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    SubjectRe: [PATCH 1/2] mailbox: samsung: added support for samsung mailbox
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    On Mon, Mar 17, 2014 at 5:33 PM, Girish K S <ks.giri@samsung.com> wrote:
    > This patch adds support to the samsung mailbox driver.
    >
    > Signed-off-by: Girish K S <ks.giri@samsung.com>
    > ---
    > drivers/mailbox/Kconfig | 8 +
    > drivers/mailbox/Makefile | 2 +
    > drivers/mailbox/mailbox-samsung.c | 354 +++++++++++++++++++++++++++++++++++++
    > include/linux/mailbox-samsung.h | 112 ++++++++++++
    > 4 files changed, 476 insertions(+)
    > create mode 100644 drivers/mailbox/mailbox-samsung.c
    > create mode 100644 include/linux/mailbox-samsung.h
    >
    > diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
    > index c8b5c13..bce60ba 100644
    > --- a/drivers/mailbox/Kconfig
    > +++ b/drivers/mailbox/Kconfig
    > @@ -23,6 +23,14 @@ config OMAP_MBOX
    > driver such as CONFIG_OMAP1_MBOX or CONFIG_OMAP2PLUS_MBOX. This
    > enables the common OMAP mailbox framework code.
    >
    > +config SAMSUNG_MBOX
    > + tristate "Samsung Mailbox Controller"
    > + help
    > + An implementation of the Samsung Interprocessor Communication
    > + Mailbox (IPCM). It is used to send short messages between A57 cores
    > + and the System Control Processor or Network Coprocessor firmware.
    > + Say Y here if you want to use the Samsung IPCM support.
    > +
    > config OMAP1_MBOX
    > tristate "OMAP1 Mailbox framework support"
    > depends on ARCH_OMAP1
    > diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
    > index 2fa343a..7e83a7d 100644
    > --- a/drivers/mailbox/Makefile
    > +++ b/drivers/mailbox/Makefile
    > @@ -9,3 +9,5 @@ obj-$(CONFIG_OMAP1_MBOX) += mailbox_omap1.o
    > mailbox_omap1-objs := mailbox-omap1.o
    > obj-$(CONFIG_OMAP2PLUS_MBOX) += mailbox_omap2.o
    > mailbox_omap2-objs := mailbox-omap2.o
    > +obj-$(CONFIG_SAMSUNG_MBOX) += mailbox_samsung.o
    > +mailbox_samsung-objs := mailbox-samsung.o
    > diff --git a/drivers/mailbox/mailbox-samsung.c b/drivers/mailbox/mailbox-samsung.c
    > new file mode 100644
    > index 0000000..903e88a
    > --- /dev/null
    > +++ b/drivers/mailbox/mailbox-samsung.c
    > @@ -0,0 +1,354 @@
    > +/*
    > + * Copyright 2013 Samsung Electronics Co. Ltd.
    > + *
    > + * This program is free software; you can redistribute it and/or modify it
    > + * under the terms and conditions of the GNU General Public License,
    > + * version 2, as published by the Free Software Foundation.
    > + *
    > + * This program is distributed in the hope 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.
    > + *
    > + * You should have received a copy of the GNU General Public License along with
    > + * this program. If not, see <http://www.gnu.org/licenses/>.
    > + */
    > +#include <linux/err.h>
    > +#include <linux/module.h>
    > +#include <linux/slab.h>
    > +#include <linux/interrupt.h>
    > +#include <linux/io.h>
    > +#include <linux/jiffies.h>
    > +#include <linux/mailbox_controller.h>
    > +#include <linux/mailbox-samsung.h>
    > +#include <linux/mutex.h>
    > +#include <linux/of.h>
    > +#include <linux/of_address.h>
    > +#include <linux/of_irq.h>
    > +#include <linux/platform_device.h>
    > +
    > +/*
    > + Mailbox Register offsets
    > + */
    > +
    > +/* Offset of tx mailbox data registers */
    > +#define MBOX_REG_RXDATA0 0
    > +#define MBOX_REG_RXDATA1 4
    > +
    > +/* offset of tx mailbox lock registers */
    > +#define MBOX_REG_RXLOCK 8
    > +#define MBOX_REG_RXUNLOCK 12
    > +
    > +/* offset of tx mailbox interrupt registers */
    > +#define MBOX_REG_RXINT 16
    > +
    > +/* Offset of rx mailbox data registers */
    > +#define MBOX_REG_TXDATA0 32
    > +#define MBOX_REG_TXDATA1 36
    > +
    > +/* offset of rx mailbox lock registers */
    > +#define MBOX_REG_TXLOCK 40
    > +#define MBOX_REG_TXUNLOCK 44
    > +
    > +/* offset of rx mailbox interrupt registers */
    > +#define MBOX_REG_TXINT 48
    > +
    > +#define MBOX_RX_TX_FULL 1
    > +#define MBOX_INT_ENABLE 1
    > +
    > +#define MBOX_LOCK_RESET (-1)
    > +#define MBOX_WAIT_TIMEOUT (1)
    > +
    > +#define RXBUF_LEN 32
    > +#define MAX_LINKS 1
    > +
    > +struct samsung_mlink {
    > + const char *name;
    > + struct ipc_link link;
    > + struct samsung_mbox *smc;
    > + int irq;
    > + void *data;
    > +};
    > +
    > +struct samsung_mbox {
    > + struct device *dev;
    > + void __iomem *ipc_base;
    > + struct ipc_controller ipc_con;
    > + struct mutex lock;
    > + struct samsung_mlink samsung_link[MAX_LINKS];
    > +};
    > +
    > +static inline struct samsung_mlink *to_samsung_mlink(struct ipc_link *plink)
    > +{
    > + if (!plink)
    > + return NULL;
    > +
    > + return container_of(plink, struct samsung_mlink, link);
    > +}
    > +
    > +static inline struct samsung_mbox *to_samsung_mbox(struct ipc_link *plink)
    > +{
    > + if (!plink)
    > + return NULL;
    > +
    > + return to_samsung_mlink(plink)->smc;
    > +}
    > +
    > +static void samsung_mbox_read(struct samsung_mlink *link)
    > +{
    > + u64 data;
    > + void __iomem *ipc_base = link->smc->ipc_base;
    > +
    > + /* Read both words which have information specific to client */
    > + data = readq(ipc_base + MBOX_REG_RXDATA0);
    > + link->data = phys_to_virt((phys_addr_t)data);
    > +}
    > +
    > +static irqreturn_t samsung_ipc_handler(int irq, void *p)
    > +{
    > + struct samsung_mlink *plink = p;
    > + void __iomem *ipc_base = plink->smc->ipc_base;
    > +
    > + samsung_mbox_read(plink);
    > + ipc_link_received_data(&plink->link, plink->data);
    > +
    > + /* Acknowledge the interrupt by clearing the interrupt register */
    > + writel(~MBOX_INT_ENABLE, ipc_base + MBOX_REG_RXINT);
    > + writel(readl(ipc_base + MBOX_REG_RXLOCK),
    > + ipc_base + MBOX_REG_RXUNLOCK);
    > +
    > + return IRQ_HANDLED;
    > +}
    > +
    > +static bool samsung_mbox_is_ready(struct ipc_link *link)
    > +{
    > + struct samsung_mbox *samsung_mbox = to_samsung_mbox(link);
    > + void __iomem *ipc_base = samsung_mbox->ipc_base;
    > + int ret = true;
    > +
    > + mutex_lock(&samsung_mbox->lock);
    > +
    > + /* If the RX interrupt register is clear then mbox is empty */
    > + if (readl(ipc_base + MBOX_REG_TXLOCK) &&
    > + readl(ipc_base + MBOX_REG_TXINT))
    > + ret = false;
    > +
    > + mutex_unlock(&samsung_mbox->lock);
    > + return ret;
    > +}
    > +
    > +static int samsung_mbox_send_data(struct ipc_link *link, void *msg)
    > +{
    > + u32 val;
    > + phys_addr_t addr;
    > + unsigned long timeout;
    > + struct samsung_mbox *samsung_mbox = to_samsung_mbox(link);
    > + void __iomem *ipc_base = samsung_mbox->ipc_base;
    > + int ret = 0;
    > +
    > + mutex_lock(&samsung_mbox->lock);
    > +
    > + timeout = jiffies + msecs_to_jiffies(MBOX_WAIT_TIMEOUT);
    > +
    > + /* Check if the mailbox is busy transmitting data */
    > + if (readl(ipc_base + MBOX_REG_TXLOCK)) {
    > + ret = -EBUSY;
    > + goto unlock_mutex;
    > + }
    > +
    > + addr = virt_to_phys(msg);
    > + val = samsung_get_client_id(msg);
    > +
    > + /* Lock the mailbox for this transaction with the client id */
    > + writel(val, ipc_base + MBOX_REG_TXLOCK);
    > + do {
    > + if (time_after(jiffies, timeout)) {
    > + pr_err("cannot aquire the lock\n");
    > + ret = -EAGAIN;
    > + goto unlock_mutex;
    > + }
    > + } while (readl(ipc_base + MBOX_REG_TXLOCK) != val);
    > +
    > + writeq(addr, ipc_base + MBOX_REG_TXDATA0);
    > + val = readl(ipc_base + MBOX_REG_TXINT);
    > + val |= MBOX_INT_ENABLE;
    > + writel(val, ipc_base + MBOX_REG_TXINT);
    > +
    > +unlock_mutex:
    > + mutex_unlock(&samsung_mbox->lock);
    > + return ret;
    > +}
    > +
    > +static int samsung_mbox_startup(struct ipc_link *link, void *ignored)
    > +{
    > + int ret;
    > + struct samsung_mlink *samsung_link = to_samsung_mlink(link);
    > + struct samsung_mbox *samsung_mbox = to_samsung_mbox(link);
    > + void __iomem *ipc_base = samsung_mbox->ipc_base;
    > + struct device *dev = samsung_mbox->dev;
    > +
    > + mutex_lock(&samsung_mbox->lock);
    > +
    > + ret = devm_request_irq(dev, samsung_link->irq, samsung_ipc_handler,
    > + IRQF_SHARED, link->link_name,
    > + samsung_link);
    > + if (unlikely(ret)) {
    > + pr_err("failed to register mailbox interrupt:%d\n", ret);
    > + mutex_unlock(&samsung_mbox->lock);
    > + return ret;
    > + }
    > +
    > + /*
    > + * On shutdown irrespective of what is the previous lock id
    > + * clear it. Dont have to do the same for RX lock. Remote
    > + * processor shall handle the RX lock clear on shutdown.
    > + */
    > + writel(~MBOX_INT_ENABLE, ipc_base + MBOX_REG_TXINT);
    > + writel(MBOX_LOCK_RESET, ipc_base + MBOX_REG_TXUNLOCK);
    > +
    > + mutex_unlock(&samsung_mbox->lock);
    > + return 0;
    > +}
    > +
    > +static void samsung_mbox_shutdown(struct ipc_link *link)
    > +{
    > + struct samsung_mbox *samsung_mbox = to_samsung_mbox(link);
    > + struct samsung_mlink *samsung_link = to_samsung_mlink(link);
    > + void __iomem *ipc_base = samsung_mbox->ipc_base;
    > + struct device *dev = samsung_mbox->dev;
    > +
    > + mutex_lock(&samsung_mbox->lock);
    > +
    > + /*
    > + * On shutdown irrespective of what is the previous lock id
    > + * clear it. Dont have to do the same for RX lock. Remote
    > + * processor shall handle the RX lock clear on shutdown.
    > + */
    > + writel(~MBOX_INT_ENABLE, ipc_base + MBOX_REG_TXINT);
    > + writel(MBOX_LOCK_RESET, ipc_base + MBOX_REG_TXUNLOCK);
    > +
    > + devm_free_irq(dev, samsung_link->irq, samsung_link);
    > +
    > + mutex_unlock(&samsung_mbox->lock);
    > +}
    > +
    > +static struct ipc_link_ops samsung_mbox_ops = {
    > + .is_ready = samsung_mbox_is_ready,
    > + .send_data = samsung_mbox_send_data,
    > + .startup = samsung_mbox_startup,
    > + .shutdown = samsung_mbox_shutdown,
    > +};
    > +
    > +static int samsung_mbox_probe(struct platform_device *pdev)
    > +{
    > + struct samsung_mbox *samsung_mbox;
    > + struct samsung_mlink *mbox_link;
    > + struct resource res;
    > + struct ipc_link **link;
    > + int loop, count, ret = 0;
    > + struct device_node *node = pdev->dev.of_node;
    > +
    > + if (!node) {
    > + dev_err(&pdev->dev, "driver doesnt support"
    > + "non-dt devices\n");
    > + return -ENODEV;
    > + }
    > +
    > + count = of_property_count_strings(node,
    > + "samsung,mbox-names");
    > + if (count <= 0) {
    > + dev_err(&pdev->dev, "no mbox devices found\n");
    > + return -ENODEV;
    > + }
    > +
    > + samsung_mbox = devm_kzalloc(&pdev->dev,
    > + sizeof(struct samsung_mbox), GFP_KERNEL);
    > + if (IS_ERR(samsung_mbox))
    > + return PTR_ERR(samsung_mbox);
    > +
    > + link = devm_kzalloc(&pdev->dev, (count + 1) * sizeof(*link),
    > + GFP_KERNEL);
    > + if (IS_ERR(link))
    > + return PTR_ERR(link);
    > +
    > + samsung_mbox->dev = &pdev->dev;
    > +
    > + samsung_mbox->ipc_base = devm_ioremap_resource(&pdev->dev, &res);
    > + if (IS_ERR(samsung_mbox->ipc_base))
    > + return PTR_ERR(samsung_mbox->ipc_base);
    > +
    > + for (loop = 0; loop < count; loop++) {
    > + mbox_link = &samsung_mbox->samsung_link[loop];
    > +
    > + ret = of_address_to_resource(node, 0, &res);
    > + if (ret < 0)
    > + return ret;

    Sorry posted a wrong version. Above code should be moved before ioremap

    > +
    > + mbox_link->irq = irq_of_parse_and_map(node, loop);
    > + if (!mbox_link->irq)
    > + return -ENODEV;
    > +
    > + mbox_link->smc = samsung_mbox;
    > + link[loop] = &mbox_link->link;
    > +
    > + if (of_property_read_string_index(node, "samsung,mbox-names",
    > + loop, &mbox_link->name)) {
    > + dev_err(&pdev->dev,
    > + "mbox_name [%d] read failed\n", loop);
    > + return -ENODEV;
    > + }
    > +
    > + snprintf(link[loop]->link_name, 16, mbox_link->name);
    > + }
    > +
    > + link[loop] = NULL; /* Terminating link */
    > +
    > + mutex_init(&samsung_mbox->lock);
    > + samsung_mbox->ipc_con.links = link;
    > + samsung_mbox->ipc_con.txdone_irq = false;
    > + samsung_mbox->ipc_con.txdone_poll = true;
    > + samsung_mbox->ipc_con.txpoll_period = 1;
    > + samsung_mbox->ipc_con.ops = &samsung_mbox_ops;
    > + snprintf(samsung_mbox->ipc_con.controller_name, 16, "samsung_mbox");
    > +
    > + ret = ipc_links_register(&samsung_mbox->ipc_con);
    > + if (ret) {
    > + pr_err("%s: IPC Link register failed\n", __func__);
    > + return ret;
    > + }
    > +
    > + platform_set_drvdata(pdev, samsung_mbox);
    > +
    > + return ret;
    > +}
    > +
    > +static int samsung_mbox_remove(struct platform_device *pdev)
    > +{
    > + struct samsung_mbox *samsung_mbox = platform_get_drvdata(pdev);
    > +
    > + ipc_links_unregister(&samsung_mbox->ipc_con);
    > +
    > + return 0;
    > +}
    > +
    > +static const struct of_device_id mailbox_smc_match[] = {
    > + { .compatible = "samsung,gh7-mailbox" },
    > + {},
    > +};
    > +MODULE_DEVICE_TABLE(of, mailbox_smc_match);
    > +
    > +static struct platform_driver samsung_mbox_driver = {
    > + .probe = samsung_mbox_probe,
    > + .remove = samsung_mbox_remove,
    > + .driver = {
    > + .name = "gh7-mailbox",
    > + .of_match_table = mailbox_smc_match,
    > + },
    > +};
    > +
    > +module_platform_driver(samsung_mbox_driver);
    > +
    > +MODULE_LICENSE("GPL v2");
    > +MODULE_DESCRIPTION("Samsung Mailbox Driver");
    > +MODULE_AUTHOR("Girish K S <ks.giri@samsung.com>");
    > +MODULE_ALIAS("platform:gh7-mailbox");
    > diff --git a/include/linux/mailbox-samsung.h b/include/linux/mailbox-samsung.h
    > new file mode 100644
    > index 0000000..c3f2d2c
    > --- /dev/null
    > +++ b/include/linux/mailbox-samsung.h
    > @@ -0,0 +1,112 @@
    > +
    > +/*
    > + * This program is free software; you can redistribute it and/or modify it
    > + * under the terms and conditions of the GNU General Public License,
    > + * version 2, as published by the Free Software Foundation.
    > + *
    > + * This program is distributed in the hope 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.
    > + *
    > + * You should have received a copy of the GNU General Public License along with
    > + * this program. If not, see <http://www.gnu.org/licenses/>.
    > + */
    > +
    > +#ifndef _MAILBOX_SAMSUNG_H_
    > +#define _MAILBOX_SAMSUNG_H_
    > +
    > +#include <linux/slab.h>
    > +
    > +#define SAMSUNG_MB_RESP_LEN (4096)
    > +#define SAMSUNG_MB_DRV_ID (0xa5)
    > +#define SAMSUNG_MB_DRV_LEN (0x08)
    > +#define REQUEST_PAGE_ORDER (16)
    > +
    > +#define IRQ_TX (1)
    > +#define IRQ_RX (2)
    > +
    > +struct samsung_packet {
    > + u8 version;
    > + u8 client_id;
    > + u8 remote_id;
    > + u16 req_len;
    > + u64 resp_addr;
    > + u16 resp_len;
    > + u8 reserved[16];
    > + u8 checksum;
    > +};
    > +
    > +static inline unsigned long get_alligned_buffer(void)
    > +{
    > + return __get_free_pages(GFP_KERNEL, REQUEST_PAGE_ORDER);
    > +}
    > +
    > +static inline void put_alligned_buffer(unsigned long addr)
    > +{
    > + free_pages(addr, REQUEST_PAGE_ORDER);
    > +}
    > +
    > +static inline void samsung_put_version(void *buf, u8 version)
    > +{
    > + struct samsung_packet *data = buf;
    > + data->version = version;
    > +}
    > +
    > +static inline void samsung_put_client_id(void *buf, u8 id)
    > +{
    > + struct samsung_packet *data = buf;
    > + data->client_id = (SAMSUNG_MB_DRV_ID << SAMSUNG_MB_DRV_LEN) | id;
    > +}
    > +
    > +static inline void samsung_put_remote_id(void *buf, u8 id)
    > +{
    > + struct samsung_packet *data = buf;
    > + data->remote_id = id;
    > +}
    > +
    > +static inline void samsung_put_req_len(void *buf, u16 len)
    > +{
    > + struct samsung_packet *data = buf;
    > + data->req_len = len;
    > +}
    > +
    > +static inline void samsung_put_resp_addr(void *buf, u64 addr)
    > +{
    > + struct samsung_packet *data = buf;
    > + data->resp_addr = addr;
    > +}
    > +
    > +static inline void samsung_put_checksum(void *buf, u8 checksum)
    > +{
    > + struct samsung_packet *data = buf;
    > + data->checksum = checksum;
    > +}
    > +
    > +static inline int samsung_get_resp_size(void)
    > +{
    > + /* The response buffer length can be max upto 4kb */
    > + return SAMSUNG_MB_RESP_LEN;
    > +}
    > +
    > +static inline int samsung_get_resp_len(void *buf)
    > +{
    > + struct samsung_packet *data = buf;
    > +
    > + /* The actual lenght of response buffer is got from remote packet */
    > + return data->resp_len;
    > +}
    > +
    > +static inline u64 samsung_get_resp_addr(void *buf)
    > +{
    > + struct samsung_packet *data = buf;
    > + return data->resp_addr;
    > +}
    > +
    > +static inline int samsung_get_client_id(const void *buf)
    > +{
    > + const struct samsung_packet *data = buf;
    > + return data->client_id;
    > +}
    > +
    > +#endif
    > --
    > 1.7.10.4
    >
    > --
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