Re: [PATCH linux-next v4 5/5] mtd: atmel-quadspi: add driver for Atmel QSPI controller

Marek Vasut
2015-08-24T11:03:59Z

On Monday, August 24, 2015 at 12:14:00 PM, Cyrille Pitchen wrote:
> This driver add support to the new Atmel QSPI controller embedded into
> sama5d2x SoCs. It expects a NOR memory to be connected to the QSPI
> controller.
>
> Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>

Hi,

[...]

> +/* Register access macros */

These are functions, not macros :)

btw is there any reason for these ? I'd say, just put the read*() and
write*() functions directly into the code and be done with it, it is
much less confusing.

Also, why do you use the _relaxed() versions of the functions ?

> +static inline u32 qspi_readl(struct atmel_qspi *aq, u32 reg)
> +{
> + return readl_relaxed(aq->regs + reg);
> +}
> +
> +static inline void qspi_writel(struct atmel_qspi *aq, u32 reg, u32 value)
> +{
> + writel_relaxed(value, aq->regs + reg);
> +}
> +
> +static inline u16 qspi_readw(struct atmel_qspi *aq, u32 reg)
> +{
> + return readw_relaxed(aq->regs + reg);
> +}
> +
> +static inline void qspi_writew(struct atmel_qspi *aq, u32 reg, u16 value)
> +{
> + writew_relaxed(value, aq->regs + reg);
> +}
> +
> +static inline u8 qspi_readb(struct atmel_qspi *aq, u32 reg)
> +{
> + return readb_relaxed(aq->regs + reg);
> +}
> +
> +static inline void qspi_writeb(struct atmel_qspi *aq, u32 reg, u8 value)
> +{
> + writeb_relaxed(value, aq->regs + reg);
> +}

[...]

> +static int atmel_qspi_run_command(struct atmel_qspi *aq,
> + const struct atmel_qspi_command *cmd)
> +{
> + u32 iar, icr, ifr, sr;
> + int err = 0;
> +
> + iar = 0;
> + icr = 0;
> + ifr = aq->ifr_width | cmd->ifr_tfrtyp;
> +
> + /* Compute instruction parameters */
> + if (cmd->enable.bits.instruction) {
> + icr |= QSPI_ICR_INST(cmd->instruction);
> + ifr |= QSPI_IFR_INSTEN;
> + }
> +
> + /* Compute address parameters */
> + switch (cmd->enable.bits.address) {
> + case 4:
> + ifr |= QSPI_IFR_ADDRL;
> + /*break;*/ /* fallback to the 24bit address case */

What's this commented out bit of code for ? :-)

> + case 3:
> + iar = (cmd->enable.bits.data) ? 0 : cmd->address;
> + ifr |= QSPI_IFR_ADDREN;
> + break;
> + case 0:
> + break;
> + default:
> + return -EINVAL;
> + }

[...]

> +no_data:
> + /* Poll INSTRuction End status */
> + sr = qspi_readl(aq, QSPI_SR);
> + if (sr & QSPI_SR_INSTRE)
> + return err;
> +
> + /* Wait for INSTRuction End interrupt */
> + init_completion(&aq->completion);

You should use reinit_completion() in the code. init_completion()
should be used only in the probe() function and nowhere else.

> + aq->pending = 0;
> + qspi_writel(aq, QSPI_IER, QSPI_SR_INSTRE);
> + if (!wait_for_completion_timeout(&aq->completion,
> + msecs_to_jiffies(1000)))
> + err = -ETIMEDOUT;
> + qspi_writel(aq, QSPI_IDR, QSPI_SR_INSTRE);
> +
> + return err;
> +}

[...]

Hope this helps :)