On 07/11/2014 05:33 PM, Marc Kleine-Budde wrote:
On 07/11/2014 01:13 PM, Varka Bhadram wrote:
On 07/11/2014 03:59 PM, Dong Aisheng wrote:
(...)
+/* m_can private data structure */
+struct m_can_priv {
+ struct can_priv can; /* must be the first member */
+ struct napi_struct napi;
+ struct net_device *dev;
+ struct device *device;
+ struct clk *hclk;
+ struct clk *cclk;
+ void __iomem *base;
+ u32 irqstatus;
+
+ /* message ram configuration */
+ void __iomem *mram_base;
+ struct mram_cfg mcfg[MRAM_CFG_NUM];
+};
+
It will be good if we write the comments for the driver private structure
+static inline u32 m_can_read(const struct m_can_priv *priv, enum
m_can_reg reg)
+{
+ return readl(priv->base + reg);
+}
+
(...)
+static void free_m_can_dev(struct net_device *dev)
+{
+ free_candev(dev);
+}
+
Why do we need a separate function which calls a single function... :-)
To be symetric with alloc_m_can_dev()
+static struct net_device *alloc_m_can_dev(void)
+{
+ struct net_device *dev;
+ struct m_can_priv *priv;
+
+ dev = alloc_candev(sizeof(struct m_can_priv), 1);
sizeof(*priv)...?
+ if (!dev)
+ return NULL;
Return value -ENOMEM ?
I'm okay with NULL, however if we want to return an arror value, it must
be ERR_PTR() wrapped.
+
+ priv = netdev_priv(dev);
+ netif_napi_add(dev, &priv->napi, m_can_poll, M_CAN_NAPI_WEIGHT);
+
+ priv->dev = dev;
+ priv->can.bittiming_const = &m_can_bittiming_const;
+ priv->can.do_set_mode = m_can_set_mode;
+ priv->can.do_get_berr_counter = m_can_get_berr_counter;
+ priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
+ CAN_CTRLMODE_LISTENONLY |
+ CAN_CTRLMODE_BERR_REPORTING;
+
+ return dev;
+}
+
+static int m_can_open(struct net_device *dev)
+{
+ struct m_can_priv *priv = netdev_priv(dev);
+ int err;
+
+ err = clk_prepare_enable(priv->hclk);
+ if (err)
+ return err;
+
+ err = clk_prepare_enable(priv->cclk);
+ if (err)
+ goto exit_disable_hclk;
+
+ /* open the can device */
+ err = open_candev(dev);
+ if (err) {
+ netdev_err(dev, "failed to open can device\n");
+ goto exit_disable_cclk;
+ }
+
+ /* register interrupt handler */
+ err = request_irq(dev->irq, m_can_isr, IRQF_SHARED, dev->name,
+ dev);
why don't we use devm_request_irq()...? If you use this no need to worry
about freeing the irq
...because the IRQ is allocated during ifup and released during ifdown.
+ if (err < 0) {
+ netdev_err(dev, "failed to request interrupt\n");
+ goto exit_irq_fail;
+ }
+
+ /* start the m_can controller */
+ m_can_start(dev);
+
+ can_led_event(dev, CAN_LED_EVENT_OPEN);
+ napi_enable(&priv->napi);
+ netif_start_queue(dev);
+
+ return 0;
+
+exit_irq_fail:
+ close_candev(dev);
+exit_disable_cclk:
+ clk_disable_unprepare(priv->cclk);
+exit_disable_hclk:
+ clk_disable_unprepare(priv->hclk);
+ return err;
+}
+
+static void m_can_stop(struct net_device *dev)
+{
+ struct m_can_priv *priv = netdev_priv(dev);
+
+ /* disable all interrupts */
+ m_can_disable_all_interrupts(priv);
+
+ clk_disable_unprepare(priv->hclk);
+ clk_disable_unprepare(priv->cclk);
+
+ /* set the state as STOPPED */
+ priv->can.state = CAN_STATE_STOPPED;
+}
+
+static int m_can_close(struct net_device *dev)
+{
+ struct m_can_priv *priv = netdev_priv(dev);
+
+ netif_stop_queue(dev);
+ napi_disable(&priv->napi);
+ m_can_stop(dev);
+ free_irq(dev->irq, dev);
not required when you use devm_request_irq()
No....see above.
+ close_candev(dev);
+ can_led_event(dev, CAN_LED_EVENT_STOP);
+
+ return 0;
+}
+
(...)
+
+static const struct of_device_id m_can_of_table[] = {
+ { .compatible = "bosch,m_can", .data = NULL },
we can simply give '0' . No need of .data = NULL. Things should be
simple right.... :-)
.data should be a pointer, while "0" isn't. (Although 0 is valid C, we
don't want a integer 0 to initialize a pointer.) However, you can omit
.data = NULL completely. When initialzing via C99, any omited members of
the struct will automatically be initialized with 0x0. I like to see the
.data = NULL because it documents that there isn't any data (yet), once
another compatible is added, we need the .data anyways.
static const struct of_device_id m_can_of_table[] = {
{ .compatible = "bosch,m_can", },
};
This is enough... right ?
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, m_can_of_table);
+
+static int m_can_of_parse_mram(struct platform_device *pdev,
+ struct m_can_priv *priv)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct resource *res;
+ void __iomem *addr;
+ u32 out_val[MRAM_CFG_LEN];
+ int ret;
+
+ /* message ram could be shared */
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
"message_ram");
+ if (!res)
+ return -ENODEV;
+
+ addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
+ if (!addr)
+ return -ENODEV;
Is this err return is appropriate ... ?
-ENOMEM seems to be more commonly used.
+
+ /* get message ram configuration */
+ ret = of_property_read_u32_array(np, "mram-cfg",
+ out_val, sizeof(out_val) / 4);
+ if (ret) {
+ dev_err(&pdev->dev, "can not get message ram configuration\n");
+ return -ENODEV;
+ }
+
Is this err return is appropriate ... ?
Whay do you suggest?
+ priv->mram_base = addr;
+ priv->mcfg[MRAM_SIDF].off = out_val[0];
+ priv->mcfg[MRAM_SIDF].num = out_val[1];
+ priv->mcfg[MRAM_XIDF].off = priv->mcfg[MRAM_SIDF].off +
+ priv->mcfg[MRAM_SIDF].num * SIDF_ELEMENT_SIZE;
+ priv->mcfg[MRAM_XIDF].num = out_val[2];
+ priv->mcfg[MRAM_RXF0].off = priv->mcfg[MRAM_XIDF].off +
+ priv->mcfg[MRAM_XIDF].num * XIDF_ELEMENT_SIZE;
+ priv->mcfg[MRAM_RXF0].num = out_val[3] & RXFC_FS_MASK;
+ priv->mcfg[MRAM_RXF1].off = priv->mcfg[MRAM_RXF0].off +
+ priv->mcfg[MRAM_RXF0].num * RXF0_ELEMENT_SIZE;
+ priv->mcfg[MRAM_RXF1].num = out_val[4] & RXFC_FS_MASK;
+ priv->mcfg[MRAM_RXB].off = priv->mcfg[MRAM_RXF1].off +
+ priv->mcfg[MRAM_RXF1].num * RXF1_ELEMENT_SIZE;
+ priv->mcfg[MRAM_RXB].num = out_val[5];
+ priv->mcfg[MRAM_TXE].off = priv->mcfg[MRAM_RXB].off +
+ priv->mcfg[MRAM_RXB].num * RXB_ELEMENT_SIZE;
+ priv->mcfg[MRAM_TXE].num = out_val[6];
+ priv->mcfg[MRAM_TXB].off = priv->mcfg[MRAM_TXE].off +
+ priv->mcfg[MRAM_TXE].num * TXE_ELEMENT_SIZE;
+ priv->mcfg[MRAM_TXB].num = out_val[7] & TXBC_NDTB_MASK;
+
+ dev_dbg(&pdev->dev, "mram_base %p sidf 0x%x %d xidf 0x%x %d rxf0
0x%x %d rxf1 0x%x %d rxb 0x%x %d txe 0x%x %d txb 0x%x %d\n",
+ priv->mram_base,
+ priv->mcfg[MRAM_SIDF].off, priv->mcfg[MRAM_SIDF].num,
+ priv->mcfg[MRAM_XIDF].off, priv->mcfg[MRAM_XIDF].num,
+ priv->mcfg[MRAM_RXF0].off, priv->mcfg[MRAM_RXF0].num,
+ priv->mcfg[MRAM_RXF1].off, priv->mcfg[MRAM_RXF1].num,
+ priv->mcfg[MRAM_RXB].off, priv->mcfg[MRAM_RXB].num,
+ priv->mcfg[MRAM_TXE].off, priv->mcfg[MRAM_TXE].num,
+ priv->mcfg[MRAM_TXB].off, priv->mcfg[MRAM_TXB].num);
+
dev_dbg() will insert the new lines in b/w. It wont print the values as
you expected.
Check this by enabling debug ...
What do you mean by b/w?
You are expecting the data to be print in format like:
pdev->dev/name: mram_base %p sidf 0x%x %d xidf 0x%x %d rxf0 0x%x %d rxf1 0x%x %d rxb 0x%x %d txe 0x%x %d txb 0x%x %d
But when we use the dev_dbg()/pr_debug()... It will put data like:
pdev->dev/name: mram_base %p sidf 0x%x
0x%x %d rxf0 0x%x
rxf1 0x%x %d rxb
....
check this by enable DEBUG...
+ return 0;
+}
+
(...)
+
+static void unregister_m_can_dev(struct net_device *dev)
+{
+ unregister_candev(dev);
+}
+
again a function which calls a single func.
+static int m_can_plat_remove(struct platform_device *pdev)
+{
+ struct net_device *dev = platform_get_drvdata(pdev);
+
+ unregister_m_can_dev(dev);
+ platform_set_drvdata(pdev, NULL);
+
+ free_m_can_dev(dev);
+
+ return 0;
+}
+
+static const struct dev_pm_ops m_can_pmops = {
+ SET_SYSTEM_SLEEP_PM_OPS(m_can_suspend, m_can_resume)
+};
+
+static struct platform_driver m_can_plat_driver = {
+ .driver = {
+ .name = KBUILD_MODNAME,
+ .owner = THIS_MODULE,
No need to update .owner. module_platform_driver() will do for you.
see:http://lxr.free-electrons.com/source/include/linux/platform_device.h#L190
Oh, right.
+ .of_match_table = of_match_ptr(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>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("CAN bus driver for Bosch M_CAN controller");
Marc
--
Regards,
Varka Bhadram.
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
