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

Wolfgang Grandegger
2019-01-22T08:16:30Z

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.

> 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".

> +{
> + 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!

> + 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"!?

> @@ -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?

> +
> +/* 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!

> +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);

> +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