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/* Copyright (c) 2015-2016, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
/* Qualcomm Technologies, Inc. EMAC SGMII Controller driver.
*/
#include <linux/interrupt.h>
#include <linux/iopoll.h>
#include <linux/acpi.h>
#include <linux/of_device.h>
#include "emac.h"
#include "emac-mac.h"
#include "emac-sgmii.h"
/* EMAC_SGMII register offsets */
#define EMAC_SGMII_PHY_AUTONEG_CFG2 0x0048
#define EMAC_SGMII_PHY_SPEED_CFG1 0x0074
#define EMAC_SGMII_PHY_IRQ_CMD 0x00ac
#define EMAC_SGMII_PHY_INTERRUPT_CLEAR 0x00b0
#define EMAC_SGMII_PHY_INTERRUPT_MASK 0x00b4
#define EMAC_SGMII_PHY_INTERRUPT_STATUS 0x00b8
#define EMAC_SGMII_PHY_RX_CHK_STATUS 0x00d4
#define FORCE_AN_TX_CFG BIT(5)
#define FORCE_AN_RX_CFG BIT(4)
#define AN_ENABLE BIT(0)
#define DUPLEX_MODE BIT(4)
#define SPDMODE_1000 BIT(1)
#define SPDMODE_100 BIT(0)
#define SPDMODE_10 0
#define CDR_ALIGN_DET BIT(6)
#define IRQ_GLOBAL_CLEAR BIT(0)
#define DECODE_CODE_ERR BIT(7)
#define DECODE_DISP_ERR BIT(6)
#define SGMII_PHY_IRQ_CLR_WAIT_TIME 10
#define SGMII_PHY_INTERRUPT_ERR (DECODE_CODE_ERR | DECODE_DISP_ERR)
#define SGMII_ISR_MASK (SGMII_PHY_INTERRUPT_ERR)
#define SERDES_START_WAIT_TIMES 100
/* Initialize the SGMII link between the internal and external PHYs. */
static void emac_sgmii_link_init(struct emac_adapter *adpt)
{
struct emac_sgmii *phy = &adpt->phy;
u32 val;
/* Always use autonegotiation. It works no matter how the external
* PHY is configured.
*/
val = readl(phy->base + EMAC_SGMII_PHY_AUTONEG_CFG2);
val &= ~(FORCE_AN_RX_CFG | FORCE_AN_TX_CFG);
val |= AN_ENABLE;
writel(val, phy->base + EMAC_SGMII_PHY_AUTONEG_CFG2);
}
static int emac_sgmii_irq_clear(struct emac_adapter *adpt, u32 irq_bits)
{
struct emac_sgmii *phy = &adpt->phy;
u32 status;
writel_relaxed(irq_bits, phy->base + EMAC_SGMII_PHY_INTERRUPT_CLEAR);
writel_relaxed(IRQ_GLOBAL_CLEAR, phy->base + EMAC_SGMII_PHY_IRQ_CMD);
/* Ensure interrupt clear command is written to HW */
wmb();
/* After set the IRQ_GLOBAL_CLEAR bit, the status clearing must
* be confirmed before clearing the bits in other registers.
* It takes a few cycles for hw to clear the interrupt status.
*/
if (readl_poll_timeout_atomic(phy->base +
EMAC_SGMII_PHY_INTERRUPT_STATUS,
status, !(status & irq_bits), 1,
SGMII_PHY_IRQ_CLR_WAIT_TIME)) {
netdev_err(adpt->netdev,
"error: failed clear SGMII irq: status:0x%x bits:0x%x\n",
status, irq_bits);
return -EIO;
}
/* Finalize clearing procedure */
writel_relaxed(0, phy->base + EMAC_SGMII_PHY_IRQ_CMD);
writel_relaxed(0, phy->base + EMAC_SGMII_PHY_INTERRUPT_CLEAR);
/* Ensure that clearing procedure finalization is written to HW */
wmb();
return 0;
}
/* The number of decode errors that triggers a reset */
#define DECODE_ERROR_LIMIT 2
static irqreturn_t emac_sgmii_interrupt(int irq, void *data)
{
struct emac_adapter *adpt = data;
struct emac_sgmii *phy = &adpt->phy;
u32 status;
status = readl(phy->base + EMAC_SGMII_PHY_INTERRUPT_STATUS);
status &= SGMII_ISR_MASK;
if (!status)
return IRQ_HANDLED;
/* If we get a decoding error and CDR is not locked, then try
* resetting the internal PHY. The internal PHY uses an embedded
* clock with Clock and Data Recovery (CDR) to recover the
* clock and data.
*/
if (status & SGMII_PHY_INTERRUPT_ERR) {
int count;
/* The SGMII is capable of recovering from some decode
* errors automatically. However, if we get multiple
* decode errors in a row, then assume that something
* is wrong and reset the interface.
*/
count = atomic_inc_return(&phy->decode_error_count);
if (count == DECODE_ERROR_LIMIT) {
schedule_work(&adpt->work_thread);
atomic_set(&phy->decode_error_count, 0);
}
} else {
/* We only care about consecutive decode errors. */
atomic_set(&phy->decode_error_count, 0);
}
if (emac_sgmii_irq_clear(adpt, status)) {
netdev_warn(adpt->netdev, "failed to clear SGMII interrupt\n");
schedule_work(&adpt->work_thread);
}
return IRQ_HANDLED;
}
static void emac_sgmii_reset_prepare(struct emac_adapter *adpt)
{
struct emac_sgmii *phy = &adpt->phy;
u32 val;
/* Reset PHY */
val = readl(phy->base + EMAC_EMAC_WRAPPER_CSR2);
writel(((val & ~PHY_RESET) | PHY_RESET), phy->base +
EMAC_EMAC_WRAPPER_CSR2);
/* Ensure phy-reset command is written to HW before the release cmd */
msleep(50);
val = readl(phy->base + EMAC_EMAC_WRAPPER_CSR2);
writel((val & ~PHY_RESET), phy->base + EMAC_EMAC_WRAPPER_CSR2);
/* Ensure phy-reset release command is written to HW before initializing
* SGMII
*/
msleep(50);
}
void emac_sgmii_reset(struct emac_adapter *adpt)
{
int ret;
emac_sgmii_reset_prepare(adpt);
emac_sgmii_link_init(adpt);
ret = adpt->phy.initialize(adpt);
if (ret)
netdev_err(adpt->netdev,
"could not reinitialize internal PHY (error=%i)\n",
ret);
}
static int emac_sgmii_open(struct emac_adapter *adpt)
{
struct emac_sgmii *sgmii = &adpt->phy;
int ret;
if (sgmii->irq) {
/* Make sure interrupts are cleared and disabled first */
ret = emac_sgmii_irq_clear(adpt, 0xff);
if (ret)
return ret;
writel(0, sgmii->base + EMAC_SGMII_PHY_INTERRUPT_MASK);
ret = request_irq(sgmii->irq, emac_sgmii_interrupt, 0,
"emac-sgmii", adpt);
if (ret) {
netdev_err(adpt->netdev,
"could not register handler for internal PHY\n");
return ret;
}
}
return 0;
}
static int emac_sgmii_close(struct emac_adapter *adpt)
{
struct emac_sgmii *sgmii = &adpt->phy;
/* Make sure interrupts are disabled */
writel(0, sgmii->base + EMAC_SGMII_PHY_INTERRUPT_MASK);
free_irq(sgmii->irq, adpt);
return 0;
}
/* The error interrupts are only valid after the link is up */
static int emac_sgmii_link_up(struct emac_adapter *adpt)
{
struct emac_sgmii *sgmii = &adpt->phy;
int ret;
/* Clear and enable interrupts */
ret = emac_sgmii_irq_clear(adpt, 0xff);
if (ret)
return ret;
writel(SGMII_ISR_MASK, sgmii->base + EMAC_SGMII_PHY_INTERRUPT_MASK);
return 0;
}
static int emac_sgmii_link_down(struct emac_adapter *adpt)
{
struct emac_sgmii *sgmii = &adpt->phy;
/* Disable interrupts */
writel(0, sgmii->base + EMAC_SGMII_PHY_INTERRUPT_MASK);
synchronize_irq(sgmii->irq);
return 0;
}
static int emac_sgmii_acpi_match(struct device *dev, void *data)
{
#ifdef CONFIG_ACPI
static const struct acpi_device_id match_table[] = {
{
.id = "QCOM8071",
},
{}
};
const struct acpi_device_id *id = acpi_match_device(match_table, dev);
emac_sgmii_function *initialize = data;
if (id) {
acpi_handle handle = ACPI_HANDLE(dev);
unsigned long long hrv;
acpi_status status;
status = acpi_evaluate_integer(handle, "_HRV", NULL, &hrv);
if (status) {
if (status == AE_NOT_FOUND)
/* Older versions of the QDF2432 ACPI tables do
* not have an _HRV property.
*/
hrv = 1;
else
/* Something is wrong with the tables */
return 0;
}
switch (hrv) {
case 1:
*initialize = emac_sgmii_init_qdf2432;
return 1;
case 2:
*initialize = emac_sgmii_init_qdf2400;
return 1;
}
}
#endif
return 0;
}
static const struct of_device_id emac_sgmii_dt_match[] = {
{
.compatible = "qcom,fsm9900-emac-sgmii",
.data = emac_sgmii_init_fsm9900,
},
{
.compatible = "qcom,qdf2432-emac-sgmii",
.data = emac_sgmii_init_qdf2432,
},
{}
};
/* Dummy function for systems without an internal PHY. This avoids having
* to check for NULL pointers before calling the functions.
*/
static int emac_sgmii_dummy(struct emac_adapter *adpt)
{
return 0;
}
int emac_sgmii_config(struct platform_device *pdev, struct emac_adapter *adpt)
{
struct platform_device *sgmii_pdev = NULL;
struct emac_sgmii *phy = &adpt->phy;
struct resource *res;
int ret;
if (has_acpi_companion(&pdev->dev)) {
struct device *dev;
dev = device_find_child(&pdev->dev, &phy->initialize,
emac_sgmii_acpi_match);
if (!dev) {
dev_warn(&pdev->dev, "cannot find internal phy node\n");
/* There is typically no internal PHY on emulation
* systems, so if we can't find the node, assume
* we are on an emulation system and stub-out
* support for the internal PHY. These systems only
* use ACPI.
*/
phy->open = emac_sgmii_dummy;
phy->close = emac_sgmii_dummy;
phy->link_up = emac_sgmii_dummy;
phy->link_down = emac_sgmii_dummy;
return 0;
}
sgmii_pdev = to_platform_device(dev);
} else {
const struct of_device_id *match;
struct device_node *np;
np = of_parse_phandle(pdev->dev.of_node, "internal-phy", 0);
if (!np) {
dev_err(&pdev->dev, "missing internal-phy property\n");
return -ENODEV;
}
sgmii_pdev = of_find_device_by_node(np);
if (!sgmii_pdev) {
dev_err(&pdev->dev, "invalid internal-phy property\n");
return -ENODEV;
}
match = of_match_device(emac_sgmii_dt_match, &sgmii_pdev->dev);
if (!match) {
dev_err(&pdev->dev, "unrecognized internal phy node\n");
ret = -ENODEV;
goto error_put_device;
}
phy->initialize = (emac_sgmii_function)match->data;
}
phy->open = emac_sgmii_open;
phy->close = emac_sgmii_close;
phy->link_up = emac_sgmii_link_up;
phy->link_down = emac_sgmii_link_down;
/* Base address is the first address */
res = platform_get_resource(sgmii_pdev, IORESOURCE_MEM, 0);
if (!res) {
ret = -EINVAL;
goto error_put_device;
}
phy->base = ioremap(res->start, resource_size(res));
if (!phy->base) {
ret = -ENOMEM;
goto error_put_device;
}
/* v2 SGMII has a per-lane digital digital, so parse it if it exists */
res = platform_get_resource(sgmii_pdev, IORESOURCE_MEM, 1);
if (res) {
phy->digital = ioremap(res->start, resource_size(res));
if (!phy->digital) {
ret = -ENOMEM;
goto error_unmap_base;
}
}
ret = phy->initialize(adpt);
if (ret)
goto error;
emac_sgmii_link_init(adpt);
ret = platform_get_irq(sgmii_pdev, 0);
if (ret > 0)
phy->irq = ret;
/* We've remapped the addresses, so we don't need the device any
* more. of_find_device_by_node() says we should release it.
*/
put_device(&sgmii_pdev->dev);
return 0;
error:
if (phy->digital)
iounmap(phy->digital);
error_unmap_base:
iounmap(phy->base);
error_put_device:
put_device(&sgmii_pdev->dev);
return ret;
}