linux-stable/drivers/net/can/m_can/m_can_platform.c
Judith Mendez b382380c0d can: m_can: Add hrtimer to generate software interrupt
Introduce timer polling method to MCAN since some SoCs may not
have M_CAN interrupt routed to A53 Linux and do not have
interrupt property in device tree M_CAN node.

On AM62x SoC, MCANs on MCU domain do not have hardware interrupt
routed to A53 Linux, instead they will use timer polling method.

Add an hrtimer to MCAN class device. Each MCAN will have its own
hrtimer instantiated if there is no hardware interrupt found in
device tree M_CAN node. The timer will generate a software
interrupt every 1 ms. In hrtimer callback, we check if there is
a transaction pending by reading a register, then process by
calling the isr if there is.

Tested-by: Hiago De Franco <hiago.franco@toradex.com> # Toradex Verdin AM62
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Judith Mendez <jm@ti.com>
Link: https://lore.kernel.org/all/20230707204714.62964-3-jm@ti.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2023-07-17 16:02:24 +02:00

245 lines
5.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
// IOMapped CAN bus driver for Bosch M_CAN controller
// Copyright (C) 2014 Freescale Semiconductor, Inc.
// Dong Aisheng <b29396@freescale.com>
//
// Copyright (C) 2018-19 Texas Instruments Incorporated - http://www.ti.com/
#include <linux/hrtimer.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include "m_can.h"
struct m_can_plat_priv {
struct m_can_classdev cdev;
void __iomem *base;
void __iomem *mram_base;
};
static inline struct m_can_plat_priv *cdev_to_priv(struct m_can_classdev *cdev)
{
return container_of(cdev, struct m_can_plat_priv, cdev);
}
static u32 iomap_read_reg(struct m_can_classdev *cdev, int reg)
{
struct m_can_plat_priv *priv = cdev_to_priv(cdev);
return readl(priv->base + reg);
}
static int iomap_read_fifo(struct m_can_classdev *cdev, int offset, void *val, size_t val_count)
{
struct m_can_plat_priv *priv = cdev_to_priv(cdev);
void __iomem *src = priv->mram_base + offset;
while (val_count--) {
*(unsigned int *)val = ioread32(src);
val += 4;
src += 4;
}
return 0;
}
static int iomap_write_reg(struct m_can_classdev *cdev, int reg, int val)
{
struct m_can_plat_priv *priv = cdev_to_priv(cdev);
writel(val, priv->base + reg);
return 0;
}
static int iomap_write_fifo(struct m_can_classdev *cdev, int offset,
const void *val, size_t val_count)
{
struct m_can_plat_priv *priv = cdev_to_priv(cdev);
void __iomem *dst = priv->mram_base + offset;
while (val_count--) {
iowrite32(*(unsigned int *)val, dst);
val += 4;
dst += 4;
}
return 0;
}
static struct m_can_ops m_can_plat_ops = {
.read_reg = iomap_read_reg,
.write_reg = iomap_write_reg,
.write_fifo = iomap_write_fifo,
.read_fifo = iomap_read_fifo,
};
static int m_can_plat_probe(struct platform_device *pdev)
{
struct m_can_classdev *mcan_class;
struct m_can_plat_priv *priv;
struct resource *res;
void __iomem *addr;
void __iomem *mram_addr;
struct phy *transceiver;
int irq = 0, ret = 0;
mcan_class = m_can_class_allocate_dev(&pdev->dev,
sizeof(struct m_can_plat_priv));
if (!mcan_class)
return -ENOMEM;
priv = cdev_to_priv(mcan_class);
ret = m_can_class_get_clocks(mcan_class);
if (ret)
goto probe_fail;
addr = devm_platform_ioremap_resource_byname(pdev, "m_can");
if (IS_ERR(addr)) {
ret = PTR_ERR(addr);
goto probe_fail;
}
if (device_property_present(mcan_class->dev, "interrupts") ||
device_property_present(mcan_class->dev, "interrupt-names")) {
irq = platform_get_irq_byname(pdev, "int0");
if (irq < 0) {
ret = irq;
goto probe_fail;
}
} else {
dev_dbg(mcan_class->dev, "Polling enabled, initialize hrtimer");
hrtimer_init(&mcan_class->hrtimer, CLOCK_MONOTONIC,
HRTIMER_MODE_REL_PINNED);
}
/* message ram could be shared */
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram");
if (!res) {
ret = -ENODEV;
goto probe_fail;
}
mram_addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
if (!mram_addr) {
ret = -ENOMEM;
goto probe_fail;
}
transceiver = devm_phy_optional_get(&pdev->dev, NULL);
if (IS_ERR(transceiver)) {
ret = PTR_ERR(transceiver);
dev_err_probe(&pdev->dev, ret, "failed to get phy\n");
goto probe_fail;
}
if (transceiver)
mcan_class->can.bitrate_max = transceiver->attrs.max_link_rate;
priv->base = addr;
priv->mram_base = mram_addr;
mcan_class->net->irq = irq;
mcan_class->pm_clock_support = 1;
mcan_class->can.clock.freq = clk_get_rate(mcan_class->cclk);
mcan_class->dev = &pdev->dev;
mcan_class->transceiver = transceiver;
mcan_class->ops = &m_can_plat_ops;
mcan_class->is_peripheral = false;
platform_set_drvdata(pdev, mcan_class);
pm_runtime_enable(mcan_class->dev);
ret = m_can_class_register(mcan_class);
if (ret)
goto out_runtime_disable;
return ret;
out_runtime_disable:
pm_runtime_disable(mcan_class->dev);
probe_fail:
m_can_class_free_dev(mcan_class->net);
return ret;
}
static __maybe_unused int m_can_suspend(struct device *dev)
{
return m_can_class_suspend(dev);
}
static __maybe_unused int m_can_resume(struct device *dev)
{
return m_can_class_resume(dev);
}
static void m_can_plat_remove(struct platform_device *pdev)
{
struct m_can_plat_priv *priv = platform_get_drvdata(pdev);
struct m_can_classdev *mcan_class = &priv->cdev;
m_can_class_unregister(mcan_class);
m_can_class_free_dev(mcan_class->net);
}
static int __maybe_unused m_can_runtime_suspend(struct device *dev)
{
struct m_can_plat_priv *priv = dev_get_drvdata(dev);
struct m_can_classdev *mcan_class = &priv->cdev;
clk_disable_unprepare(mcan_class->cclk);
clk_disable_unprepare(mcan_class->hclk);
return 0;
}
static int __maybe_unused m_can_runtime_resume(struct device *dev)
{
struct m_can_plat_priv *priv = dev_get_drvdata(dev);
struct m_can_classdev *mcan_class = &priv->cdev;
int err;
err = clk_prepare_enable(mcan_class->hclk);
if (err)
return err;
err = clk_prepare_enable(mcan_class->cclk);
if (err)
clk_disable_unprepare(mcan_class->hclk);
return err;
}
static const struct dev_pm_ops m_can_pmops = {
SET_RUNTIME_PM_OPS(m_can_runtime_suspend,
m_can_runtime_resume, NULL)
SET_SYSTEM_SLEEP_PM_OPS(m_can_suspend, m_can_resume)
};
static const struct of_device_id m_can_of_table[] = {
{ .compatible = "bosch,m_can", .data = NULL },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, m_can_of_table);
static struct platform_driver m_can_plat_driver = {
.driver = {
.name = KBUILD_MODNAME,
.of_match_table = m_can_of_table,
.pm = &m_can_pmops,
},
.probe = m_can_plat_probe,
.remove_new = m_can_plat_remove,
};
module_platform_driver(m_can_plat_driver);
MODULE_AUTHOR("Dong Aisheng <b29396@freescale.com>");
MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("M_CAN driver for IO Mapped Bosch controllers");