> -----Original Message----- > From: Vladimir Zapolskiy [mailto:vladimir_zapolskiy@xxxxxxxxxx] > Sent: Wednesday, July 18, 2018 3:58 PM > To: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>; Shawn Guo > <shawnguo@xxxxxxxxxx>; Fabio Estevam <fabio.estevam@xxxxxxx>; Rob > Herring <robh+dt@xxxxxxxxxx>; Mark Rutland <mark.rutland@xxxxxxx>; A.s. > Dong <aisheng.dong@xxxxxxx> > Cc: kernel@xxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; > devicetree@xxxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx> > Subject: Re: [PATCH v4 4/4] mailbox: Add support for i.MX7D messaging unit > > Hi Oleksij, > > On 07/18/2018 10:12 AM, Oleksij Rempel wrote: > > The Mailbox controller is able to send messages (up to 4 32 bit words) > > between the endpoints. > > > > This driver was tested using the mailbox-test driver sending messages > > between the Cortex-A7 and the Cortex-M4. > > > > Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx> > > --- > > drivers/mailbox/Kconfig | 6 + > > drivers/mailbox/Makefile | 2 + > > drivers/mailbox/imx-mailbox.c | 300 > > ++++++++++++++++++++++++++++++++++ > > 3 files changed, 308 insertions(+) > > create mode 100644 drivers/mailbox/imx-mailbox.c > > > > diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig index > > a2bb27446dce..79060ddc380d 100644 > > --- a/drivers/mailbox/Kconfig > > +++ b/drivers/mailbox/Kconfig > > @@ -15,6 +15,12 @@ config ARM_MHU > > The controller has 3 mailbox channels, the last of which can be > > used in Secure mode only. > > > > +config IMX_MBOX > > + tristate "i.MX Mailbox" > > + depends on ARCH_MXC || COMPILE_TEST > > + help > > + Mailbox implementation for i.MX Messaging Unit (MU). > > + > > config PLATFORM_MHU > > tristate "Platform MHU Mailbox" > > depends on OF > > diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile index > > cc23c3a43fcd..ba2fe1b6dd62 100644 > > --- a/drivers/mailbox/Makefile > > +++ b/drivers/mailbox/Makefile > > @@ -7,6 +7,8 @@ obj-$(CONFIG_MAILBOX_TEST) += mailbox-test.o > > > > obj-$(CONFIG_ARM_MHU) += arm_mhu.o > > > > +obj-$(CONFIG_IMX_MBOX) += imx-mailbox.o > > + > > obj-$(CONFIG_PLATFORM_MHU) += platform_mhu.o > > > > obj-$(CONFIG_PL320_MBOX) += pl320-ipc.o > > diff --git a/drivers/mailbox/imx-mailbox.c > > b/drivers/mailbox/imx-mailbox.c new file mode 100644 index > > 000000000000..ad8797127b1f > > --- /dev/null > > +++ b/drivers/mailbox/imx-mailbox.c > > @@ -0,0 +1,300 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * Copyright (c) 2018 Pengutronix, Oleksij Rempel > > +<o.rempel@xxxxxxxxxxxxxx> */ > > + > > +#include <linux/clk.h> > > +#include <linux/interrupt.h> > > +#include <linux/io.h> > > +#include <linux/kernel.h> > > +#include <linux/mailbox_controller.h> #include <linux/module.h> > > +#include <linux/of_device.h> > > + > > +/* Transmit Register */ > > +#define IMX_MU_xTRn(x) (0x00 + 4 * (x)) > > +/* Receive Register */ > > +#define IMX_MU_xRRn(x) (0x10 + 4 * (x)) > > +/* Status Register */ > > +#define IMX_MU_xSR 0x20 > > +#define IMX_MU_xSR_TEn(x) BIT(20 + (3 - (x))) > > +#define IMX_MU_xSR_RFn(x) BIT(24 + (3 - (x))) > > +#define IMX_MU_xSR_BRDIP BIT(9) > > + > > +/* Control Register */ > > +#define IMX_MU_xCR 0x24 > > +/* Transmit Interrupt Enable */ > > +#define IMX_MU_xCR_TIEn(x) BIT(20 + (3 - (x))) > > +/* Receive Interrupt Enable */ > > +#define IMX_MU_xCR_RIEn(x) BIT(24 + (3 - (x))) > > + > > +#define IMX_MU_MAX_CHANS 4u > > + > > +struct imx_mu_priv; > > + > > +struct imx_mu_cfg { > > + unsigned int chans; > > Basically this field is not used, everywhere in the driver its usage can be > replaced by IMX_MU_MAX_CHANS, and it makes sense to rename the latter, > and 'chan' local variable from .probe is also removed. > > I suggest that you add this field at the time when you to add controller > specific data other than 'imx_mu_cfg_generic'. > > > + void (*init_hw)(struct imx_mu_priv *priv); }; > > + > > +struct imx_mu_con_priv { > > + int irq; > > + unsigned int idx; > > + char *irq_desc; > > +}; > > + > > +struct imx_mu_priv { > > + struct device *dev; > > + const struct imx_mu_cfg *dcfg; > > + void __iomem *base; > > + > > + struct mbox_controller mbox; > > + struct mbox_chan mbox_chans[IMX_MU_MAX_CHANS]; > > + > > + struct imx_mu_con_priv con_priv[IMX_MU_MAX_CHANS]; > > + struct clk *clk; > > + > > + bool side_b; > > +}; > > + > > +static struct imx_mu_priv *to_imx_mu_priv(struct mbox_controller > > +*mbox) { > > + return container_of(mbox, struct imx_mu_priv, mbox); } > > + > > +static void imx_mu_write(struct imx_mu_priv *priv, u32 val, u32 offs) > > +{ > > + iowrite32(val, priv->base + offs); > > +} > > + > > +static u32 imx_mu_read(struct imx_mu_priv *priv, u32 offs) { > > + return ioread32(priv->base + offs); > > +} > > + > > +static u32 imx_mu_rmw(struct imx_mu_priv *priv, u32 offs, u32 set, > > +u32 clr) { > > + u32 val; > > + > > + val = imx_mu_read(priv, offs); > > + val &= ~clr; > > + val |= set; > > + imx_mu_write(priv, val, offs); > > + > > + return val; > > +} > > + > > +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; > > + > > + ctrl = imx_mu_read(priv, IMX_MU_xCR); > > + val = imx_mu_read(priv, IMX_MU_xSR); > > + val &= IMX_MU_xSR_TEn(cp->idx) | IMX_MU_xSR_RFn(cp->idx); > > + val &= ctrl & (IMX_MU_xCR_TIEn(cp->idx) | IMX_MU_xCR_RIEn(cp- > >idx)); > > + if (!val) > > + return IRQ_NONE; > > + > > + if (val & IMX_MU_xSR_TEn(cp->idx)) { > > + imx_mu_rmw(priv, IMX_MU_xCR, 0, IMX_MU_xCR_TIEn(cp- > >idx)); > > + mbox_chan_txdone(chan, 0); > > + } > > + > > + if (val & IMX_MU_xSR_RFn(cp->idx)) { > > + dat = imx_mu_read(priv, IMX_MU_xRRn(cp->idx)); > > + mbox_chan_received_data(chan, (void *)&dat); > > + } > > + > > + return IRQ_HANDLED; > > +} > > + > > +static bool imx_mu_last_tx_done(struct mbox_chan *chan) { > > + struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox); > > + struct imx_mu_con_priv *cp = chan->con_priv; > > + u32 val; > > + > > + val = imx_mu_read(priv, IMX_MU_xSR); > > + /* test if transmit register is empty */ > > + return (!!(val & IMX_MU_xSR_TEn(cp->idx))); > > Because the function returns bool value, double negation is not needed. > > return val & IMX_MU_xSR_TEn(cp->idx); > > is good enough. > > > +} > > + > > +static int imx_mu_send_data(struct mbox_chan *chan, void *data) { > > + struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox); > > + struct imx_mu_con_priv *cp = chan->con_priv; > > + u32 *arg = data; > > + > > + if (!imx_mu_last_tx_done(chan)) > > + return -EBUSY; > > + > > + imx_mu_write(priv, *arg, IMX_MU_xTRn(cp->idx)); > > + imx_mu_rmw(priv, IMX_MU_xCR, IMX_MU_xSR_TEn(cp->idx), 0); > > + > > + return 0; > > +} > > + > > +static int imx_mu_startup(struct mbox_chan *chan) { > > + struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox); > > + struct imx_mu_con_priv *cp = chan->con_priv; > > + int ret; > > + > > + cp->irq_desc = devm_kasprintf(priv->dev, GFP_KERNEL, > "imx_mu_chan[%i]", > > + cp->idx); > > + if (!cp->irq_desc) > > + return -ENOMEM; > > + > > + ret = devm_request_irq(priv->dev, cp->irq, imx_mu_isr, > > + IRQF_SHARED, cp->irq_desc, chan); > > + if (ret) { > > + dev_err(priv->dev, > > + "Unable to acquire IRQ %d\n", cp->irq); > > + return ret; > > + } > > + > > + imx_mu_rmw(priv, IMX_MU_xCR, IMX_MU_xCR_RIEn(cp->idx), 0); > > + > > + return 0; > > +} > > + > > +static void imx_mu_shutdown(struct mbox_chan *chan) { > > + struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox); > > + struct imx_mu_con_priv *cp = chan->con_priv; > > + > > + imx_mu_rmw(priv, IMX_MU_xCR, 0, > > + IMX_MU_xCR_TIEn(cp->idx) | IMX_MU_xCR_RIEn(cp- > >idx)); > > + > > + devm_free_irq(priv->dev, cp->irq, chan); > > + devm_kfree(priv->dev, cp->irq_desc); } > > + > > +static const struct mbox_chan_ops imx_mu_ops = { > > + .send_data = imx_mu_send_data, > > + .startup = imx_mu_startup, > > + .shutdown = imx_mu_shutdown, > > +}; > > + > > +static int imx_mu_probe(struct platform_device *pdev) { > > + struct device *dev = &pdev->dev; > > + struct device_node *np = dev->of_node; > > + struct resource *iomem; > > + struct imx_mu_priv *priv; > > + const struct imx_mu_cfg *dcfg; > > + unsigned int i, chans; > > + int irq, ret; > > + > > + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); > > + if (!priv) > > + return -ENOMEM; > > + > > + dcfg = of_device_get_match_data(dev); > > + if (!dcfg) > > + return -EINVAL; > > + > > + priv->dcfg = dcfg; > > + priv->dev = dev; > > + > > + iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0); > > + priv->base = devm_ioremap_resource(&pdev->dev, iomem); > > + if (IS_ERR(priv->base)) > > + return PTR_ERR(priv->base); > > + > > + irq = platform_get_irq(pdev, 0); > > + if (irq <= 0) > > + return irq < 0 ? irq : -EINVAL; > > Please don't check or handle 'irq == 0' case specially, it is dead code. > > if (irq < 0) > return irq; > > is good enough. > > > + > > + priv->clk = devm_clk_get(dev, NULL); > > + if (IS_ERR(priv->clk)) { > > + if (PTR_ERR(priv->clk) != -ENOENT) > > + return PTR_ERR(priv->clk); > > + > > + priv->clk = NULL; > > + } > > + > > + ret = clk_prepare_enable(priv->clk); > > + if (ret) { > > + dev_err(dev, "Failed to enable clock\n"); > > + return ret; > > + } > > + > > + chans = min(dcfg->chans, IMX_MU_MAX_CHANS); > > + /* Initialize channel identifiers */ > > The comment above is trivial, please remove it. > > > + for (i = 0; i < chans; i++) { > > + struct imx_mu_con_priv *cp = &priv->con_priv[i]; > > + > > + cp->idx = i; > > + cp->irq = irq; > > I read it as a single irq for all channels. > > Why do you dynamically init more channel data imx_mu_startup() based on > irq value? > Aren't 'cp->irq_desc' all equal? Isn't just a single devm_request_irq() > in .probe sufficient? They're used to differentiate the channel irq name (probably initialize here is enough). And the code replies on devm_request_irq to pass the corresponding data of each channel, That why calls request_irq multiple times. > > > + priv->mbox_chans[i].con_priv = cp; > > + } > > + > > + if (of_property_read_bool(np, "fsl,mu-side-b")) > > + priv->side_b = true; > > + > > + priv->mbox.dev = dev; > > + priv->mbox.ops = &imx_mu_ops; > > + priv->mbox.chans = priv->mbox_chans; > > + priv->mbox.num_chans = chans; > > + priv->mbox.txdone_irq = true; > > + > > + platform_set_drvdata(pdev, priv); > > + > > + if (priv->dcfg->init_hw) > > + priv->dcfg->init_hw(priv); > > + > > + return mbox_controller_register(&priv->mbox); > > +} > > + > > +static int imx_mu_remove(struct platform_device *pdev) { > > + struct imx_mu_priv *priv = platform_get_drvdata(pdev); > > + > > + mbox_controller_unregister(&priv->mbox); > > + clk_disable_unprepare(priv->clk); > > + > > + return 0; > > +} > > + > > +static void imx_mu_init_generic(struct imx_mu_priv *priv) { > > + if (priv->side_b) > > + return; > > + > > + /* Set default MU configuration */ > > + imx_mu_write(priv, 0, IMX_MU_xCR); > > +} > > + > > +static const struct imx_mu_cfg imx_mu_cfg_generic = { > > + .chans = IMX_MU_MAX_CHANS, > > Here IMX_MU_MAX_CHANS macro name is questionable, see my top > comment. > For clarity here 'MAX' is not expected, it shall be the exact controller specific > value, something like s/MAX/NUM/ may be considered. > I actually gave the same suggestion in last round review, but Oleksij seems have his own reason and insist to keep it. I even suggest to totally remove struct imx_mu_cfg now and add it later once we see real requirement. > > + .init_hw = imx_mu_init_generic, > > +}; > > + > > +static const struct of_device_id imx_mu_dt_ids[] = { > > + { .compatible = "fsl,imx6sx-mu", .data = &imx_mu_cfg_generic }, > > + { .compatible = "fsl,imx7d-mu", .data = &imx_mu_cfg_generic }, > > + { .compatible = "fsl,imx7s-mu", .data = &imx_mu_cfg_generic }, 7d and 7s should be the same. > > + { .compatible = "fsl,imx7ulp-mu", .data = &imx_mu_cfg_generic }, > > + { .compatible = "fsl,imx8qm-mu", .data = &imx_mu_cfg_generic }, > > + { .compatible = "fsl,imx8qxp-mu", .data = &imx_mu_cfg_generic }, > > It sounds like the list will be constantly extending. Is there any chance to > introduce just one generic compatible in the driver, and describe the whole > set of compatibles in documentation section only? > I think only keeping "fsl,imx6sx-mu" should be enough. The ulp is slightly different, but could be extended later. Regards Dong Aisheng > > + { }, > > +}; > > +MODULE_DEVICE_TABLE(of, imx_mu_dt_ids); > > + > > +static struct platform_driver imx_mu_driver = { > > + .probe = imx_mu_probe, > > + .remove = imx_mu_remove, > > + .driver = { > > + .name = "imx_mu", > > + .of_match_table = imx_mu_dt_ids, > > + }, > > +}; > > +module_platform_driver(imx_mu_driver); > > + > > +MODULE_AUTHOR("Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>"); > > +MODULE_DESCRIPTION("Message Unit driver for i.MX"); > > +MODULE_LICENSE("GPL v2"); > > > > -- > Best wishes, > Vladimir -- 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
