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SubjectRe: [RFC] mailbox: imx: Add support for i.MX v1 messaging unit
On Fri, Jul 26, 2019 at 04:29:36PM +0800, Richard Zhu wrote:
> There is a version1.0 MU on i.MX7ULP platform.
> One new version ID register is added, and the offset is 0.
> TRn registers are defined at the offset 0x20 ~ 0x2C.
> RRn registers are defined at the offset 0x40 ~ 0x4C.
> SR/CR registers are defined at 0x60/0x64.
> Extend this driver to support it.

Heh.. i feel like NXP/Freescale have old tradition of moving around
registers and adding/removing the version register :)

Since it is not first time, I would prefer to have register layout
linked on probe and not calculating or if-ing it on runtime. Especially,
because I assume it is not the last layout change.

For example see:
https://elixir.bootlin.com/linux/v5.3-rc1/source/drivers/remoteproc/imx_rproc.c#L336
dcfg = of_device_get_match_data(dev);

or
https://elixir.bootlin.com/linux/v5.3-rc1/source/drivers/net/ethernet/atheros/ag71xx.c#L1651

and please, do not try to detect version by reading wrong register. We
have devicetree compatible for this use case.

> Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> ---
> drivers/mailbox/imx-mailbox.c | 45 +++++++++++++++++++++++++++++++++----------
> 1 file changed, 35 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/mailbox/imx-mailbox.c b/drivers/mailbox/imx-mailbox.c
> index 25be8bb..eb55bbe 100644
> --- a/drivers/mailbox/imx-mailbox.c
> +++ b/drivers/mailbox/imx-mailbox.c
> @@ -12,10 +12,14 @@
> #include <linux/of_device.h>
> #include <linux/slab.h>
>
> +#define MU_VER_ID_V1 0x0100
> +
> /* Transmit Register */
> #define IMX_MU_xTRn(x) (0x00 + 4 * (x))
> +#define IMX_MU_xTRn_V1(x) (0x20 + 4 * (x))
> /* Receive Register */
> #define IMX_MU_xRRn(x) (0x10 + 4 * (x))
> +#define IMX_MU_xRRn_V1(x) (0x40 + 4 * (x))
> /* Status Register */
> #define IMX_MU_xSR 0x20
> #define IMX_MU_xSR_GIPn(x) BIT(28 + (3 - (x)))
> @@ -25,6 +29,7 @@
>
> /* Control Register */
> #define IMX_MU_xCR 0x24
> +#define IMX_MU_xSCR_V1_OFFSET 0x40
> /* General Purpose Interrupt Enable */
> #define IMX_MU_xCR_GIEn(x) BIT(28 + (3 - (x)))
> /* Receive Interrupt Enable */
> @@ -63,6 +68,7 @@ struct imx_mu_priv {
> struct imx_mu_con_priv con_priv[IMX_MU_CHANS];
> struct clk *clk;
> int irq;
> + int version;
>
> bool side_b;
> };
> @@ -85,13 +91,16 @@ static u32 imx_mu_read(struct imx_mu_priv *priv, u32 offs)
> static u32 imx_mu_xcr_rmw(struct imx_mu_priv *priv, u32 set, u32 clr)
> {
> unsigned long flags;
> - u32 val;
> + u32 val, offset;
> +
> + offset = unlikely(priv->version == MU_VER_ID_V1) ?
> + IMX_MU_xSCR_V1_OFFSET : 0;
>
> spin_lock_irqsave(&priv->xcr_lock, flags);
> - val = imx_mu_read(priv, IMX_MU_xCR);
> + val = imx_mu_read(priv, IMX_MU_xCR + offset);
> val &= ~clr;
> val |= set;
> - imx_mu_write(priv, val, IMX_MU_xCR);
> + imx_mu_write(priv, val, IMX_MU_xCR + offset);
> spin_unlock_irqrestore(&priv->xcr_lock, flags);
>
> return val;
> @@ -109,10 +118,13 @@ static irqreturn_t imx_mu_isr(int irq, void *p)
> struct mbox_chan *chan = p;
> struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
> struct imx_mu_con_priv *cp = chan->con_priv;
> - u32 val, ctrl, dat;
> + u32 val, ctrl, dat, offset;
> +
> + offset = unlikely(priv->version == MU_VER_ID_V1) ?
> + IMX_MU_xSCR_V1_OFFSET : 0;
>
> - ctrl = imx_mu_read(priv, IMX_MU_xCR);
> - val = imx_mu_read(priv, IMX_MU_xSR);
> + ctrl = imx_mu_read(priv, IMX_MU_xCR + offset);
> + val = imx_mu_read(priv, IMX_MU_xSR + offset);
>
> switch (cp->type) {
> case IMX_MU_TYPE_TX:
> @@ -138,10 +150,14 @@ static irqreturn_t imx_mu_isr(int irq, void *p)
> imx_mu_xcr_rmw(priv, 0, IMX_MU_xCR_TIEn(cp->idx));
> mbox_chan_txdone(chan, 0);
> } else if (val == IMX_MU_xSR_RFn(cp->idx)) {
> - dat = imx_mu_read(priv, IMX_MU_xRRn(cp->idx));
> + if (unlikely(priv->version == MU_VER_ID_V1))
> + dat = imx_mu_read(priv, IMX_MU_xRRn_V1(cp->idx));
> + else
> + dat = imx_mu_read(priv, IMX_MU_xRRn(cp->idx));
> mbox_chan_received_data(chan, (void *)&dat);
> } else if (val == IMX_MU_xSR_GIPn(cp->idx)) {
> - imx_mu_write(priv, IMX_MU_xSR_GIPn(cp->idx), IMX_MU_xSR);
> + imx_mu_write(priv, IMX_MU_xSR_GIPn(cp->idx),
> + IMX_MU_xSR + offset);
> mbox_chan_received_data(chan, NULL);
> } else {
> dev_warn_ratelimited(priv->dev, "Not handled interrupt\n");
> @@ -159,7 +175,10 @@ static int imx_mu_send_data(struct mbox_chan *chan, void *data)
>
> switch (cp->type) {
> case IMX_MU_TYPE_TX:
> - imx_mu_write(priv, *arg, IMX_MU_xTRn(cp->idx));
> + if (unlikely(priv->version == MU_VER_ID_V1))
> + imx_mu_write(priv, *arg, IMX_MU_xTRn_V1(cp->idx));
> + else
> + imx_mu_write(priv, *arg, IMX_MU_xTRn(cp->idx));
> imx_mu_xcr_rmw(priv, IMX_MU_xCR_TIEn(cp->idx), 0);
> break;
> case IMX_MU_TYPE_TXDB:
> @@ -253,11 +272,17 @@ static struct mbox_chan * imx_mu_xlate(struct mbox_controller *mbox,
>
> static void imx_mu_init_generic(struct imx_mu_priv *priv)
> {
> + u32 offset;
> +
> if (priv->side_b)
> return;
>
> + priv->version = imx_mu_read(priv, 0) >> 16;
> + offset = unlikely(priv->version == MU_VER_ID_V1) ?
> + IMX_MU_xSCR_V1_OFFSET : 0;
> +
> /* Set default MU configuration */
> - imx_mu_write(priv, 0, IMX_MU_xCR);
> + imx_mu_write(priv, 0, IMX_MU_xCR + offset);
> }
>
> static int imx_mu_probe(struct platform_device *pdev)
> --
> 2.7.4
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>

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