @offset: register offset to write to
+ * @data: data to write at register offset
+ *
+ * Acquires semaphore, if necessary, then writes the data to PHY register
+ * at the offset. Release any acquired semaphores before exiting.
+ */
+s32 igc_write_phy_reg_gpy(struct igc_hw *hw, u32 offset, u16 data)
+{
+	u8 dev_addr = (offset & GPY_MMD_MASK) >> GPY_MMD_SHIFT;
+	s32 ret_val;
+
+	offset = offset & GPY_REG_MASK;
+
+	if (!dev_addr) {
+		ret_val = hw->phy.ops.acquire(hw);
+		if (ret_val)
+			return ret_val;
+		ret_val = igc_write_phy_reg_mdic(hw, offset, data);
+		if (ret_val)
+			return ret_val;
+		hw->phy.ops.release(hw);
+	} else {
+		ret_val = igc_write_xmdio_reg(hw, (u16)offset, dev_addr,
+					      data);
+	}
+
+	return ret_val;
+}
+
+/**
+ * igc_read_phy_reg_gpy - Read GPY PHY register
+ * @hw: pointer to the HW structure
+ * @offset: lower half is register offset to read to
+ * upper half is MMD to use.
+ * @data: data to read at register offset
+ *
+ * Acquires semaphore, if necessary, then reads the data in the PHY register
+ * at the offset. Release any acquired semaphores before exiting.
+ */
+s32 igc_read_phy_reg_gpy(struct igc_hw *hw, u32 offset, u16 *data)
+{
+	u8 dev_addr = (offset & GPY_MMD_MASK) >> GPY_MMD_SHIFT;
+	s32 ret_val;
+
+	offset = offset & GPY_REG_MASK;
+
+	if (!dev_addr) {
+		ret_val = hw->phy.ops.acquire(hw);
+		if (ret_val)
+			return ret_val;
+		ret_val = igc_read_phy_reg_mdic(hw, offset, data);
+		if (ret_val)
+			return ret_val;
+		hw->phy.ops.release(hw);
+	} else {
+		ret_val = igc_read_xmdio_reg(hw, (u16)offset, dev_addr,
+					     data);
+	}
+
+	return ret_val;
+}