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

Dan Murphy
2019-01-22T13:04:01Z

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@ti.com>
>> ---
>> 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@freescale.com>
>> + *
>> + * 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?

>> + 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@freescale.com>");
>
> 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

>> +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.

Dan

>> +void m_can_init_ram(struct m_can_classdev *priv);
>> +void m_can_config_endisable(const struct m_can_classdev *priv, bool enable);
>> +
>> +int m_can_core_suspend(struct device *dev);
>> +int m_can_core_resume(struct device *dev);
>> +#endif /* _CAN_M_CAN_CORE_H_ */
>>
>
> Wolfgang
>

--
------------------
Dan Murphy