HSI: hsi: Introducing HSI framework

Adds HSI framework in to the linux kernel.

High Speed Synchronous Serial Interface (HSI) is a
serial interface mainly used for connecting application
engines (APE) with cellular modem engines (CMT) in cellular
handsets.

HSI provides multiplexing for up to 16 logical channels,
low-latency and full duplex communication.

Signed-off-by: Carlos Chinea <carlos.chinea@nokia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 410 insertions, 0 deletions

diff --git a/include/linux/hsi/hsi.h b/include/linux/hsi/hsi.h
new file mode 100644
index 000000000000..4b178067f405
--- /dev/null
+++ b/include/linux/hsi/hsi.h
@@ -0,0 +1,410 @@
+/*
+ * HSI core header file.
+ *
+ * Copyright (C) 2010 Nokia Corporation. All rights reserved.
+ *
+ * Contact: Carlos Chinea <carlos.chinea@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#ifndef __LINUX_HSI_H__
+#define __LINUX_HSI_H__
+
+#include <linux/device.h>
+#include <linux/mutex.h>
+#include <linux/scatterlist.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/module.h>
+
+/* HSI message ttype */
+#define HSI_MSG_READ    0
+#define HSI_MSG_WRITE   1
+
+/* HSI configuration values */
+enum {
+        HSI_MODE_STREAM = 1,
+        HSI_MODE_FRAME,
+};
+
+enum {
+        HSI_FLOW_SYNC,  /* Synchronized flow */
+        HSI_FLOW_PIPE,  /* Pipelined flow */
+};
+
+enum {
+        HSI_ARB_RR,     /* Round-robin arbitration */
+        HSI_ARB_PRIO,   /* Channel priority arbitration */
+};
+
+#define HSI_MAX_CHANNELS        16
+
+/* HSI message status codes */
+enum {
+        HSI_STATUS_COMPLETED,   /* Message transfer is completed */
+        HSI_STATUS_PENDING,     /* Message pending to be read/write (POLL) */
+        HSI_STATUS_PROCEEDING,  /* Message transfer is ongoing */
+        HSI_STATUS_QUEUED,      /* Message waiting to be served */
+        HSI_STATUS_ERROR,       /* Error when message transfer was ongoing */
+};
+
+/* HSI port event codes */
+enum {
+        HSI_EVENT_START_RX,
+        HSI_EVENT_STOP_RX,
+};
+
+/**
+ * struct hsi_config - Configuration for RX/TX HSI modules
+ * @mode: Bit transmission mode (STREAM or FRAME)
+ * @channels: Number of channels to use [1..16]
+ * @speed: Max bit transmission speed (Kbit/s)
+ * @flow: RX flow type (SYNCHRONIZED or PIPELINE)
+ * @arb_mode: Arbitration mode for TX frame (Round robin, priority)
+ */
+struct hsi_config {
+        unsigned int    mode;
+        unsigned int    channels;
+        unsigned int    speed;
+        union {
+                unsigned int    flow;           /* RX only */
+                unsigned int    arb_mode;       /* TX only */
+        };
+};
+
+/**
+ * struct hsi_board_info - HSI client board info
+ * @name: Name for the HSI device
+ * @hsi_id: HSI controller id where the client sits
+ * @port: Port number in the controller where the client sits
+ * @tx_cfg: HSI TX configuration
+ * @rx_cfg: HSI RX configuration
+ * @platform_data: Platform related data
+ * @archdata: Architecture-dependent device data
+ */
+struct hsi_board_info {
+        const char              *name;
+        unsigned int            hsi_id;
+        unsigned int            port;
+        struct hsi_config       tx_cfg;
+        struct hsi_config       rx_cfg;
+        void                    *platform_data;
+        struct dev_archdata     *archdata;
+};
+
+#ifdef CONFIG_HSI_BOARDINFO
+extern int hsi_register_board_info(struct hsi_board_info const *info,
+                                                        unsigned int len);
+#else
+static inline int hsi_register_board_info(struct hsi_board_info const *info,
+                                                        unsigned int len)
+{
+        return 0;
+}
+#endif /* CONFIG_HSI_BOARDINFO */
+
+/**
+ * struct hsi_client - HSI client attached to an HSI port
+ * @device: Driver model representation of the device
+ * @tx_cfg: HSI TX configuration
+ * @rx_cfg: HSI RX configuration
+ * @hsi_start_rx: Called after incoming wake line goes high
+ * @hsi_stop_rx: Called after incoming wake line goes low
+ */
+struct hsi_client {
+        struct device           device;
+        struct hsi_config       tx_cfg;
+        struct hsi_config       rx_cfg;
+        void                    (*hsi_start_rx)(struct hsi_client *cl);
+        void                    (*hsi_stop_rx)(struct hsi_client *cl);
+        /* private: */
+        unsigned int            pclaimed:1;
+        struct list_head        link;
+};
+
+#define to_hsi_client(dev) container_of(dev, struct hsi_client, device)
+
+static inline void hsi_client_set_drvdata(struct hsi_client *cl, void *data)
+{
+        dev_set_drvdata(&cl->device, data);
+}
+
+static inline void *hsi_client_drvdata(struct hsi_client *cl)
+{
+        return dev_get_drvdata(&cl->device);
+}
+
+/**
+ * struct hsi_client_driver - Driver associated to an HSI client
+ * @driver: Driver model representation of the driver
+ */
+struct hsi_client_driver {
+        struct device_driver    driver;
+};
+
+#define to_hsi_client_driver(drv) container_of(drv, struct hsi_client_driver,\
+                                                                        driver)
+
+int hsi_register_client_driver(struct hsi_client_driver *drv);
+
+static inline void hsi_unregister_client_driver(struct hsi_client_driver *drv)
+{
+        driver_unregister(&drv->driver);
+}
+
+/**
+ * struct hsi_msg - HSI message descriptor
+ * @link: Free to use by the current descriptor owner
+ * @cl: HSI device client that issues the transfer
+ * @sgt: Head of the scatterlist array
+ * @context: Client context data associated to the transfer
+ * @complete: Transfer completion callback
+ * @destructor: Destructor to free resources when flushing
+ * @status: Status of the transfer when completed
+ * @actual_len: Actual length of data transfered on completion
+ * @channel: Channel were to TX/RX the message
+ * @ttype: Transfer type (TX if set, RX otherwise)
+ * @break_frame: if true HSI will send/receive a break frame. Data buffers are
+ *              ignored in the request.
+ */
+struct hsi_msg {
+        struct list_head        link;
+        struct hsi_client       *cl;
+        struct sg_table         sgt;
+        void                    *context;
+
+        void                    (*complete)(struct hsi_msg *msg);
+        void                    (*destructor)(struct hsi_msg *msg);
+
+        int                     status;
+        unsigned int            actual_len;
+        unsigned int            channel;
+        unsigned int            ttype:1;
+        unsigned int            break_frame:1;
+};
+
+struct hsi_msg *hsi_alloc_msg(unsigned int n_frag, gfp_t flags);
+void hsi_free_msg(struct hsi_msg *msg);
+
+/**
+ * struct hsi_port - HSI port device
+ * @device: Driver model representation of the device
+ * @tx_cfg: Current TX path configuration
+ * @rx_cfg: Current RX path configuration
+ * @num: Port number
+ * @shared: Set when port can be shared by different clients
+ * @claimed: Reference count of clients which claimed the port
+ * @lock: Serialize port claim
+ * @async: Asynchronous transfer callback
+ * @setup: Callback to set the HSI client configuration
+ * @flush: Callback to clean the HW state and destroy all pending transfers
+ * @start_tx: Callback to inform that a client wants to TX data
+ * @stop_tx: Callback to inform that a client no longer wishes to TX data
+ * @release: Callback to inform that a client no longer uses the port
+ * @clients: List of hsi_clients using the port.
+ * @clock: Lock to serialize access to the clients list.
+ */
+struct hsi_port {
+        struct device                   device;
+        struct hsi_config               tx_cfg;
+        struct hsi_config               rx_cfg;
+        unsigned int                    num;
+        unsigned int                    shared:1;
+        int                             claimed;
+        struct mutex                    lock;
+        int                             (*async)(struct hsi_msg *msg);
+        int                             (*setup)(struct hsi_client *cl);
+        int                             (*flush)(struct hsi_client *cl);
+        int                             (*start_tx)(struct hsi_client *cl);
+        int                             (*stop_tx)(struct hsi_client *cl);
+        int                             (*release)(struct hsi_client *cl);
+        struct list_head                clients;
+        spinlock_t                      clock;
+};
+
+#define to_hsi_port(dev) container_of(dev, struct hsi_port, device)
+#define hsi_get_port(cl) to_hsi_port((cl)->device.parent)
+
+void hsi_event(struct hsi_port *port, unsigned int event);
+int hsi_claim_port(struct hsi_client *cl, unsigned int share);
+void hsi_release_port(struct hsi_client *cl);
+
+static inline int hsi_port_claimed(struct hsi_client *cl)
+{
+        return cl->pclaimed;
+}
+
+static inline void hsi_port_set_drvdata(struct hsi_port *port, void *data)
+{
+        dev_set_drvdata(&port->device, data);
+}
+
+static inline void *hsi_port_drvdata(struct hsi_port *port)
+{
+        return dev_get_drvdata(&port->device);
+}
+
+/**
+ * struct hsi_controller - HSI controller device
+ * @device: Driver model representation of the device
+ * @owner: Pointer to the module owning the controller
+ * @id: HSI controller ID
+ * @num_ports: Number of ports in the HSI controller
+ * @port: Array of HSI ports
+ */
+struct hsi_controller {
+        struct device           device;
+        struct module           *owner;
+        unsigned int            id;
+        unsigned int            num_ports;
+        struct hsi_port         *port;
+};
+
+#define to_hsi_controller(dev) container_of(dev, struct hsi_controller, device)
+
+struct hsi_controller *hsi_alloc_controller(unsigned int n_ports, gfp_t flags);
+void hsi_free_controller(struct hsi_controller *hsi);
+int hsi_register_controller(struct hsi_controller *hsi);
+void hsi_unregister_controller(struct hsi_controller *hsi);
+
+static inline void hsi_controller_set_drvdata(struct hsi_controller *hsi,
+                                                                void *data)
+{
+        dev_set_drvdata(&hsi->device, data);
+}
+
+static inline void *hsi_controller_drvdata(struct hsi_controller *hsi)
+{
+        return dev_get_drvdata(&hsi->device);
+}
+
+static inline struct hsi_port *hsi_find_port_num(struct hsi_controller *hsi,
+                                                        unsigned int num)
+{
+        return (num < hsi->num_ports) ? &hsi->port[num] : NULL;
+}
+
+/*
+ * API for HSI clients
+ */
+int hsi_async(struct hsi_client *cl, struct hsi_msg *msg);
+
+/**
+ * hsi_id - Get HSI controller ID associated to a client
+ * @cl: Pointer to a HSI client
+ *
+ * Return the controller id where the client is attached to
+ */
+static inline unsigned int hsi_id(struct hsi_client *cl)
+{
+        return  to_hsi_controller(cl->device.parent->parent)->id;
+}
+
+/**
+ * hsi_port_id - Gets the port number a client is attached to
+ * @cl: Pointer to HSI client
+ *
+ * Return the port number associated to the client
+ */
+static inline unsigned int hsi_port_id(struct hsi_client *cl)
+{
+        return  to_hsi_port(cl->device.parent)->num;
+}
+
+/**
+ * hsi_setup - Configure the client's port
+ * @cl: Pointer to the HSI client
+ *
+ * When sharing ports, clients should either relay on a single
+ * client setup or have the same setup for all of them.
+ *
+ * Return -errno on failure, 0 on success
+ */
+static inline int hsi_setup(struct hsi_client *cl)
+{
+        if (!hsi_port_claimed(cl))
+                return -EACCES;
+        return  hsi_get_port(cl)->setup(cl);
+}
+
+/**
+ * hsi_flush - Flush all pending transactions on the client's port
+ * @cl: Pointer to the HSI client
+ *
+ * This function will destroy all pending hsi_msg in the port and reset
+ * the HW port so it is ready to receive and transmit from a clean state.
+ *
+ * Return -errno on failure, 0 on success
+ */
+static inline int hsi_flush(struct hsi_client *cl)
+{
+        if (!hsi_port_claimed(cl))
+                return -EACCES;
+        return hsi_get_port(cl)->flush(cl);
+}
+
+/**
+ * hsi_async_read - Submit a read transfer
+ * @cl: Pointer to the HSI client
+ * @msg: HSI message descriptor of the transfer
+ *
+ * Return -errno on failure, 0 on success
+ */
+static inline int hsi_async_read(struct hsi_client *cl, struct hsi_msg *msg)
+{
+        msg->ttype = HSI_MSG_READ;
+        return hsi_async(cl, msg);
+}
+
+/**
+ * hsi_async_write - Submit a write transfer
+ * @cl: Pointer to the HSI client
+ * @msg: HSI message descriptor of the transfer
+ *
+ * Return -errno on failure, 0 on success
+ */
+static inline int hsi_async_write(struct hsi_client *cl, struct hsi_msg *msg)
+{
+        msg->ttype = HSI_MSG_WRITE;
+        return hsi_async(cl, msg);
+}
+
+/**
+ * hsi_start_tx - Signal the port that the client wants to start a TX
+ * @cl: Pointer to the HSI client
+ *
+ * Return -errno on failure, 0 on success
+ */
+static inline int hsi_start_tx(struct hsi_client *cl)
+{
+        if (!hsi_port_claimed(cl))
+                return -EACCES;
+        return hsi_get_port(cl)->start_tx(cl);
+}
+
+/**
+ * hsi_stop_tx - Signal the port that the client no longer wants to transmit
+ * @cl: Pointer to the HSI client
+ *
+ * Return -errno on failure, 0 on success
+ */
+static inline int hsi_stop_tx(struct hsi_client *cl)
+{
+        if (!hsi_port_claimed(cl))
+                return -EACCES;
+        return hsi_get_port(cl)->stop_tx(cl);
+}
+#endif /* __LINUX_HSI_H__ */