On 12/18/2015 09:17 PM, Damien Riegel wrote:
> Technologic Systems provides an IP compatible with the SJA1000,
> instantiated in an FPGA. Because of some bus widths issue, access to
> registers is made through a "window" that works like this:
>
> base + 0x0: address to read/write
> base + 0x2: 8-bit register value
>
> This commit adds a new compatible device, "technologic,sja1000", with
> read and write functions using the window mechanism.
>
> Signed-off-by: Damien Riegel <damien.riegel@xxxxxxxxxxxxxxxxxxxx>
> ---
> drivers/net/can/sja1000/sja1000_platform.c | 30 ++++++++++++++++++++++++++++--
> 1 file changed, 28 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/can/sja1000/sja1000_platform.c b/drivers/net/can/sja1000/sja1000_platform.c
> index 0552ed4..6cbf251 100644
> --- a/drivers/net/can/sja1000/sja1000_platform.c
> +++ b/drivers/net/can/sja1000/sja1000_platform.c
> @@ -70,6 +70,18 @@ static void sp_write_reg32(const struct sja1000_priv *priv, int reg, u8 val)
> iowrite8(val, priv->reg_base + reg * 4);
> }
>
> +static u8 ts4800_read_reg16(const struct sja1000_priv *priv, int reg)
> +{
> + sp_write_reg16(priv, 0, reg);
> + return sp_read_reg16(priv, 2);
This is racy, please add a spinlock.
> +}
> +
> +static void ts4800_write_reg16(const struct sja1000_priv *priv, int reg, u8 val)
> +{
> + sp_write_reg16(priv, 0, reg);
> + sp_write_reg16(priv, 2, val);
This is racy, too.
Have a look at https://marc.info/?l=linux-can&m=137149497403825&w=2
Marc
> +}
> +
> static void sp_populate(struct sja1000_priv *priv,
> struct sja1000_platform_data *pdata,
> unsigned long resource_mem_flags)
> @@ -98,21 +110,34 @@ static void sp_populate(struct sja1000_priv *priv,
>
> static void sp_populate_of(struct sja1000_priv *priv, struct device_node *of)
> {
> + int is_technologic;
> int err;
> u32 prop;
>
> + is_technologic = of_device_is_compatible(of, "technologic,sja1000");
> +
> err = of_property_read_u32(of, "reg-io-width", &prop);
> if (err)
> prop = 1; /* 8 bit is default */
>
> + if (is_technologic && prop != 2) {
> + netdev_warn(priv->dev, "forcing reg-io-width to 2\n");
> + prop = 2;
> + }
> +
> switch (prop) {
> case 4:
> priv->read_reg = sp_read_reg32;
> priv->write_reg = sp_write_reg32;
> break;
> case 2:
> - priv->read_reg = sp_read_reg16;
> - priv->write_reg = sp_write_reg16;
> + if (is_technologic) {
> + priv->read_reg = ts4800_read_reg16;
> + priv->write_reg = ts4800_write_reg16;
> + } else {
> + priv->read_reg = sp_read_reg16;
> + priv->write_reg = sp_write_reg16;
> + }
> break;
> case 1: /* fallthrough */
> default:
> @@ -244,6 +269,7 @@ static int sp_remove(struct platform_device *pdev)
>
> static const struct of_device_id sp_of_table[] = {
> {.compatible = "nxp,sja1000"},
> + {.compatible = "technologic,sja1000"},
> {},
> };
> MODULE_DEVICE_TABLE(of, sp_of_table);
>
--
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