Hi Oleksij, > -----Original Message----- > From: Oleksij Rempel [mailto:o.rempel@xxxxxxxxxxxxxx] > Sent: Friday, June 15, 2018 5:51 PM > To: 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: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>; kernel@xxxxxxxxxxxxxx; > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux- > clk@xxxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx> > Subject: [PATCH v2 4/4] mailbox: Add support for i.MX7D messaging unit > > The Mailbox controller is able to send messages (up to 4 32 bit words) > between the endpoints. > This is not correct according to current implementation as we abstract them into 4 virtual channels while each 'channel' can send only one word one time. We probably need explain such limitation in commit message as well. I'm not strongly against this way. But it makes the controller lose the HW capability to send up to 4 words. I'd just like to know a bit history or reason why we decided to do that. Do we design it for specific users case for M4? And are we assuming there will be no real users of multi words send requirement? > 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 | 288 > ++++++++++++++++++++++++++++++++++ > 3 files changed, 296 insertions(+) > create mode 100644 drivers/mailbox/imx-mailbox.c > > diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig index > a2bb27446dce..e1d2738a2e4c 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 "iMX Mailbox" > + depends on SOC_IMX7D || COMPILE_TEST Better change to ARCH_MXC as other platform does. > + help > + Mailbox implementation for iMX7D Messaging Unit (MU). Ditto > + > 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..e3f621cb1d30 > --- /dev/null > +++ b/drivers/mailbox/imx-mailbox.c > @@ -0,0 +1,288 @@ > +// 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 + (x)) > +#define IMX_MU_xSR_RFn(x) BIT(24 + (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 + (x)) > +/* Receive Interrupt Enable */ > +#define IMX_MU_xCR_RIEn(x) BIT(24 + (x)) > + > +#define IMX_MU_MAX_CHANS 4u > + > +struct imx_mu_priv; > + > +struct imx_mu_cfg { > + unsigned int chans; > + void (*init_hw)(struct imx_mu_priv *priv); }; > + > +struct imx_mu_con_priv { > + int irq; > + unsigned int bidx; > + unsigned int idx; > +}; > + > +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; > +}; > + > +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, dat; > + > + val = imx_mu_read(priv, IMX_MU_xSR); > + val &= IMX_MU_xSR_TEn(cp->bidx) | IMX_MU_xSR_RFn(cp->bidx); > + if (!val) > + return IRQ_NONE; > + > + if (val & IMX_MU_xSR_TEn(cp->bidx)) { > + imx_mu_rmw(priv, IMX_MU_xCR, 0, IMX_MU_xCR_TIEn(cp- > >bidx)); > + mbox_chan_txdone(chan, 0); > + } > + > + if (val & IMX_MU_xSR_RFn(cp->bidx)) { > + 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->bidx))); } > + > +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->bidx), 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; > + > + ret = request_irq(cp->irq, imx_mu_isr, > + IRQF_SHARED, "imx_mu_chan", chan); I guess no need to assign the irq for each cp as we have only one irq. > + if (ret) { > + dev_err(chan->mbox->dev, > + "Unable to acquire IRQ %d\n", cp->irq); > + return ret; > + } > + > + imx_mu_rmw(priv, IMX_MU_xCR, IMX_MU_xCR_RIEn(cp->bidx), 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->bidx) | IMX_MU_xCR_RIEn(cp- > >bidx)); > + > + free_irq(cp->irq, chan); > +} > + > +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 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; > + > + priv->clk = devm_clk_get(dev, NULL); > + if (IS_ERR(priv->clk)) { > + if (PTR_ERR(priv->clk) == -ENOENT) { > + priv->clk = NULL; > + } else { > + dev_err(dev, "Failed to get clock\n"); I guess we may not need print it for DEFER_PROBE error case. > + return PTR_ERR(priv->clk); > + } > + } > + > + 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 */ > + for (i = 0; i < chans; i++) { > + struct imx_mu_con_priv *cp = &priv->con_priv[i]; > + > + cp->bidx = 3 - i; We may not need it if we improve the macro to calculate bidx by idx? > + cp->idx = i; > + cp->irq = irq; > + priv->mbox_chans[i].con_priv = cp; > + } > + > + 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_imx7d_a(struct imx_mu_priv *priv) { > + /* Set default config */ > + imx_mu_write(priv, 0, IMX_MU_xCR); This will reset both MU Side A and B. So we may need make sure Side B is initialized after A? > +} > + > +static const struct imx_mu_cfg imx_mu_cfg_imx7d_a = { > + .chans = IMX_MU_MAX_CHANS, > + .init_hw = imx_mu_init_imx7d_a, > +}; > + > +static const struct imx_mu_cfg imx_mu_cfg_imx7d_b = { > + .chans = IMX_MU_MAX_CHANS, > +}; > + > +static const struct of_device_id imx_mu_dt_ids[] = { > + { .compatible = "fsl,imx7s-mu-a", .data = &imx_mu_cfg_imx7d_a }, > + { .compatible = "fsl,imx7s-mu-b", .data = &imx_mu_cfg_imx7d_b }, I'm not sure whether we already have the decision to use fsl,<soc>-mu compatible String and use property to specify the mu side. Can you double check if we can switch to that way? And would you update the binding doc for M4 support according to the qxp mu one Which Is already signed by Rob's tag? 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"); > -- > 2.17.1 -- 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
