[PATCH 1/2] mailbox: samsung: added support for samsung mailbox
From: Girish K S
Date: Mon Mar 17 2014 - 08:03:19 EST
This patch adds support to the samsung mailbox driver.
Signed-off-by: Girish K S <ks.giri@xxxxxxxxxxx>
---
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;
+
+ 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@xxxxxxxxxxx>");
+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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