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authorKenneth Heitke <kheitke@codeaurora.org>2014-02-12 23:44:22 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-02-15 23:55:28 +0400
commit5a86bf343976b9c8ab2f240bc866451fa67e5573 (patch)
tree26868658105a10869ca43d9eaf72098674eeb458 /drivers/spmi/spmi.c
parenta2a720e15f59be60c7ae1c58b5b4ac1003dd5078 (diff)
downloadlinux-5a86bf343976b9c8ab2f240bc866451fa67e5573.tar.xz
spmi: Linux driver framework for SPMI
System Power Management Interface (SPMI) is a specification developed by the MIPI (Mobile Industry Process Interface) Alliance optimized for the real time control of Power Management ICs (PMIC). SPMI is a two-wire serial interface that supports up to 4 master devices and up to 16 logical slaves. The framework supports message APIs, multiple busses (1 controller per bus) and multiple clients/slave devices per controller. Signed-off-by: Kenneth Heitke <kheitke@codeaurora.org> Signed-off-by: Michael Bohan <mbohan@codeaurora.org> Signed-off-by: Josh Cartwright <joshc@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/spmi/spmi.c')
-rw-r--r--drivers/spmi/spmi.c609
1 files changed, 609 insertions, 0 deletions
diff --git a/drivers/spmi/spmi.c b/drivers/spmi/spmi.c
new file mode 100644
index 000000000000..6122c8f2f4e3
--- /dev/null
+++ b/drivers/spmi/spmi.c
@@ -0,0 +1,609 @@
+/* Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only 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.
+ */
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/idr.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/spmi.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+
+#include <dt-bindings/spmi/spmi.h>
+
+static DEFINE_IDA(ctrl_ida);
+
+static void spmi_dev_release(struct device *dev)
+{
+ struct spmi_device *sdev = to_spmi_device(dev);
+ kfree(sdev);
+}
+
+static const struct device_type spmi_dev_type = {
+ .release = spmi_dev_release,
+};
+
+static void spmi_ctrl_release(struct device *dev)
+{
+ struct spmi_controller *ctrl = to_spmi_controller(dev);
+ ida_simple_remove(&ctrl_ida, ctrl->nr);
+ kfree(ctrl);
+}
+
+static const struct device_type spmi_ctrl_type = {
+ .release = spmi_ctrl_release,
+};
+
+#ifdef CONFIG_PM_RUNTIME
+static int spmi_runtime_suspend(struct device *dev)
+{
+ struct spmi_device *sdev = to_spmi_device(dev);
+ int err;
+
+ err = pm_generic_runtime_suspend(dev);
+ if (err)
+ return err;
+
+ return spmi_command_sleep(sdev);
+}
+
+static int spmi_runtime_resume(struct device *dev)
+{
+ struct spmi_device *sdev = to_spmi_device(dev);
+ int err;
+
+ err = spmi_command_wakeup(sdev);
+ if (err)
+ return err;
+
+ return pm_generic_runtime_resume(dev);
+}
+#endif
+
+static const struct dev_pm_ops spmi_pm_ops = {
+ SET_RUNTIME_PM_OPS(
+ spmi_runtime_suspend,
+ spmi_runtime_resume,
+ NULL
+ )
+};
+
+static int spmi_device_match(struct device *dev, struct device_driver *drv)
+{
+ if (of_driver_match_device(dev, drv))
+ return 1;
+
+ if (drv->name)
+ return strncmp(dev_name(dev), drv->name,
+ SPMI_NAME_SIZE) == 0;
+
+ return 0;
+}
+
+/**
+ * spmi_device_add() - add a device previously constructed via spmi_device_alloc()
+ * @sdev: spmi_device to be added
+ */
+int spmi_device_add(struct spmi_device *sdev)
+{
+ struct spmi_controller *ctrl = sdev->ctrl;
+ int err;
+
+ dev_set_name(&sdev->dev, "%d-%02x", ctrl->nr, sdev->usid);
+
+ err = device_add(&sdev->dev);
+ if (err < 0) {
+ dev_err(&sdev->dev, "Can't add %s, status %d\n",
+ dev_name(&sdev->dev), err);
+ goto err_device_add;
+ }
+
+ dev_dbg(&sdev->dev, "device %s registered\n", dev_name(&sdev->dev));
+
+err_device_add:
+ return err;
+}
+EXPORT_SYMBOL_GPL(spmi_device_add);
+
+/**
+ * spmi_device_remove(): remove an SPMI device
+ * @sdev: spmi_device to be removed
+ */
+void spmi_device_remove(struct spmi_device *sdev)
+{
+ device_unregister(&sdev->dev);
+}
+EXPORT_SYMBOL_GPL(spmi_device_remove);
+
+static inline int
+spmi_cmd(struct spmi_controller *ctrl, u8 opcode, u8 sid)
+{
+ if (!ctrl || !ctrl->cmd || ctrl->dev.type != &spmi_ctrl_type)
+ return -EINVAL;
+
+ return ctrl->cmd(ctrl, opcode, sid);
+}
+
+static inline int spmi_read_cmd(struct spmi_controller *ctrl, u8 opcode,
+ u8 sid, u16 addr, u8 *buf, size_t len)
+{
+ if (!ctrl || !ctrl->read_cmd || ctrl->dev.type != &spmi_ctrl_type)
+ return -EINVAL;
+
+ return ctrl->read_cmd(ctrl, opcode, sid, addr, buf, len);
+}
+
+static inline int spmi_write_cmd(struct spmi_controller *ctrl, u8 opcode,
+ u8 sid, u16 addr, const u8 *buf, size_t len)
+{
+ if (!ctrl || !ctrl->write_cmd || ctrl->dev.type != &spmi_ctrl_type)
+ return -EINVAL;
+
+ return ctrl->write_cmd(ctrl, opcode, sid, addr, buf, len);
+}
+
+/**
+ * spmi_register_read() - register read
+ * @sdev: SPMI device.
+ * @addr: slave register address (5-bit address).
+ * @buf: buffer to be populated with data from the Slave.
+ *
+ * Reads 1 byte of data from a Slave device register.
+ */
+int spmi_register_read(struct spmi_device *sdev, u8 addr, u8 *buf)
+{
+ /* 5-bit register address */
+ if (addr > 0x1F)
+ return -EINVAL;
+
+ return spmi_read_cmd(sdev->ctrl, SPMI_CMD_READ, sdev->usid, addr,
+ buf, 1);
+}
+EXPORT_SYMBOL_GPL(spmi_register_read);
+
+/**
+ * spmi_ext_register_read() - extended register read
+ * @sdev: SPMI device.
+ * @addr: slave register address (8-bit address).
+ * @buf: buffer to be populated with data from the Slave.
+ * @len: the request number of bytes to read (up to 16 bytes).
+ *
+ * Reads up to 16 bytes of data from the extended register space on a
+ * Slave device.
+ */
+int spmi_ext_register_read(struct spmi_device *sdev, u8 addr, u8 *buf,
+ size_t len)
+{
+ /* 8-bit register address, up to 16 bytes */
+ if (len == 0 || len > 16)
+ return -EINVAL;
+
+ return spmi_read_cmd(sdev->ctrl, SPMI_CMD_EXT_READ, sdev->usid, addr,
+ buf, len);
+}
+EXPORT_SYMBOL_GPL(spmi_ext_register_read);
+
+/**
+ * spmi_ext_register_readl() - extended register read long
+ * @sdev: SPMI device.
+ * @addr: slave register address (16-bit address).
+ * @buf: buffer to be populated with data from the Slave.
+ * @len: the request number of bytes to read (up to 8 bytes).
+ *
+ * Reads up to 8 bytes of data from the extended register space on a
+ * Slave device using 16-bit address.
+ */
+int spmi_ext_register_readl(struct spmi_device *sdev, u16 addr, u8 *buf,
+ size_t len)
+{
+ /* 16-bit register address, up to 8 bytes */
+ if (len == 0 || len > 8)
+ return -EINVAL;
+
+ return spmi_read_cmd(sdev->ctrl, SPMI_CMD_EXT_READL, sdev->usid, addr,
+ buf, len);
+}
+EXPORT_SYMBOL_GPL(spmi_ext_register_readl);
+
+/**
+ * spmi_register_write() - register write
+ * @sdev: SPMI device
+ * @addr: slave register address (5-bit address).
+ * @data: buffer containing the data to be transferred to the Slave.
+ *
+ * Writes 1 byte of data to a Slave device register.
+ */
+int spmi_register_write(struct spmi_device *sdev, u8 addr, u8 data)
+{
+ /* 5-bit register address */
+ if (addr > 0x1F)
+ return -EINVAL;
+
+ return spmi_write_cmd(sdev->ctrl, SPMI_CMD_WRITE, sdev->usid, addr,
+ &data, 1);
+}
+EXPORT_SYMBOL_GPL(spmi_register_write);
+
+/**
+ * spmi_register_zero_write() - register zero write
+ * @sdev: SPMI device.
+ * @data: the data to be written to register 0 (7-bits).
+ *
+ * Writes data to register 0 of the Slave device.
+ */
+int spmi_register_zero_write(struct spmi_device *sdev, u8 data)
+{
+ return spmi_write_cmd(sdev->ctrl, SPMI_CMD_ZERO_WRITE, sdev->usid, 0,
+ &data, 1);
+}
+EXPORT_SYMBOL_GPL(spmi_register_zero_write);
+
+/**
+ * spmi_ext_register_write() - extended register write
+ * @sdev: SPMI device.
+ * @addr: slave register address (8-bit address).
+ * @buf: buffer containing the data to be transferred to the Slave.
+ * @len: the request number of bytes to read (up to 16 bytes).
+ *
+ * Writes up to 16 bytes of data to the extended register space of a
+ * Slave device.
+ */
+int spmi_ext_register_write(struct spmi_device *sdev, u8 addr, const u8 *buf,
+ size_t len)
+{
+ /* 8-bit register address, up to 16 bytes */
+ if (len == 0 || len > 16)
+ return -EINVAL;
+
+ return spmi_write_cmd(sdev->ctrl, SPMI_CMD_EXT_WRITE, sdev->usid, addr,
+ buf, len);
+}
+EXPORT_SYMBOL_GPL(spmi_ext_register_write);
+
+/**
+ * spmi_ext_register_writel() - extended register write long
+ * @sdev: SPMI device.
+ * @addr: slave register address (16-bit address).
+ * @buf: buffer containing the data to be transferred to the Slave.
+ * @len: the request number of bytes to read (up to 8 bytes).
+ *
+ * Writes up to 8 bytes of data to the extended register space of a
+ * Slave device using 16-bit address.
+ */
+int spmi_ext_register_writel(struct spmi_device *sdev, u16 addr, const u8 *buf,
+ size_t len)
+{
+ /* 4-bit Slave Identifier, 16-bit register address, up to 8 bytes */
+ if (len == 0 || len > 8)
+ return -EINVAL;
+
+ return spmi_write_cmd(sdev->ctrl, SPMI_CMD_EXT_WRITEL, sdev->usid,
+ addr, buf, len);
+}
+EXPORT_SYMBOL_GPL(spmi_ext_register_writel);
+
+/**
+ * spmi_command_reset() - sends RESET command to the specified slave
+ * @sdev: SPMI device.
+ *
+ * The Reset command initializes the Slave and forces all registers to
+ * their reset values. The Slave shall enter the STARTUP state after
+ * receiving a Reset command.
+ */
+int spmi_command_reset(struct spmi_device *sdev)
+{
+ return spmi_cmd(sdev->ctrl, SPMI_CMD_RESET, sdev->usid);
+}
+EXPORT_SYMBOL_GPL(spmi_command_reset);
+
+/**
+ * spmi_command_sleep() - sends SLEEP command to the specified SPMI device
+ * @sdev: SPMI device.
+ *
+ * The Sleep command causes the Slave to enter the user defined SLEEP state.
+ */
+int spmi_command_sleep(struct spmi_device *sdev)
+{
+ return spmi_cmd(sdev->ctrl, SPMI_CMD_SLEEP, sdev->usid);
+}
+EXPORT_SYMBOL_GPL(spmi_command_sleep);
+
+/**
+ * spmi_command_wakeup() - sends WAKEUP command to the specified SPMI device
+ * @sdev: SPMI device.
+ *
+ * The Wakeup command causes the Slave to move from the SLEEP state to
+ * the ACTIVE state.
+ */
+int spmi_command_wakeup(struct spmi_device *sdev)
+{
+ return spmi_cmd(sdev->ctrl, SPMI_CMD_WAKEUP, sdev->usid);
+}
+EXPORT_SYMBOL_GPL(spmi_command_wakeup);
+
+/**
+ * spmi_command_shutdown() - sends SHUTDOWN command to the specified SPMI device
+ * @sdev: SPMI device.
+ *
+ * The Shutdown command causes the Slave to enter the SHUTDOWN state.
+ */
+int spmi_command_shutdown(struct spmi_device *sdev)
+{
+ return spmi_cmd(sdev->ctrl, SPMI_CMD_SHUTDOWN, sdev->usid);
+}
+EXPORT_SYMBOL_GPL(spmi_command_shutdown);
+
+static int spmi_drv_probe(struct device *dev)
+{
+ const struct spmi_driver *sdrv = to_spmi_driver(dev->driver);
+ struct spmi_device *sdev = to_spmi_device(dev);
+ int err;
+
+ /* Ensure the slave is in ACTIVE state */
+ err = spmi_command_wakeup(sdev);
+ if (err)
+ goto fail_wakeup;
+
+ pm_runtime_get_noresume(dev);
+ pm_runtime_set_active(dev);
+ pm_runtime_enable(dev);
+
+ err = sdrv->probe(sdev);
+ if (err)
+ goto fail_probe;
+
+ return 0;
+
+fail_probe:
+ pm_runtime_disable(dev);
+ pm_runtime_set_suspended(dev);
+ pm_runtime_put_noidle(dev);
+fail_wakeup:
+ return err;
+}
+
+static int spmi_drv_remove(struct device *dev)
+{
+ const struct spmi_driver *sdrv = to_spmi_driver(dev->driver);
+
+ pm_runtime_get_sync(dev);
+ sdrv->remove(to_spmi_device(dev));
+ pm_runtime_put_noidle(dev);
+
+ pm_runtime_disable(dev);
+ pm_runtime_set_suspended(dev);
+ pm_runtime_put_noidle(dev);
+ return 0;
+}
+
+static struct bus_type spmi_bus_type = {
+ .name = "spmi",
+ .match = spmi_device_match,
+ .pm = &spmi_pm_ops,
+ .probe = spmi_drv_probe,
+ .remove = spmi_drv_remove,
+};
+
+/**
+ * spmi_controller_alloc() - Allocate a new SPMI device
+ * @ctrl: associated controller
+ *
+ * Caller is responsible for either calling spmi_device_add() to add the
+ * newly allocated controller, or calling spmi_device_put() to discard it.
+ */
+struct spmi_device *spmi_device_alloc(struct spmi_controller *ctrl)
+{
+ struct spmi_device *sdev;
+
+ sdev = kzalloc(sizeof(*sdev), GFP_KERNEL);
+ if (!sdev)
+ return NULL;
+
+ sdev->ctrl = ctrl;
+ device_initialize(&sdev->dev);
+ sdev->dev.parent = &ctrl->dev;
+ sdev->dev.bus = &spmi_bus_type;
+ sdev->dev.type = &spmi_dev_type;
+ return sdev;
+}
+EXPORT_SYMBOL_GPL(spmi_device_alloc);
+
+/**
+ * spmi_controller_alloc() - Allocate a new SPMI controller
+ * @parent: parent device
+ * @size: size of private data
+ *
+ * Caller is responsible for either calling spmi_controller_add() to add the
+ * newly allocated controller, or calling spmi_controller_put() to discard it.
+ * The allocated private data region may be accessed via
+ * spmi_controller_get_drvdata()
+ */
+struct spmi_controller *spmi_controller_alloc(struct device *parent,
+ size_t size)
+{
+ struct spmi_controller *ctrl;
+ int id;
+
+ if (WARN_ON(!parent))
+ return NULL;
+
+ ctrl = kzalloc(sizeof(*ctrl) + size, GFP_KERNEL);
+ if (!ctrl)
+ return NULL;
+
+ device_initialize(&ctrl->dev);
+ ctrl->dev.type = &spmi_ctrl_type;
+ ctrl->dev.bus = &spmi_bus_type;
+ ctrl->dev.parent = parent;
+ ctrl->dev.of_node = parent->of_node;
+ spmi_controller_set_drvdata(ctrl, &ctrl[1]);
+
+ id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL);
+ if (id < 0) {
+ dev_err(parent,
+ "unable to allocate SPMI controller identifier.\n");
+ spmi_controller_put(ctrl);
+ return NULL;
+ }
+
+ ctrl->nr = id;
+ dev_set_name(&ctrl->dev, "spmi-%d", id);
+
+ dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id);
+ return ctrl;
+}
+EXPORT_SYMBOL_GPL(spmi_controller_alloc);
+
+static void of_spmi_register_devices(struct spmi_controller *ctrl)
+{
+ struct device_node *node;
+ int err;
+
+ if (!ctrl->dev.of_node)
+ return;
+
+ for_each_available_child_of_node(ctrl->dev.of_node, node) {
+ struct spmi_device *sdev;
+ u32 reg[2];
+
+ dev_dbg(&ctrl->dev, "adding child %s\n", node->full_name);
+
+ err = of_property_read_u32_array(node, "reg", reg, 2);
+ if (err) {
+ dev_err(&ctrl->dev,
+ "node %s err (%d) does not have 'reg' property\n",
+ node->full_name, err);
+ continue;
+ }
+
+ if (reg[1] != SPMI_USID) {
+ dev_err(&ctrl->dev,
+ "node %s contains unsupported 'reg' entry\n",
+ node->full_name);
+ continue;
+ }
+
+ if (reg[0] >= SPMI_MAX_SLAVE_ID) {
+ dev_err(&ctrl->dev,
+ "invalid usid on node %s\n",
+ node->full_name);
+ continue;
+ }
+
+ dev_dbg(&ctrl->dev, "read usid %02x\n", reg[0]);
+
+ sdev = spmi_device_alloc(ctrl);
+ if (!sdev)
+ continue;
+
+ sdev->dev.of_node = node;
+ sdev->usid = (u8) reg[0];
+
+ err = spmi_device_add(sdev);
+ if (err) {
+ dev_err(&sdev->dev,
+ "failure adding device. status %d\n", err);
+ spmi_device_put(sdev);
+ }
+ }
+}
+
+/**
+ * spmi_controller_add() - Add an SPMI controller
+ * @ctrl: controller to be registered.
+ *
+ * Register a controller previously allocated via spmi_controller_alloc() with
+ * the SPMI core.
+ */
+int spmi_controller_add(struct spmi_controller *ctrl)
+{
+ int ret;
+
+ /* Can't register until after driver model init */
+ if (WARN_ON(!spmi_bus_type.p))
+ return -EAGAIN;
+
+ ret = device_add(&ctrl->dev);
+ if (ret)
+ return ret;
+
+ if (IS_ENABLED(CONFIG_OF))
+ of_spmi_register_devices(ctrl);
+
+ dev_dbg(&ctrl->dev, "spmi-%d registered: dev:%p\n",
+ ctrl->nr, &ctrl->dev);
+
+ return 0;
+};
+EXPORT_SYMBOL_GPL(spmi_controller_add);
+
+/* Remove a device associated with a controller */
+static int spmi_ctrl_remove_device(struct device *dev, void *data)
+{
+ struct spmi_device *spmidev = to_spmi_device(dev);
+ if (dev->type == &spmi_dev_type)
+ spmi_device_remove(spmidev);
+ return 0;
+}
+
+/**
+ * spmi_controller_remove(): remove an SPMI controller
+ * @ctrl: controller to remove
+ *
+ * Remove a SPMI controller. Caller is responsible for calling
+ * spmi_controller_put() to discard the allocated controller.
+ */
+void spmi_controller_remove(struct spmi_controller *ctrl)
+{
+ int dummy;
+
+ if (!ctrl)
+ return;
+
+ dummy = device_for_each_child(&ctrl->dev, NULL,
+ spmi_ctrl_remove_device);
+ device_del(&ctrl->dev);
+}
+EXPORT_SYMBOL_GPL(spmi_controller_remove);
+
+/**
+ * spmi_driver_register() - Register client driver with SPMI core
+ * @sdrv: client driver to be associated with client-device.
+ *
+ * This API will register the client driver with the SPMI framework.
+ * It is typically called from the driver's module-init function.
+ */
+int spmi_driver_register(struct spmi_driver *sdrv)
+{
+ sdrv->driver.bus = &spmi_bus_type;
+ return driver_register(&sdrv->driver);
+}
+EXPORT_SYMBOL_GPL(spmi_driver_register);
+
+static void __exit spmi_exit(void)
+{
+ bus_unregister(&spmi_bus_type);
+}
+module_exit(spmi_exit);
+
+static int __init spmi_init(void)
+{
+ return bus_register(&spmi_bus_type);
+}
+postcore_initcall(spmi_init);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("SPMI module");
+MODULE_ALIAS("platform:spmi");