| Message ID | 1466503374-28841-2-git-send-email-narmstrong@baylibre.com (mailing list archive) |
|---|---|
| State | RFC |
| Headers | show |
On Tue, Jun 21, 2016 at 3:32 PM, Neil Armstrong <narmstrong@baylibre.com> wrote: > Add Amlogic Meson SoCs Message-Handling-Unit as mailbox controller > with 2 independent channels/links to communicate with a remote processor. > > Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> ..... > +++ b/drivers/mailbox/meson_mhu.c > @@ -0,0 +1,199 @@ > +/* > + * Copyright (C) 2016 BayLibre SAS. > + * Author: Neil Armstrong <narmstrong@baylibre.com> > + * Heavily based on meson_mhu.c from : > + * Copyright (C) 2013-2015 Fujitsu Semiconductor Ltd. > + * Copyright (C) 2015 Linaro Ltd. > + * Author: Jassi Brar <jaswinder.singh@linaro.org> ......... > + > +#define INTR_SET_OFS 0x0 > +#define INTR_STAT_OFS 0x4 > +#define INTR_CLR_OFS 0x8 > + > +#define MHU_LP_OFFSET 0x10 > +#define MHU_HP_OFFSET 0x1c > + > +#define TX_REG_OFFSET 0x24 > + It seems only some register offsets have changed from arm_mhu. So maybe just adapt the arm_mhu driver to look for IP variant and assign corresponding offsets to set,stat,clr registers. Cheers.
On 06/22/2016 06:31 AM, Jassi Brar wrote: > On Tue, Jun 21, 2016 at 3:32 PM, Neil Armstrong <narmstrong@baylibre.com> wrote: >> Add Amlogic Meson SoCs Message-Handling-Unit as mailbox controller >> with 2 independent channels/links to communicate with a remote processor. >> >> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> > > ..... > >> +++ b/drivers/mailbox/meson_mhu.c >> @@ -0,0 +1,199 @@ >> +/* >> + * Copyright (C) 2016 BayLibre SAS. >> + * Author: Neil Armstrong <narmstrong@baylibre.com> >> + * Heavily based on meson_mhu.c from : >> + * Copyright (C) 2013-2015 Fujitsu Semiconductor Ltd. >> + * Copyright (C) 2015 Linaro Ltd. >> + * Author: Jassi Brar <jaswinder.singh@linaro.org> > > ......... >> + >> +#define INTR_SET_OFS 0x0 >> +#define INTR_STAT_OFS 0x4 >> +#define INTR_CLR_OFS 0x8 >> + >> +#define MHU_LP_OFFSET 0x10 >> +#define MHU_HP_OFFSET 0x1c >> + >> +#define TX_REG_OFFSET 0x24 >> + > It seems only some register offsets have changed from arm_mhu. So > maybe just adapt the arm_mhu driver to look for IP variant and assign > corresponding offsets to set,stat,clr registers. Hi Jassi, It's a good idea, but adding the platform_driver support along the amba_bus probe will add a lot a code. The meson_mhu is a very simple and short driver, I think it'll be simpler to maintain beeing separated. And I'm not certain on how it's close of ARM's real IP. Neil > Cheers. >
On Tue, Jun 21, 2016 at 3:32 PM, Neil Armstrong <narmstrong@baylibre.com> wrote: > Add Amlogic Meson SoCs Message-Handling-Unit as mailbox controller > with 2 independent channels/links to communicate with a remote processor. > > Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> > --- > drivers/mailbox/Makefile | 2 + > drivers/mailbox/meson_mhu.c | 199 ++++++++++++++++++++++++++++++++++++++++++++ > Can we call it pdev_mhu.c or similar so that some other platform using the MHU as a platform_device wouldn't have to embarrassingly call it 'Meson's MHU'? And also the replace meson with that prefix in the code. > 2 files changed, 201 insertions(+) > create mode 100644 drivers/mailbox/meson_mhu.c > > diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile > index 0be3e74..6aa9dbe 100644 > --- a/drivers/mailbox/Makefile > +++ b/drivers/mailbox/Makefile > @@ -25,3 +25,5 @@ obj-$(CONFIG_TI_MESSAGE_MANAGER) += ti-msgmgr.o > obj-$(CONFIG_XGENE_SLIMPRO_MBOX) += mailbox-xgene-slimpro.o > > obj-$(CONFIG_HI6220_MBOX) += hi6220-mailbox.o > + > +obj-$(CONFIG_ARCH_MESON) += meson_mhu.o > diff --git a/drivers/mailbox/meson_mhu.c b/drivers/mailbox/meson_mhu.c > new file mode 100644 > index 0000000..0576b92 > --- /dev/null > +++ b/drivers/mailbox/meson_mhu.c > @@ -0,0 +1,199 @@ > +/* > + * Copyright (C) 2016 BayLibre SAS. > + * Author: Neil Armstrong <narmstrong@baylibre.com> > + * Heavily based on meson_mhu.c from : > + * Copyright (C) 2013-2015 Fujitsu Semiconductor Ltd. > + * Copyright (C) 2015 Linaro Ltd. > + * Author: Jassi Brar <jaswinder.singh@linaro.org> > + * > + * This program is free software: you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation, version 2 of the License. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + */ > + > +#include <linux/interrupt.h> > +#include <linux/spinlock.h> > +#include <linux/mutex.h> > +#include <linux/delay.h> > +#include <linux/slab.h> > +#include <linux/err.h> > +#include <linux/io.h> > +#include <linux/module.h> > +#include <linux/platform_device.h> > +#include <linux/mailbox_controller.h> > + > +#define INTR_SET_OFS 0x0 > +#define INTR_STAT_OFS 0x4 > +#define INTR_CLR_OFS 0x8 > + > +#define MHU_LP_OFFSET 0x10 > +#define MHU_HP_OFFSET 0x1c > + > +#define TX_REG_OFFSET 0x24 > + > +#define MHU_CHANS 2 > + > +struct meson_mhu_link { > + unsigned int irq; > + void __iomem *tx_reg; > + void __iomem *rx_reg; > +}; > + > +struct meson_mhu { > + void __iomem *base; > + struct meson_mhu_link mlink[MHU_CHANS]; > + struct mbox_chan chan[MHU_CHANS]; > + struct mbox_controller mbox; > +}; > + > +static irqreturn_t meson_mhu_rx_interrupt(int irq, void *p) > +{ > + struct mbox_chan *chan = p; > + struct meson_mhu_link *mlink = chan->con_priv; > + u32 val; > + > + val = readl_relaxed(mlink->rx_reg + INTR_STAT_OFS); > + if (!val) > + return IRQ_NONE; > + > + mbox_chan_received_data(chan, (void *)&val); > + > + writel_relaxed(~0, mlink->rx_reg + INTR_CLR_OFS); > + How about sync with arm_mhu.c by doing writel_relaxed(val, mlink->rx_reg + INTR_CLR_OFS) ? > + return IRQ_HANDLED; > +} > + > +static bool meson_mhu_last_tx_done(struct mbox_chan *chan) > +{ > + struct meson_mhu_link *mlink = chan->con_priv; > + u32 val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS); > + > + return (val == 0); > +} > + > +static int meson_mhu_send_data(struct mbox_chan *chan, void *data) > +{ > + struct meson_mhu_link *mlink = chan->con_priv; > + u32 *arg = data; > + > + writel_relaxed(*arg, mlink->tx_reg + INTR_SET_OFS); > + > + return 0; > +} > + > +static int meson_mhu_startup(struct mbox_chan *chan) > +{ > + struct meson_mhu_link *mlink = chan->con_priv; > + int ret; > + arm_mhu.c clears any pending TX before taking over by doing ... val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS); writel_relaxed(val, mlink->tx_reg + INTR_CLR_OFS); > + ret = request_irq(mlink->irq, meson_mhu_rx_interrupt, > + IRQF_ONESHOT, "meson_mhu_link", chan); > + if (ret) { > + dev_err(chan->mbox->dev, > + "Unable to acquire IRQ %d\n", mlink->irq); > + return ret; > + } > + > + return 0; > +} > + > +static void meson_mhu_shutdown(struct mbox_chan *chan) > +{ > + struct meson_mhu_link *mlink = chan->con_priv; > + > + free_irq(mlink->irq, chan); > +} > + > +static const struct mbox_chan_ops meson_mhu_ops = { > + .send_data = meson_mhu_send_data, > + .startup = meson_mhu_startup, > + .shutdown = meson_mhu_shutdown, > + .last_tx_done = meson_mhu_last_tx_done, > +}; > My two comments above may not be necessary for your platform, but I would suggest we keep the core (from the declaration of struct meson_mhu_link to this point) in sync with arm_mhu.c > +static int meson_mhu_probe(struct platform_device *pdev) > +{ > + int i, err; > + struct meson_mhu *mhu; > + struct device *dev = &pdev->dev; > + struct resource *res; > + int meson_mhu_reg[MHU_CHANS] = {MHU_LP_OFFSET, MHU_HP_OFFSET}; > + > + /* Allocate memory for device */ > + mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL); > + if (!mhu) > + return -ENOMEM; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + mhu->base = devm_ioremap_resource(dev, res); > + if (IS_ERR(mhu->base)) { > + dev_err(dev, "ioremap failed\n"); > + return PTR_ERR(mhu->base); > + } > + > + for (i = 0; i < MHU_CHANS; i++) { > + mhu->chan[i].con_priv = &mhu->mlink[i]; > + mhu->mlink[i].irq = platform_get_irq(pdev, i); > + if (mhu->mlink[i].irq < 0) { > + dev_err(dev, "failed to get irq%d\n", i); > + return mhu->mlink[i].irq; > + } > + mhu->mlink[i].rx_reg = mhu->base + meson_mhu_reg[i]; > + mhu->mlink[i].tx_reg = mhu->mlink[i].rx_reg + TX_REG_OFFSET; > + } > + > + mhu->mbox.dev = dev; > + mhu->mbox.chans = &mhu->chan[0]; > + mhu->mbox.num_chans = MHU_CHANS; > + mhu->mbox.ops = &meson_mhu_ops; > + mhu->mbox.txdone_irq = false; > + mhu->mbox.txdone_poll = true; > + mhu->mbox.txpoll_period = 1; > + > + platform_set_drvdata(pdev, mhu); > + > + err = mbox_controller_register(&mhu->mbox); > + if (err) { > + dev_err(dev, "Failed to register mailboxes %d\n", err); > + return err; > + } > + > + dev_info(dev, "Meson MHU Mailbox registered\n"); > + return 0; > +} > + > +static int meson_mhu_remove(struct platform_device *pdev) > +{ > + struct meson_mhu *mhu = platform_get_drvdata(pdev); > + > + mbox_controller_unregister(&mhu->mbox); > + > + return 0; > +} > + > +static const struct of_device_id meson_mhu_dt_ids[] = { > + { .compatible = "amlogic,meson-gxbb-mhu", }, > + { /* sentinel */ }, > +}; > +MODULE_DEVICE_TABLE(of, meson_mhu_ids); > + > +static struct platform_driver meson_wdt_driver = { > + .probe = meson_mhu_probe, > + .remove = meson_mhu_remove, > + .driver = { > + .name = "meson-mhu", > + .of_match_table = meson_mhu_dt_ids, > + }, > +}; > + > +module_platform_driver(meson_wdt_driver); > + wdt as in watchdog-timer from drivers/watchdog/meson_wdt.c ? :) Thanks.
2016-07-04 17:38 GMT+02:00 Jassi Brar <jassisinghbrar@gmail.com>: > On Tue, Jun 21, 2016 at 3:32 PM, Neil Armstrong <narmstrong@baylibre.com> wrote: >> Add Amlogic Meson SoCs Message-Handling-Unit as mailbox controller >> with 2 independent channels/links to communicate with a remote processor. >> >> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> >> --- >> drivers/mailbox/Makefile | 2 + >> drivers/mailbox/meson_mhu.c | 199 ++++++++++++++++++++++++++++++++++++++++++++ >> > Can we call it pdev_mhu.c or similar so that some other platform using > the MHU as a platform_device wouldn't have to embarrassingly call it > 'Meson's MHU'? And also the replace meson with that prefix in the > code. Yes, it may deserve a more generic naming, but pdev_mhu is not good looking at all ! What about platform_mhu ? > >> 2 files changed, 201 insertions(+) >> create mode 100644 drivers/mailbox/meson_mhu.c >> >> diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile >> index 0be3e74..6aa9dbe 100644 >> --- a/drivers/mailbox/Makefile >> +++ b/drivers/mailbox/Makefile >> @@ -25,3 +25,5 @@ obj-$(CONFIG_TI_MESSAGE_MANAGER) += ti-msgmgr.o >> obj-$(CONFIG_XGENE_SLIMPRO_MBOX) += mailbox-xgene-slimpro.o >> >> obj-$(CONFIG_HI6220_MBOX) += hi6220-mailbox.o >> + >> +obj-$(CONFIG_ARCH_MESON) += meson_mhu.o >> diff --git a/drivers/mailbox/meson_mhu.c b/drivers/mailbox/meson_mhu.c >> new file mode 100644 >> index 0000000..0576b92 >> --- /dev/null >> +++ b/drivers/mailbox/meson_mhu.c >> @@ -0,0 +1,199 @@ >> +/* >> + * Copyright (C) 2016 BayLibre SAS. >> + * Author: Neil Armstrong <narmstrong@baylibre.com> >> + * Heavily based on meson_mhu.c from : >> + * Copyright (C) 2013-2015 Fujitsu Semiconductor Ltd. >> + * Copyright (C) 2015 Linaro Ltd. >> + * Author: Jassi Brar <jaswinder.singh@linaro.org> >> + * >> + * This program is free software: you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License as published by >> + * the Free Software Foundation, version 2 of the License. >> + * >> + * This program is distributed in the hope that it will be useful, >> + * but WITHOUT ANY WARRANTY; without even the implied warranty of >> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the >> + * GNU General Public License for more details. >> + */ >> + >> +#include <linux/interrupt.h> >> +#include <linux/spinlock.h> >> +#include <linux/mutex.h> >> +#include <linux/delay.h> >> +#include <linux/slab.h> >> +#include <linux/err.h> >> +#include <linux/io.h> >> +#include <linux/module.h> >> +#include <linux/platform_device.h> >> +#include <linux/mailbox_controller.h> >> + >> +#define INTR_SET_OFS 0x0 >> +#define INTR_STAT_OFS 0x4 >> +#define INTR_CLR_OFS 0x8 >> + >> +#define MHU_LP_OFFSET 0x10 >> +#define MHU_HP_OFFSET 0x1c >> + >> +#define TX_REG_OFFSET 0x24 >> + >> +#define MHU_CHANS 2 >> + >> +struct meson_mhu_link { >> + unsigned int irq; >> + void __iomem *tx_reg; >> + void __iomem *rx_reg; >> +}; >> + >> +struct meson_mhu { >> + void __iomem *base; >> + struct meson_mhu_link mlink[MHU_CHANS]; >> + struct mbox_chan chan[MHU_CHANS]; >> + struct mbox_controller mbox; >> +}; >> + >> +static irqreturn_t meson_mhu_rx_interrupt(int irq, void *p) >> +{ >> + struct mbox_chan *chan = p; >> + struct meson_mhu_link *mlink = chan->con_priv; >> + u32 val; >> + >> + val = readl_relaxed(mlink->rx_reg + INTR_STAT_OFS); >> + if (!val) >> + return IRQ_NONE; >> + >> + mbox_chan_received_data(chan, (void *)&val); >> + >> + writel_relaxed(~0, mlink->rx_reg + INTR_CLR_OFS); >> + > How about sync with arm_mhu.c by doing writel_relaxed(val, > mlink->rx_reg + INTR_CLR_OFS) ? The ~0 was taken from the vendor driver, but writing val should work, I must test this change. > >> + return IRQ_HANDLED; >> +} >> + >> +static bool meson_mhu_last_tx_done(struct mbox_chan *chan) >> +{ >> + struct meson_mhu_link *mlink = chan->con_priv; >> + u32 val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS); >> + >> + return (val == 0); >> +} >> + >> +static int meson_mhu_send_data(struct mbox_chan *chan, void *data) >> +{ >> + struct meson_mhu_link *mlink = chan->con_priv; >> + u32 *arg = data; >> + >> + writel_relaxed(*arg, mlink->tx_reg + INTR_SET_OFS); >> + >> + return 0; >> +} >> + >> +static int meson_mhu_startup(struct mbox_chan *chan) >> +{ >> + struct meson_mhu_link *mlink = chan->con_priv; >> + int ret; >> + > arm_mhu.c clears any pending TX before taking over by doing ... > val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS); > writel_relaxed(val, mlink->tx_reg + INTR_CLR_OFS); I dropped it not knowing it it was necessary because not pressent in the vendor code, but yes it would clearly be good to get it back. >> + ret = request_irq(mlink->irq, meson_mhu_rx_interrupt, >> + IRQF_ONESHOT, "meson_mhu_link", chan); >> + if (ret) { >> + dev_err(chan->mbox->dev, >> + "Unable to acquire IRQ %d\n", mlink->irq); >> + return ret; >> + } >> + >> + return 0; >> +} >> + >> +static void meson_mhu_shutdown(struct mbox_chan *chan) >> +{ >> + struct meson_mhu_link *mlink = chan->con_priv; >> + >> + free_irq(mlink->irq, chan); >> +} >> + >> +static const struct mbox_chan_ops meson_mhu_ops = { >> + .send_data = meson_mhu_send_data, >> + .startup = meson_mhu_startup, >> + .shutdown = meson_mhu_shutdown, >> + .last_tx_done = meson_mhu_last_tx_done, >> +}; >> > My two comments above may not be necessary for your platform, but I > would suggest we keep the core (from the declaration of struct > meson_mhu_link to this point) in sync with arm_mhu.c Yes, I'll keep them as synced as possible. >> +static int meson_mhu_probe(struct platform_device *pdev) >> +{ >> + int i, err; >> + struct meson_mhu *mhu; >> + struct device *dev = &pdev->dev; >> + struct resource *res; >> + int meson_mhu_reg[MHU_CHANS] = {MHU_LP_OFFSET, MHU_HP_OFFSET}; >> + >> + /* Allocate memory for device */ >> + mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL); >> + if (!mhu) >> + return -ENOMEM; >> + >> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); >> + mhu->base = devm_ioremap_resource(dev, res); >> + if (IS_ERR(mhu->base)) { >> + dev_err(dev, "ioremap failed\n"); >> + return PTR_ERR(mhu->base); >> + } >> + >> + for (i = 0; i < MHU_CHANS; i++) { >> + mhu->chan[i].con_priv = &mhu->mlink[i]; >> + mhu->mlink[i].irq = platform_get_irq(pdev, i); >> + if (mhu->mlink[i].irq < 0) { >> + dev_err(dev, "failed to get irq%d\n", i); >> + return mhu->mlink[i].irq; >> + } >> + mhu->mlink[i].rx_reg = mhu->base + meson_mhu_reg[i]; >> + mhu->mlink[i].tx_reg = mhu->mlink[i].rx_reg + TX_REG_OFFSET; >> + } >> + >> + mhu->mbox.dev = dev; >> + mhu->mbox.chans = &mhu->chan[0]; >> + mhu->mbox.num_chans = MHU_CHANS; >> + mhu->mbox.ops = &meson_mhu_ops; >> + mhu->mbox.txdone_irq = false; >> + mhu->mbox.txdone_poll = true; >> + mhu->mbox.txpoll_period = 1; >> + >> + platform_set_drvdata(pdev, mhu); >> + >> + err = mbox_controller_register(&mhu->mbox); >> + if (err) { >> + dev_err(dev, "Failed to register mailboxes %d\n", err); >> + return err; >> + } >> + >> + dev_info(dev, "Meson MHU Mailbox registered\n"); >> + return 0; >> +} >> + >> +static int meson_mhu_remove(struct platform_device *pdev) >> +{ >> + struct meson_mhu *mhu = platform_get_drvdata(pdev); >> + >> + mbox_controller_unregister(&mhu->mbox); >> + >> + return 0; >> +} >> + >> +static const struct of_device_id meson_mhu_dt_ids[] = { >> + { .compatible = "amlogic,meson-gxbb-mhu", }, >> + { /* sentinel */ }, >> +}; >> +MODULE_DEVICE_TABLE(of, meson_mhu_ids); >> + >> +static struct platform_driver meson_wdt_driver = { >> + .probe = meson_mhu_probe, >> + .remove = meson_mhu_remove, >> + .driver = { >> + .name = "meson-mhu", >> + .of_match_table = meson_mhu_dt_ids, >> + }, >> +}; >> + >> +module_platform_driver(meson_wdt_driver); >> + > wdt as in watchdog-timer from drivers/watchdog/meson_wdt.c ? :) Sorry, it was a leftover from another pdev driver, but the freshly pushed meson_gxbb_wdt ! > Thanks. Thanks for the feedback, Neil
On Wed, Jul 6, 2016 at 6:47 PM, Neil Armstrong <narmstrong@baylibre.com> wrote: > 2016-07-04 17:38 GMT+02:00 Jassi Brar <jassisinghbrar@gmail.com>: >> On Tue, Jun 21, 2016 at 3:32 PM, Neil Armstrong <narmstrong@baylibre.com> wrote: >>> Add Amlogic Meson SoCs Message-Handling-Unit as mailbox controller >>> with 2 independent channels/links to communicate with a remote processor. >>> >>> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> >>> --- >>> drivers/mailbox/Makefile | 2 + >>> drivers/mailbox/meson_mhu.c | 199 ++++++++++++++++++++++++++++++++++++++++++++ >>> >> Can we call it pdev_mhu.c or similar so that some other platform using >> the MHU as a platform_device wouldn't have to embarrassingly call it >> 'Meson's MHU'? And also the replace meson with that prefix in the >> code. > > Yes, it may deserve a more generic naming, but pdev_mhu is not good > looking at all ! > What about platform_mhu ? > OK
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile index 0be3e74..6aa9dbe 100644 --- a/drivers/mailbox/Makefile +++ b/drivers/mailbox/Makefile @@ -25,3 +25,5 @@ obj-$(CONFIG_TI_MESSAGE_MANAGER) += ti-msgmgr.o obj-$(CONFIG_XGENE_SLIMPRO_MBOX) += mailbox-xgene-slimpro.o obj-$(CONFIG_HI6220_MBOX) += hi6220-mailbox.o + +obj-$(CONFIG_ARCH_MESON) += meson_mhu.o diff --git a/drivers/mailbox/meson_mhu.c b/drivers/mailbox/meson_mhu.c new file mode 100644 index 0000000..0576b92 --- /dev/null +++ b/drivers/mailbox/meson_mhu.c @@ -0,0 +1,199 @@ +/* + * Copyright (C) 2016 BayLibre SAS. + * Author: Neil Armstrong <narmstrong@baylibre.com> + * Heavily based on meson_mhu.c from : + * Copyright (C) 2013-2015 Fujitsu Semiconductor Ltd. + * Copyright (C) 2015 Linaro Ltd. + * Author: Jassi Brar <jaswinder.singh@linaro.org> + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/interrupt.h> +#include <linux/spinlock.h> +#include <linux/mutex.h> +#include <linux/delay.h> +#include <linux/slab.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/mailbox_controller.h> + +#define INTR_SET_OFS 0x0 +#define INTR_STAT_OFS 0x4 +#define INTR_CLR_OFS 0x8 + +#define MHU_LP_OFFSET 0x10 +#define MHU_HP_OFFSET 0x1c + +#define TX_REG_OFFSET 0x24 + +#define MHU_CHANS 2 + +struct meson_mhu_link { + unsigned int irq; + void __iomem *tx_reg; + void __iomem *rx_reg; +}; + +struct meson_mhu { + void __iomem *base; + struct meson_mhu_link mlink[MHU_CHANS]; + struct mbox_chan chan[MHU_CHANS]; + struct mbox_controller mbox; +}; + +static irqreturn_t meson_mhu_rx_interrupt(int irq, void *p) +{ + struct mbox_chan *chan = p; + struct meson_mhu_link *mlink = chan->con_priv; + u32 val; + + val = readl_relaxed(mlink->rx_reg + INTR_STAT_OFS); + if (!val) + return IRQ_NONE; + + mbox_chan_received_data(chan, (void *)&val); + + writel_relaxed(~0, mlink->rx_reg + INTR_CLR_OFS); + + return IRQ_HANDLED; +} + +static bool meson_mhu_last_tx_done(struct mbox_chan *chan) +{ + struct meson_mhu_link *mlink = chan->con_priv; + u32 val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS); + + return (val == 0); +} + +static int meson_mhu_send_data(struct mbox_chan *chan, void *data) +{ + struct meson_mhu_link *mlink = chan->con_priv; + u32 *arg = data; + + writel_relaxed(*arg, mlink->tx_reg + INTR_SET_OFS); + + return 0; +} + +static int meson_mhu_startup(struct mbox_chan *chan) +{ + struct meson_mhu_link *mlink = chan->con_priv; + int ret; + + ret = request_irq(mlink->irq, meson_mhu_rx_interrupt, + IRQF_ONESHOT, "meson_mhu_link", chan); + if (ret) { + dev_err(chan->mbox->dev, + "Unable to acquire IRQ %d\n", mlink->irq); + return ret; + } + + return 0; +} + +static void meson_mhu_shutdown(struct mbox_chan *chan) +{ + struct meson_mhu_link *mlink = chan->con_priv; + + free_irq(mlink->irq, chan); +} + +static const struct mbox_chan_ops meson_mhu_ops = { + .send_data = meson_mhu_send_data, + .startup = meson_mhu_startup, + .shutdown = meson_mhu_shutdown, + .last_tx_done = meson_mhu_last_tx_done, +}; + +static int meson_mhu_probe(struct platform_device *pdev) +{ + int i, err; + struct meson_mhu *mhu; + struct device *dev = &pdev->dev; + struct resource *res; + int meson_mhu_reg[MHU_CHANS] = {MHU_LP_OFFSET, MHU_HP_OFFSET}; + + /* Allocate memory for device */ + mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL); + if (!mhu) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + mhu->base = devm_ioremap_resource(dev, res); + if (IS_ERR(mhu->base)) { + dev_err(dev, "ioremap failed\n"); + return PTR_ERR(mhu->base); + } + + for (i = 0; i < MHU_CHANS; i++) { + mhu->chan[i].con_priv = &mhu->mlink[i]; + mhu->mlink[i].irq = platform_get_irq(pdev, i); + if (mhu->mlink[i].irq < 0) { + dev_err(dev, "failed to get irq%d\n", i); + return mhu->mlink[i].irq; + } + mhu->mlink[i].rx_reg = mhu->base + meson_mhu_reg[i]; + mhu->mlink[i].tx_reg = mhu->mlink[i].rx_reg + TX_REG_OFFSET; + } + + mhu->mbox.dev = dev; + mhu->mbox.chans = &mhu->chan[0]; + mhu->mbox.num_chans = MHU_CHANS; + mhu->mbox.ops = &meson_mhu_ops; + mhu->mbox.txdone_irq = false; + mhu->mbox.txdone_poll = true; + mhu->mbox.txpoll_period = 1; + + platform_set_drvdata(pdev, mhu); + + err = mbox_controller_register(&mhu->mbox); + if (err) { + dev_err(dev, "Failed to register mailboxes %d\n", err); + return err; + } + + dev_info(dev, "Meson MHU Mailbox registered\n"); + return 0; +} + +static int meson_mhu_remove(struct platform_device *pdev) +{ + struct meson_mhu *mhu = platform_get_drvdata(pdev); + + mbox_controller_unregister(&mhu->mbox); + + return 0; +} + +static const struct of_device_id meson_mhu_dt_ids[] = { + { .compatible = "amlogic,meson-gxbb-mhu", }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, meson_mhu_ids); + +static struct platform_driver meson_wdt_driver = { + .probe = meson_mhu_probe, + .remove = meson_mhu_remove, + .driver = { + .name = "meson-mhu", + .of_match_table = meson_mhu_dt_ids, + }, +}; + +module_platform_driver(meson_wdt_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:meson-mhu"); +MODULE_DESCRIPTION("Amlogic Meson MHU Driver"); +MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
Add Amlogic Meson SoCs Message-Handling-Unit as mailbox controller with 2 independent channels/links to communicate with a remote processor. Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> --- drivers/mailbox/Makefile | 2 + drivers/mailbox/meson_mhu.c | 199 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 201 insertions(+) create mode 100644 drivers/mailbox/meson_mhu.c