Re: [PATCH 5/5] can: flexcan: add mcf5441x support

Marc Kleine-Budde
2021-06-09T08:56:35Z

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On 08.06.2021 22:45:42, Angelo Dureghello wrote:
> Add flexcan support for NXP ColdFire mcf5441x family.
>
> This flexcan module is quite similar to imx6 flexcan module, but
> with some exceptions:
>
> - 3 separate interrupt sources, MB, BOFF and ERR,

Please don't hard code the 2 extra interrupts as offsets, but create
proper IRQ resources.

> - implements 16 mb only,
> - m68k architecture is not supporting devicetrees, so a
> platform data check/case has been added,

You might want to revert:

| 2c0ac9208135 can: flexcan: convert the driver to DT-only

and use it as a starting point.

> - ColdFire is m68k, so big-endian cpu, with a little-endian flexcan
> module.
>
> Signed-off-by: Angelo Dureghello <angelo@kernel-space.org>
> ---
> drivers/net/can/flexcan.c | 80 +++++++++++++++++++++++++++++++--------
> 1 file changed, 65 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
> index 57f3635ad8d7..af95273327cd 100644
> --- a/drivers/net/can/flexcan.c
> +++ b/drivers/net/can/flexcan.c
> @@ -28,6 +28,7 @@
> #include <linux/of_device.h>
> #include <linux/pinctrl/consumer.h>
> #include <linux/platform_device.h>
> +#include <linux/platform_data/flexcan-mcf.h>
> #include <linux/pm_runtime.h>
> #include <linux/regmap.h>
> #include <linux/regulator/consumer.h>
> @@ -205,6 +206,10 @@
>
> #define FLEXCAN_TIMEOUT_US (250)
>
> +#define FLEXCAN_OFFS_INT_BOFF 1
> +#define FLEXCAN_OFFS_INT_ERR 3
> +#define FLEXCAN_MB_CNT_MCF 16
> +
> /* FLEXCAN hardware feature flags
> *
> * Below is some version info we got:
> @@ -246,6 +251,8 @@
> #define FLEXCAN_QUIRK_SUPPORT_ECC BIT(10)
> /* Setup stop mode with SCU firmware to support wakeup */
> #define FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW BIT(11)
> +/* Setup for flexcan module as in mcf, 16 mb, 3 separate interrupts */
> +#define FLEXCAN_QUIRK_SETUP_MCF BIT(12)
>
> /* Structure of the message buffer */
> struct flexcan_mb {
> @@ -371,6 +378,12 @@ struct flexcan_priv {
> void (*write)(u32 val, void __iomem *addr);
> };
>
> +static const struct flexcan_devtype_data fsl_mcf_devtype_data = {
> + .quirks = FLEXCAN_QUIRK_BROKEN_WERR_STATE |
> + FLEXCAN_QUIRK_BROKEN_PERR_STATE |
> + FLEXCAN_QUIRK_SETUP_MCF,
> +};
> +
> static const struct flexcan_devtype_data fsl_p1010_devtype_data = {
> .quirks = FLEXCAN_QUIRK_BROKEN_WERR_STATE |
> FLEXCAN_QUIRK_BROKEN_PERR_STATE |
> @@ -637,13 +650,17 @@ static int flexcan_clks_enable(const struct flexcan_priv *priv)
> {
> int err;
>
> - err = clk_prepare_enable(priv->clk_ipg);
> - if (err)
> - return err;
> + if (priv->clk_ipg) {
> + err = clk_prepare_enable(priv->clk_ipg);
> + if (err)
> + return err;
> + }
>
> - err = clk_prepare_enable(priv->clk_per);
> - if (err)
> - clk_disable_unprepare(priv->clk_ipg);
> + if (priv->clk_per) {
> + err = clk_prepare_enable(priv->clk_per);
> + if (err)
> + clk_disable_unprepare(priv->clk_ipg);
> + }
>
> return err;
> }
> @@ -1401,8 +1418,13 @@ static int flexcan_rx_offload_setup(struct net_device *dev)
> priv->mb_size = sizeof(struct flexcan_mb) + CANFD_MAX_DLEN;
> else
> priv->mb_size = sizeof(struct flexcan_mb) + CAN_MAX_DLEN;
> - priv->mb_count = (sizeof(priv->regs->mb[0]) / priv->mb_size) +
> - (sizeof(priv->regs->mb[1]) / priv->mb_size);
> +
> + if (priv->devtype_data->quirks & FLEXCAN_QUIRK_SETUP_MCF) {
> + priv->mb_count = FLEXCAN_MB_CNT_MCF;
> + } else {
> + priv->mb_count = (sizeof(priv->regs->mb[0]) / priv->mb_size) +
> + (sizeof(priv->regs->mb[1]) / priv->mb_size);
> + }

nitpick: no { } needed

>
> if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)
> priv->tx_mb_reserved =
> @@ -1774,6 +1796,18 @@ static int flexcan_open(struct net_device *dev)
> if (err)
> goto out_can_rx_offload_disable;
>
> + if (priv->devtype_data->quirks & FLEXCAN_QUIRK_SETUP_MCF) {
> + err = request_irq(dev->irq + FLEXCAN_OFFS_INT_BOFF,
> + flexcan_irq, IRQF_SHARED, dev->name, dev);
> + if (err)
> + goto out_can_rx_offload_disable;
> +
> + err = request_irq(dev->irq + FLEXCAN_OFFS_INT_ERR,
> + flexcan_irq, IRQF_SHARED, dev->name, dev);
> + if (err)
> + goto out_can_rx_offload_disable;

I'm missing the free_irq() in error handling and the flexcan_close()
function. Please test your driver if it work still after several
modprobe rmmod cycles.

> + }
> +
> flexcan_chip_interrupts_enable(dev);
>
> can_led_event(dev, CAN_LED_EVENT_OPEN);
> @@ -2047,7 +2081,9 @@ static int flexcan_probe(struct platform_device *pdev)
> struct regulator *reg_xceiver;
> struct clk *clk_ipg = NULL, *clk_per = NULL;
> struct flexcan_regs __iomem *regs;
> + struct mcf_flexcan_platform_data *pdata;
> int err, irq;
> + bool big_endian_module;
> u8 clk_src = 1;
> u32 clock_freq = 0;
>
> @@ -2059,11 +2095,17 @@ static int flexcan_probe(struct platform_device *pdev)
> else if (IS_ERR(reg_xceiver))
> return PTR_ERR(reg_xceiver);
>
> - if (pdev->dev.of_node) {
> - of_property_read_u32(pdev->dev.of_node,
> - "clock-frequency", &clock_freq);
> - of_property_read_u8(pdev->dev.of_node,
> - "fsl,clk-source", &clk_src);
> + pdata = dev_get_platdata(&pdev->dev);
> + if (pdata) {
> + clock_freq = pdata->clock_frequency;
> + clk_src = pdata->clk_src;
> + } else {
> + if (pdev->dev.of_node) {

else if

> + of_property_read_u32(pdev->dev.of_node,
> + "clock-frequency", &clock_freq);
> + of_property_read_u8(pdev->dev.of_node,
> + "fsl,clk-source", &clk_src);
> + }
> }
>
> if (!clock_freq) {
> @@ -2091,6 +2133,11 @@ static int flexcan_probe(struct platform_device *pdev)
>
> devtype_data = of_device_get_match_data(&pdev->dev);
>
> + if (pdata && !devtype_data) {
> + devtype_data =
> + (struct flexcan_devtype_data *)&fsl_mcf_devtype_data;

That looks broken, see 2c0ac9208135 how to do this properly. Please add a
name "flexcan-mcf" to the id_table and use fsl_mcf_devtype_data as
driver_data.

> + }
> +
> if ((devtype_data->quirks & FLEXCAN_QUIRK_SUPPORT_FD) &&
> !(devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)) {
> dev_err(&pdev->dev, "CAN-FD mode doesn't work with FIFO mode!\n");
> @@ -2110,8 +2157,11 @@ static int flexcan_probe(struct platform_device *pdev)
>
> priv = netdev_priv(dev);
>
> - if (of_property_read_bool(pdev->dev.of_node, "big-endian") ||
> - devtype_data->quirks & FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN) {
> + big_endian_module = pdata ? pdata->big_endian :
> + of_property_read_bool(pdev->dev.of_node, "big-endian");

Please add the FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN to you
fsl_mcf_devtype_data if needed. There's no need to add a 3rd way of
configuring this.

> +
> + if (big_endian_module ||
> + (devtype_data->quirks & FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN)) {
> priv->read = flexcan_read_be;
> priv->write = flexcan_write_be;
> } else {
> --
> 2.31.1
>
>

Marc

--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung West/Dortmund | Phone: +49-231-2826-924 |
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