can: m_can: Create a m_can platform framework

Create a m_can platform framework that peripheral
devices can register to and use common code and register sets.
The peripheral devices may provide read/write and configuration
support of the IP.
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Dan Murphy <dmurphy@ti.com>
Acked-by: Faiz Abbas <faiz_abbas@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/m_can/Kconfig

 # SPDX-License-Identifier: GPL-2.0-only
 config CAN_M_CAN
+	tristate "Bosch M_CAN support"
+	---help---
+	  Say Y here if you want support for Bosch M_CAN controller framework.
+	  This is common support for devices that embed the Bosch M_CAN IP.
+
+config CAN_M_CAN_PLATFORM
+	tristate "Bosch M_CAN support for io-mapped devices"
 	depends on HAS_IOMEM
-	tristate "Bosch M_CAN devices"
+	depends on CAN_M_CAN
 	---help---
-	  Say Y here if you want to support for Bosch M_CAN controller.
+	  Say Y here if you want support for IO Mapped Bosch M_CAN controller.
+	  This support is for devices that have the Bosch M_CAN controller
+	  IP embedded into the device and the IP is IO Mapped to the processor.

drivers/net/can/m_can/Makefile

@@ -4,3 +4,4 @@
 #
 
 obj-$(CONFIG_CAN_M_CAN) += m_can.o
+obj-$(CONFIG_CAN_M_CAN_PLATFORM) += m_can_platform.o

drivers/net/can/m_can/m_can.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/* CAN bus driver for Bosch M_CAN controller
+ * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+ */
+
+#ifndef _CAN_M_CAN_H_
+#define _CAN_M_CAN_H_
+
+#include <linux/can/core.h>
+#include <linux/can/led.h>
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/freezer.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/iopoll.h>
+#include <linux/can/dev.h>
+#include <linux/pinctrl/consumer.h>
+
+/* m_can lec values */
+enum m_can_lec_type {
+	LEC_NO_ERROR = 0,
+	LEC_STUFF_ERROR,
+	LEC_FORM_ERROR,
+	LEC_ACK_ERROR,
+	LEC_BIT1_ERROR,
+	LEC_BIT0_ERROR,
+	LEC_CRC_ERROR,
+	LEC_UNUSED,
+};
+
+enum m_can_mram_cfg {
+	MRAM_SIDF = 0,
+	MRAM_XIDF,
+	MRAM_RXF0,
+	MRAM_RXF1,
+	MRAM_RXB,
+	MRAM_TXE,
+	MRAM_TXB,
+	MRAM_CFG_NUM,
+};
+
+/* address offset and element number for each FIFO/Buffer in the Message RAM */
+struct mram_cfg {
+	u16 off;
+	u8  num;
+};
+
+struct m_can_priv;
+struct m_can_ops {
+	/* Device specific call backs */
+	int (*clear_interrupts)(struct m_can_priv *m_can_class);
+	u32 (*read_reg)(struct m_can_priv *m_can_class, int reg);
+	int (*write_reg)(struct m_can_priv *m_can_class, int reg, int val);
+	u32 (*read_fifo)(struct m_can_priv *m_can_class, int addr_offset);
+	int (*write_fifo)(struct m_can_priv *m_can_class, int addr_offset,
+			  int val);
+	int (*init)(struct m_can_priv *m_can_class);
+};
+
+struct m_can_priv {
+	struct can_priv can;
+	struct napi_struct napi;
+	struct net_device *net;
+	struct device *dev;
+	struct clk *hclk;
+	struct clk *cclk;
+
+	struct workqueue_struct *tx_wq;
+	struct work_struct tx_work;
+	struct sk_buff *tx_skb;
+
+	struct can_bittiming_const *bit_timing;
+	struct can_bittiming_const *data_timing;
+
+	struct m_can_ops *ops;
+
+	void *device_data;
+
+	int version;
+	int freq;
+	u32 irqstatus;
+
+	int pm_clock_support;
+	int is_peripheral;
+
+	struct mram_cfg mcfg[MRAM_CFG_NUM];
+};
+
+struct m_can_priv *m_can_class_allocate_dev(struct device *dev);
+int m_can_class_register(struct m_can_priv *m_can_dev);
+void m_can_class_unregister(struct m_can_priv *m_can_dev);
+int m_can_class_get_clocks(struct m_can_priv *m_can_dev);
+void m_can_init_ram(struct m_can_priv *priv);
+void m_can_config_endisable(struct m_can_priv *priv, bool enable);
+
+int m_can_class_suspend(struct device *dev);
+int m_can_class_resume(struct device *dev);
+#endif	/* _CAN_M_H_ */

drivers/net/can/m_can/m_can_platform.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/platform_device.h>
+
+#include "m_can.h"
+
+struct m_can_plat_priv {
+	void __iomem *base;
+	void __iomem *mram_base;
+};
+
+static u32 iomap_read_reg(struct m_can_priv *cdev, int reg)
+{
+	struct m_can_plat_priv *priv =
+			(struct m_can_plat_priv *)cdev->device_data;
+
+	return readl(priv->base + reg);
+}
+
+static u32 iomap_read_fifo(struct m_can_priv *cdev, int offset)
+{
+	struct m_can_plat_priv *priv =
+			(struct m_can_plat_priv *)cdev->device_data;
+
+	return readl(priv->mram_base + offset);
+}
+
+static int iomap_write_reg(struct m_can_priv *cdev, int reg, int val)
+{
+	struct m_can_plat_priv *priv =
+			(struct m_can_plat_priv *)cdev->device_data;
+
+	writel(val, priv->base + reg);
+
+	return 0;
+}
+
+static int iomap_write_fifo(struct m_can_priv *cdev, int offset, int val)
+{
+	struct m_can_plat_priv *priv =
+			(struct m_can_plat_priv *)cdev->device_data;
+
+	writel(val, priv->mram_base + offset);
+
+	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_priv *mcan_class;
+	struct m_can_plat_priv *priv;
+	struct resource *res;
+	void __iomem *addr;
+	void __iomem *mram_addr;
+	int irq, ret = 0;
+
+	mcan_class = m_can_class_allocate_dev(&pdev->dev);
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	mcan_class->device_data = priv;
+
+	m_can_class_get_clocks(mcan_class);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "m_can");
+	addr = devm_ioremap_resource(&pdev->dev, res);
+	irq = platform_get_irq_byname(pdev, "int0");
+	if (IS_ERR(addr) || irq < 0) {
+		ret = -EINVAL;
+		goto failed_ret;
+	}
+
+	/* message ram could be shared */
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram");
+	if (!res) {
+		ret = -ENODEV;
+		goto failed_ret;
+	}
+
+	mram_addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
+	if (!mram_addr) {
+		ret = -ENOMEM;
+		goto failed_ret;
+	}
+
+	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->ops = &m_can_plat_ops;
+
+	mcan_class->is_peripheral = false;
+
+	platform_set_drvdata(pdev, mcan_class->dev);
+
+	m_can_init_ram(mcan_class);
+
+	ret = m_can_class_register(mcan_class);
+
+failed_ret:
+	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 int m_can_plat_remove(struct platform_device *pdev)
+{
+	struct net_device *dev = platform_get_drvdata(pdev);
+	struct m_can_priv *mcan_class = netdev_priv(dev);
+
+	m_can_class_unregister(mcan_class);
+
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static int __maybe_unused m_can_runtime_suspend(struct device *dev)
+{
+	struct net_device *ndev = dev_get_drvdata(dev);
+	struct m_can_priv *mcan_class = netdev_priv(ndev);
+
+	m_can_class_suspend(dev);
+
+	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 net_device *ndev = dev_get_drvdata(dev);
+	struct m_can_priv *mcan_class = netdev_priv(ndev);
+	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);
+
+	m_can_class_resume(dev);
+
+	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 = 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");