Re: [RFC PATCH v2 1/9] mailbox: Add Amlogic Meson Message-Handling-Unit

From: Neil Armstrong
Date: Thu Jun 23 2016 - 11:46:55 EST


On 06/22/2016 06:31 AM, Jassi Brar wrote:
> On Tue, Jun 21, 2016 at 3:32 PM, Neil Armstrong <narmstrong@xxxxxxxxxxxx> 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@xxxxxxxxxxxx>
>
> .....
>
>> +++ b/drivers/mailbox/meson_mhu.c
>> @@ -0,0 +1,199 @@
>> +/*
>> + * Copyright (C) 2016 BayLibre SAS.
>> + * Author: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
>> + * Heavily based on meson_mhu.c from :
>> + * Copyright (C) 2013-2015 Fujitsu Semiconductor Ltd.
>> + * Copyright (C) 2015 Linaro Ltd.
>> + * Author: Jassi Brar <jaswinder.singh@xxxxxxxxxx>
>
> .........
>> +
>> +#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.
>

Hi Jassi,

I did a quick & dirty merge with arm_mhu, and I don't it's a good idea...

Please have a look at attached patch.

Regards,
Neil
-------------------------------------------------------------------------------------------
From: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
Subject: [PATCH] mailbox: arm_mhu: Add support for Amlogic Meson MHU

To achieve this integration, add support for generic probe from amba
or platform.
Move all register offsets to a data structure passed in either amba id or
platform dt id match table.

Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
---
drivers/mailbox/arm_mhu.c | 217 ++++++++++++++++++++++++++++++++++++++--------
1 file changed, 181 insertions(+), 36 deletions(-)

diff --git a/drivers/mailbox/arm_mhu.c b/drivers/mailbox/arm_mhu.c
index 99befa7..d7fb843 100644
--- a/drivers/mailbox/arm_mhu.c
+++ b/drivers/mailbox/arm_mhu.c
@@ -22,45 +22,68 @@
#include <linux/io.h>
#include <linux/module.h>
#include <linux/amba/bus.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
#include <linux/mailbox_controller.h>

-#define INTR_STAT_OFS 0x0
-#define INTR_SET_OFS 0x8
-#define INTR_CLR_OFS 0x10
+#define MHU_INTR_STAT_OFS 0x0
+#define MHU_INTR_SET_OFS 0x8
+#define MHU_INTR_CLR_OFS 0x10

#define MHU_LP_OFFSET 0x0
#define MHU_HP_OFFSET 0x20
#define MHU_SEC_OFFSET 0x200
-#define TX_REG_OFFSET 0x100
+#define MHU_TX_REG_OFFSET 0x100

-#define MHU_CHANS 3
+#define MESON_INTR_SET_OFS 0x0
+#define MESON_INTR_STAT_OFS 0x4
+#define MESON_INTR_CLR_OFS 0x8
+
+#define MESON_MHU_LP_OFFSET 0x10
+#define MESON_MHU_HP_OFFSET 0x1c
+#define MESON_MHU_TX_OFFSET 0x24
+
+#define MAX_MHU_CHANS 3

struct mhu_link {
unsigned irq;
- void __iomem *tx_reg;
- void __iomem *rx_reg;
+ void __iomem *tx_stat_reg;
+ void __iomem *tx_set_reg;
+ void __iomem *tx_clr_reg;
+ void __iomem *rx_stat_reg;
+ void __iomem *rx_set_reg;
+ void __iomem *rx_clr_reg;
};

struct arm_mhu {
void __iomem *base;
- struct mhu_link mlink[MHU_CHANS];
- struct mbox_chan chan[MHU_CHANS];
+ struct mhu_link mlink[MAX_MHU_CHANS];
+ struct mbox_chan chan[MAX_MHU_CHANS];
struct mbox_controller mbox;
};

+struct arm_mhu_data {
+ unsigned int channels;
+ int rx_offsets[MAX_MHU_CHANS];
+ int tx_offsets[MAX_MHU_CHANS];
+ unsigned int intr_stat_offs;
+ unsigned int intr_set_offs;
+ unsigned int intr_clr_offs;
+};
+
static irqreturn_t mhu_rx_interrupt(int irq, void *p)
{
struct mbox_chan *chan = p;
struct mhu_link *mlink = chan->con_priv;
u32 val;

- val = readl_relaxed(mlink->rx_reg + INTR_STAT_OFS);
+ val = readl_relaxed(mlink->rx_stat_reg);
if (!val)
return IRQ_NONE;

mbox_chan_received_data(chan, (void *)&val);

- writel_relaxed(val, mlink->rx_reg + INTR_CLR_OFS);
+ writel_relaxed(val, mlink->rx_clr_reg);

return IRQ_HANDLED;
}
@@ -68,7 +91,7 @@ static irqreturn_t mhu_rx_interrupt(int irq, void *p)
static bool mhu_last_tx_done(struct mbox_chan *chan)
{
struct mhu_link *mlink = chan->con_priv;
- u32 val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS);
+ u32 val = readl_relaxed(mlink->tx_stat_reg);

return (val == 0);
}
@@ -78,7 +101,7 @@ static int mhu_send_data(struct mbox_chan *chan, void *data)
struct mhu_link *mlink = chan->con_priv;
u32 *arg = data;

- writel_relaxed(*arg, mlink->tx_reg + INTR_SET_OFS);
+ writel_relaxed(*arg, mlink->tx_set_reg);

return 0;
}
@@ -89,8 +112,8 @@ static int mhu_startup(struct mbox_chan *chan)
u32 val;
int ret;

- val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS);
- writel_relaxed(val, mlink->tx_reg + INTR_CLR_OFS);
+ val = readl_relaxed(mlink->tx_stat_reg);
+ writel_relaxed(val, mlink->tx_clr_reg);

ret = request_irq(mlink->irq, mhu_rx_interrupt,
IRQF_SHARED, "mhu_link", chan);
@@ -117,52 +140,155 @@ static const struct mbox_chan_ops mhu_ops = {
.last_tx_done = mhu_last_tx_done,
};

-static int mhu_probe(struct amba_device *adev, const struct amba_id *id)
+static struct arm_mhu_data arm_mhu_amba_data = {
+ .channels = 3,
+ .rx_offsets = {MHU_LP_OFFSET, MHU_HP_OFFSET, MHU_SEC_OFFSET},
+ .tx_offsets = {MHU_LP_OFFSET + MHU_TX_REG_OFFSET,
+ MHU_HP_OFFSET + MHU_TX_REG_OFFSET,
+ MHU_SEC_OFFSET + MHU_TX_REG_OFFSET},
+ .intr_stat_offs = MHU_INTR_STAT_OFS,
+ .intr_set_offs = MHU_INTR_SET_OFS,
+ .intr_clr_offs = MHU_INTR_CLR_OFS,
+};
+
+static const struct arm_mhu_data meson_mhu_data = {
+ .channels = 2,
+ .rx_offsets = {MESON_MHU_LP_OFFSET, MESON_MHU_HP_OFFSET},
+ .tx_offsets = {MESON_MHU_LP_OFFSET + MESON_MHU_TX_OFFSET,
+ MESON_MHU_HP_OFFSET + MESON_MHU_TX_OFFSET},
+ .intr_stat_offs = MESON_INTR_STAT_OFS,
+ .intr_set_offs = MESON_INTR_SET_OFS,
+ .intr_clr_offs = MESON_INTR_CLR_OFS,
+};
+
+static struct arm_mhu *mhu_generic_probe(struct device *dev,
+ struct resource *res,
+ unsigned int irqs[],
+ const struct arm_mhu_data *data)
{
int i, err;
struct arm_mhu *mhu;
- struct device *dev = &adev->dev;
- int mhu_reg[MHU_CHANS] = {MHU_LP_OFFSET, MHU_HP_OFFSET, MHU_SEC_OFFSET};

/* Allocate memory for device */
mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL);
if (!mhu)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);

- mhu->base = devm_ioremap_resource(dev, &adev->res);
+ mhu->base = devm_ioremap_resource(dev, res);
if (IS_ERR(mhu->base)) {
dev_err(dev, "ioremap failed\n");
- return PTR_ERR(mhu->base);
+ return ERR_CAST(mhu->base);
}

- for (i = 0; i < MHU_CHANS; i++) {
+ for (i = 0; i < data->channels; i++) {
+ void __iomem *reg_base;
mhu->chan[i].con_priv = &mhu->mlink[i];
- mhu->mlink[i].irq = adev->irq[i];
- mhu->mlink[i].rx_reg = mhu->base + mhu_reg[i];
- mhu->mlink[i].tx_reg = mhu->mlink[i].rx_reg + TX_REG_OFFSET;
+ mhu->mlink[i].irq = irqs[i];
+ reg_base = mhu->base + data->rx_offsets[i];
+ mhu->mlink[i].rx_stat_reg = reg_base + data->intr_stat_offs;
+ mhu->mlink[i].rx_set_reg = reg_base + data->intr_set_offs;
+ mhu->mlink[i].rx_clr_reg = reg_base + data->intr_clr_offs;
+ reg_base = mhu->base + data->tx_offsets[i];
+ mhu->mlink[i].rx_stat_reg = reg_base + data->intr_stat_offs;
+ mhu->mlink[i].rx_set_reg = reg_base + data->intr_set_offs;
+ mhu->mlink[i].rx_clr_reg = reg_base + data->intr_clr_offs;
}

mhu->mbox.dev = dev;
mhu->mbox.chans = &mhu->chan[0];
- mhu->mbox.num_chans = MHU_CHANS;
+ mhu->mbox.num_chans = data->channels;
mhu->mbox.ops = &mhu_ops;
mhu->mbox.txdone_irq = false;
mhu->mbox.txdone_poll = true;
mhu->mbox.txpoll_period = 1;

- amba_set_drvdata(adev, mhu);
-
err = mbox_controller_register(&mhu->mbox);
if (err) {
dev_err(dev, "Failed to register mailboxes %d\n", err);
- return err;
+ return ERR_PTR(err);
}

dev_info(dev, "ARM MHU Mailbox registered\n");
return 0;
+};
+
+static const struct of_device_id mhu_dt_ids[] = {
+ { .compatible = "amlogic,meson-gxbb-mhu", .data = &meson_mhu_data},
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, mhu_dt_ids);
+
+static int mhu_platform_probe(struct platform_device *pdev)
+{
+ const struct of_device_id *match;
+ unsigned int irqs[MAX_MHU_CHANS];
+ const struct arm_mhu_data *data;
+ struct device *dev = &pdev->dev;
+ struct resource *res;
+ struct arm_mhu *mhu;
+ int i;
+
+ match = of_match_device(mhu_dt_ids, &pdev->dev);
+ if (!match)
+ return -EINVAL;
+
+ data = match->data;
+ if (!data)
+ return -EINVAL;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (WARN_ON(!res))
+ return -EINVAL;
+
+ for (i = 0 ; i < data->channels ; ++i) {
+ irqs[i] = platform_get_irq(pdev, i);
+ if (WARN_ON(irqs[i] < 0))
+ return irqs[i];
+ }
+
+ mhu = mhu_generic_probe(dev, res, irqs, data);
+ if (IS_ERR(mhu))
+ return PTR_ERR(mhu);
+
+ platform_set_drvdata(pdev, mhu);
+
+ return 0;
+}
+
+static int mhu_platform_remove(struct platform_device *pdev)
+{
+ struct arm_mhu *mhu = platform_get_drvdata(pdev);
+
+ mbox_controller_unregister(&mhu->mbox);
+
+ return 0;
+}
+
+static struct platform_driver mhu_platform_driver = {
+ .probe = mhu_platform_probe,
+ .remove = mhu_platform_remove,
+ .driver = {
+ .name = "meson-mhu",
+ .of_match_table = mhu_dt_ids,
+ },
+};
+
+static int mhu_amba_probe(struct amba_device *adev, const struct amba_id *id)
+{
+ const struct arm_mhu_data *data = id->data;
+ struct device *dev = &adev->dev;
+ struct arm_mhu *mhu;
+
+ mhu = mhu_generic_probe(dev, &adev->res, adev->irq, data);
+ if (IS_ERR(mhu))
+ return PTR_ERR(mhu);
+
+ amba_set_drvdata(adev, mhu);
+
+ return 0;
}

-static int mhu_remove(struct amba_device *adev)
+static int mhu_amba_remove(struct amba_device *adev)
{
struct arm_mhu *mhu = amba_get_drvdata(adev);

@@ -171,24 +297,43 @@ static int mhu_remove(struct amba_device *adev)
return 0;
}

-static struct amba_id mhu_ids[] = {
+static struct amba_id mhu_amba_ids[] = {
{
.id = 0x1bb098,
.mask = 0xffffff,
+ .data = &arm_mhu_amba_data,
},
{ 0, 0 },
};
-MODULE_DEVICE_TABLE(amba, mhu_ids);
+MODULE_DEVICE_TABLE(amba, mhu_amba_ids);

static struct amba_driver arm_mhu_driver = {
.drv = {
.name = "mhu",
},
- .id_table = mhu_ids,
- .probe = mhu_probe,
- .remove = mhu_remove,
+ .id_table = mhu_amba_ids,
+ .probe = mhu_amba_probe,
+ .remove = mhu_amba_remove,
};
-module_amba_driver(arm_mhu_driver);
+
+static int __init mhu_module_init(void)
+{
+ int ret;
+
+ ret = platform_driver_register(&mhu_platform_driver);
+ if (ret)
+ return ret;
+
+ return amba_driver_register(&arm_mhu_driver);
+}
+module_init(mhu_module_init);
+
+static void __exit mhu_module_exit(void)
+{
+ platform_driver_unregister(&mhu_platform_driver);
+ amba_driver_unregister(&arm_mhu_driver);
+}
+module_exit(mhu_module_exit);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("ARM MHU Driver");
--
2.7.0