Re: [PATCH v4 1/4] can: m_can: Create a m_can platform framework

[Wolfgang Grandegger]

Hello Dan,

Am 22.01.19 um 14:04 schrieb Dan Murphy:
> Wolfgang
> 
> Thanks for the review
> 
> On 1/22/19 2:16 AM, Wolfgang Grandegger wrote:
>> Hello Dan,
>>
>> looks already quite good...
>>
>> Am 17.01.19 um 21:05 schrieb Dan Murphy:
>>> Create a m_can platform framework that peripherial
>>> devices can register to and use common code and register sets.
>>> The peripherial devices may provide read/write and configuration
>>> support of the IP.
>>>
>>> Signed-off-by: Dan Murphy <dmurphy@xxxxxx>
>>> ---
>>>  drivers/net/can/m_can/m_can.c          |   6 +
>>>  drivers/net/can/m_can/m_can_platform.c | 209 +++++++++++++++++++++++++
>>>  drivers/net/can/m_can/m_can_platform.h | 163 +++++++++++++++++++
>>>  3 files changed, 378 insertions(+)
>>>  create mode 100644 drivers/net/can/m_can/m_can_platform.c
>>>  create mode 100644 drivers/net/can/m_can/m_can_platform.h
>>>
>>> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
>>> index 9b449400376b..f817b28582e9 100644
>>> --- a/drivers/net/can/m_can/m_can.c
>>> +++ b/drivers/net/can/m_can/m_can.c
>>> @@ -414,6 +414,9 @@ static inline void m_can_config_endisable(const struct m_can_priv *priv,
>>>  	u32 timeout = 10;
>>>  	u32 val = 0;
>>>  
>>> +	if (cccr & CCCR_CSR)
>>> +		cccr &= ~CCCR_CSR;
>>> +
>>
>> This is an unrelated change/fix. Should go somewhere else.
>>
> 
> I thought I pulled this and the change below out of of this patchset.
> 
>>>  	if (enable) {
>>>  		/* enable m_can configuration */
>>>  		m_can_write(priv, M_CAN_CCCR, cccr | CCCR_INIT);
>>> @@ -1155,6 +1158,9 @@ static void m_can_chip_config(struct net_device *dev)
>>>  	m_can_set_bittiming(dev);
>>>  
>>>  	m_can_config_endisable(priv, false);
>>> +
>>> +	if (priv->device_init)
>>> +		priv->device_init(priv);
>>>  }
>>>  
>>>  static void m_can_start(struct net_device *dev)
>>> diff --git a/drivers/net/can/m_can/m_can_platform.c b/drivers/net/can/m_can/m_can_platform.c
>>> new file mode 100644
>>> index 000000000000..03172911323a
>>> --- /dev/null
>>> +++ b/drivers/net/can/m_can/m_can_platform.c
>>> @@ -0,0 +1,209 @@
>>> +/*
>>> + * CAN bus driver for Bosch M_CAN controller
>>> + *
>>> + * Copyright (C) 2014 Freescale Semiconductor, Inc.
>>> + *	Dong Aisheng <b29396@xxxxxxxxxxxxx>
>>> + *
>>> + * Bosch M_CAN user manual can be obtained from:
>>> + * http://www.bosch-semiconductors.de/media/pdf_1/ipmodules_1/m_can/
>>> + * mcan_users_manual_v302.pdf
>>> + *
>>> + * This file is licensed under the terms of the GNU General Public
>>> + * License version 2. This program is licensed "as is" without any
>>> + * warranty of any kind, whether express or implied.
>>> + */
>>> +
>>> +#include <linux/clk.h>
>>> +#include <linux/interrupt.h>
>>> +#include <linux/io.h>
>>> +#include <linux/kernel.h>
>>> +#include <linux/module.h>
>>> +#include <linux/netdevice.h>
>>> +#include <linux/platform_device.h>
>>> +#include <linux/pm_runtime.h>
>>> +#include <linux/can/dev.h>
>>> +#include <linux/pinctrl/consumer.h>
>>> +
>>> +#include "m_can_platform.h"
>>> +
>>> +struct m_can_plat_priv {
>>> +	void __iomem *base;
>>> +	void __iomem *mram_base;
>>> +};
>>> +
>>> +static u32 iomap_read_reg(struct m_can_classdev *m_can_class, int reg)
>>> +{
>>> +	struct m_can_plat_priv *priv = (struct m_can_plat_priv *)m_can_class->device_data;
>>> +
>>> +	return readl(priv->base + reg);
>>> +}
>>> +
>>> +static u32 iomap_read_fifo(struct m_can_classdev *m_can_class, int addr_offset)
>>
>> Why not just "offset".
>>
> 
> I can change the name
> 
>>> +{
>>> +	struct m_can_plat_priv *priv = (struct m_can_plat_priv *)m_can_class->device_data;
>>> +
>>> +	return readl(priv->mram_base + addr_offset);
>>> +}
>>> +
>>> +static int iomap_write_reg(struct m_can_classdev *m_can_class, int reg, int val)
>>> +{
>>> +	struct m_can_plat_priv *priv = (struct m_can_plat_priv *)m_can_class->device_data;
>>> +
>>> +	writel(val, priv->base + reg);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int iomap_write_fifo(struct m_can_classdev *m_can_class, int addr_offset, int val)
>>> +{
>>> +	struct m_can_plat_priv *priv = (struct m_can_plat_priv *)m_can_class->device_data;
>>> +
>>> +	writel(val, priv->base + addr_offset);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +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;
>>> +	int irq, ret = 0;
>>> +
>>> +	mcan_class = m_can_core_allocate_dev(&pdev->dev);
>>> +	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
>>> +	if (!priv)
>>> +		return -ENOMEM;
>>> +
>>> +	mcan_class->device_data = priv;
>>> +
>>> +	m_can_core_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->read_reg = &iomap_read_reg;
>>> +	mcan_class->write_reg = &iomap_write_reg;
>>> +	mcan_class->write_fifo = &iomap_write_fifo;
>>> +	mcan_class->read_fifo = &iomap_read_fifo;
>>
>> No "&" please!
>>
> 
> OK.  But can I ask why?

Well, to be honest, I cannot remember :(. I know that the convention in
the Linux kernel is without "&". Maybe somebody else can explain it!?

> 
>>> +	mcan_class->is_peripherial = false;
>>> +
>>> +	platform_set_drvdata(pdev, mcan_class->dev);
>>> +
>>> +	m_can_init_ram(mcan_class);
>>> +
>>> +	ret = m_can_core_register(mcan_class);
>>> +
>>> +failed_ret:
>>> +	return ret;
>>> +}
>>> +
>>> +static __maybe_unused int m_can_suspend(struct device *dev)
>>> +{
>>> +	return m_can_core_suspend(dev);
>>> +}
>>> +
>>> +static __maybe_unused int m_can_resume(struct device *dev)
>>> +{
>>> +	return m_can_core_resume(dev);
>>> +}
>>> +
>>> +static int m_can_plat_remove(struct platform_device *pdev)
>>> +{
>>> +	struct net_device *dev = platform_get_drvdata(pdev);
>>> +	struct m_can_classdev *mcan_class = netdev_priv(dev);
>>> +
>>> +	m_can_core_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_classdev *mcan_class = netdev_priv(ndev);
>>> +
>>> +	m_can_core_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_classdev *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_core_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@xxxxxxxxxxxxx>");
>>
>> Feel free to add yourself as second author.
>>
>>> +MODULE_LICENSE("GPL v2");
>>> +MODULE_DESCRIPTION("CAN bus driver for Bosch M_CAN controller");
>>> diff --git a/drivers/net/can/m_can/m_can_platform.h b/drivers/net/can/m_can/m_can_platform.h
>>> new file mode 100644
>>> index 000000000000..97e90dd79613
>>> --- /dev/null
>>> +++ b/drivers/net/can/m_can/m_can_platform.h
>>
>> These are common definitions, right? Therefore the filen name should be
>> "m_can.h"!?
>>
> 
> Ah yes.  My mistake common m_can definitions should be just m_can.
> 
>>> @@ -0,0 +1,163 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>> +// Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
>>> +
>>> +#ifndef _CAN_M_CAN_CORE_H_
>>> +#define _CAN_M_CAN_CORE_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>
>>
>> Do you really need them all in this header file?
>>
> 
> Probably not just a copy paste from the original m_can.  I will go through them and
> keep the common headers.
> 
>>> +
>>> +/* 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,
>>> +};
>>> +
>>> +/* registers definition */
>>> +enum m_can_reg {
>>> +	M_CAN_CREL	= 0x0,
>>> +	M_CAN_ENDN	= 0x4,
>>> +	M_CAN_CUST	= 0x8,
>>> +	M_CAN_DBTP	= 0xc,
>>> +	M_CAN_TEST	= 0x10,
>>> +	M_CAN_RWD	= 0x14,
>>> +	M_CAN_CCCR	= 0x18,
>>> +	M_CAN_NBTP	= 0x1c,
>>> +	M_CAN_TSCC	= 0x20,
>>> +	M_CAN_TSCV	= 0x24,
>>> +	M_CAN_TOCC	= 0x28,
>>> +	M_CAN_TOCV	= 0x2c,
>>> +	M_CAN_ECR	= 0x40,
>>> +	M_CAN_PSR	= 0x44,
>>> +/* TDCR Register only available for version >=3.1.x */
>>> +	M_CAN_TDCR	= 0x48,
>>> +	M_CAN_IR	= 0x50,
>>> +	M_CAN_IE	= 0x54,
>>> +	M_CAN_ILS	= 0x58,
>>> +	M_CAN_ILE	= 0x5c,
>>> +	M_CAN_GFC	= 0x80,
>>> +	M_CAN_SIDFC	= 0x84,
>>> +	M_CAN_XIDFC	= 0x88,
>>> +	M_CAN_XIDAM	= 0x90,
>>> +	M_CAN_HPMS	= 0x94,
>>> +	M_CAN_NDAT1	= 0x98,
>>> +	M_CAN_NDAT2	= 0x9c,
>>> +	M_CAN_RXF0C	= 0xa0,
>>> +	M_CAN_RXF0S	= 0xa4,
>>> +	M_CAN_RXF0A	= 0xa8,
>>> +	M_CAN_RXBC	= 0xac,
>>> +	M_CAN_RXF1C	= 0xb0,
>>> +	M_CAN_RXF1S	= 0xb4,
>>> +	M_CAN_RXF1A	= 0xb8,
>>> +	M_CAN_RXESC	= 0xbc,
>>> +	M_CAN_TXBC	= 0xc0,
>>> +	M_CAN_TXFQS	= 0xc4,
>>> +	M_CAN_TXESC	= 0xc8,
>>> +	M_CAN_TXBRP	= 0xcc,
>>> +	M_CAN_TXBAR	= 0xd0,
>>> +	M_CAN_TXBCR	= 0xd4,
>>> +	M_CAN_TXBTO	= 0xd8,
>>> +	M_CAN_TXBCF	= 0xdc,
>>> +	M_CAN_TXBTIE	= 0xe0,
>>> +	M_CAN_TXBCIE	= 0xe4,
>>> +	M_CAN_TXEFC	= 0xf0,
>>> +	M_CAN_TXEFS	= 0xf4,
>>> +	M_CAN_TXEFA	= 0xf8,
>>> +};
>>> +
>>> +/* address offset and element number for each FIFO/Buffer in the Message RAM */
>>> +struct mram_cfg {
>>> +	u16 off;
>>> +	u8  num;
>>> +};
>>> +
>>> +struct m_can_classdev;
>>> +
>>> +typedef	int (*can_dev_init) (struct m_can_classdev *m_can_class);
>>> +typedef	int (*can_clr_dev_interrupts) (struct m_can_classdev *m_can_class);
>>> +typedef	u32 (*can_reg_read) (struct m_can_classdev *m_can_class, int reg);
>>> +typedef	int (*can_reg_write) (struct m_can_classdev *m_can_class, int reg, int val);
>>> +typedef	u32 (*can_fifo_read) (struct m_can_classdev *m_can_class, int addr_offset);
>>> +typedef	int (*can_fifo_write) (struct m_can_classdev *m_can_class, int addr_offset, int val);
>>
>> No typedefs in the kernel, please!
>>
> 
> OK.  Just following some other conventions.  I can remove

See
https://elixir.bootlin.com/linux/latest/source/Documentation/process/coding-style.rst#L318

> 
>>> +struct m_can_classdev {
>>> +	struct can_priv can;
>>> +	struct napi_struct napi;
>>> +	struct net_device *net;
>>> +	struct device *dev;
>>> +	struct clk *hclk;
>>> +	struct clk *cclk;
>>> +
>>> +	struct workqueue_struct *wq;
>>> +	struct work_struct tx_work;
>>> +	struct sk_buff *skb;
>>> +
>>> +	struct can_bittiming_const *bit_timing;
>>> +	struct can_bittiming_const *data_timing;
>>> +
>>> +	void *device_data;
>>> +
>>> +	/* Device specific call backs */
>>> +	can_dev_init device_init;
>>> +	can_clr_dev_interrupts clr_dev_interrupts;
>>> +	can_reg_read read_reg;
>>> +	can_reg_write write_reg;
>>> +	can_fifo_read read_fifo;
>>> +	can_fifo_write write_fifo;
>>> +
>>> +	int version;
>>> +	int freq;
>>> +	u32 irqstatus;
>>> +
>>> +	int pm_clock_support;
>>> +	bool is_peripherial;
>>> +
>>> +	struct mram_cfg mcfg[MRAM_CFG_NUM];
>>> +};
>>> +
>>> +struct m_can_classdev *m_can_core_allocate_dev(struct device *dev);
>>> +int m_can_core_register(struct m_can_classdev *m_can_dev);
>>> +void m_can_core_unregister(struct m_can_classdev *m_can_dev);
>>> +int m_can_core_get_clocks(struct m_can_classdev *m_can_dev);
>>
>> You use here three different prefixes: "m_can_core", "m_can_classdev"
>> and "m_can_dev". There should be just one principle name for the struct,
>> func, args and vars, e.g.:
>>
>>   int m_can_device_register(struct m_can_device *mcan_dev);
>>
> 
> OK I will commonize the naming.  I may go with the above or call it m_can_class.

See also my related comment in the next patch.

Wolfgang.