Introduce ARM AMBA bus
This will allow to detect the amba device and use the right driver for it at runtime. The code is base on linux 3.5. Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
This commit is contained in:
Jean-Christophe PLAGNIOL-VILLARD
parent
298d15571d
commit
7492e86329
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@ -1,4 +1,5 @@
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obj-y += base/
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obj-$(CONFIG_ARM_AMBA) += amba/
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obj-y += net/
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obj-y += serial/
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obj-y += mtd/
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@ -0,0 +1,2 @@
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obj-y += bus.o
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@ -0,0 +1,210 @@
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/*
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* Copyright (C) 2003 Deep Blue Solutions Ltd, All Rights Reserved.
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* Copyright (c) 2012 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
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*
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* Under GPLv2.
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*/
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#include <common.h>
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#include <driver.h>
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#include <linux/clk.h>
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#include <linux/amba/bus.h>
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#include <io.h>
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#define to_amba_driver(d) container_of(d, struct amba_driver, drv)
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static const struct amba_id *
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amba_lookup(const struct amba_id *table, struct amba_device *dev)
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{
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int ret = 0;
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while (table->mask) {
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ret = (dev->periphid & table->mask) == table->id;
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if (ret)
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break;
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table++;
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}
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return ret ? table : NULL;
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}
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static int amba_match(struct device_d *dev, struct driver_d *drv)
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{
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struct amba_device *pcdev = to_amba_device(dev);
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struct amba_driver *pcdrv = to_amba_driver(drv);
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return amba_lookup(pcdrv->id_table, pcdev) == NULL;
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}
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static int amba_get_enable_pclk(struct amba_device *pcdev)
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{
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struct clk *pclk = clk_get(&pcdev->dev, "apb_pclk");
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int ret;
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pcdev->pclk = pclk;
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if (IS_ERR(pclk))
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return PTR_ERR(pclk);
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ret = clk_enable(pclk);
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if (ret) {
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clk_put(pclk);
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}
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return ret;
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}
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static int amba_probe(struct device_d *dev)
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{
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struct amba_device *pcdev = to_amba_device(dev);
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struct amba_driver *pcdrv = to_amba_driver(dev->driver);
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const struct amba_id *id = amba_lookup(pcdrv->id_table, pcdev);
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return pcdrv->probe(pcdev, id);
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}
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static void amba_remove(struct device_d *dev)
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{
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struct amba_device *pcdev = to_amba_device(dev);
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struct amba_driver *drv = to_amba_driver(dev->driver);
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drv->remove(pcdev);
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}
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struct bus_type amba_bustype = {
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.name = "amba",
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.match = amba_match,
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.probe = amba_probe,
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.remove = amba_remove,
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};
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int amba_driver_register(struct amba_driver *drv)
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{
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drv->drv.bus = &amba_bustype;
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if (drv->probe)
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drv->drv.probe = amba_probe;
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if (drv->remove)
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drv->drv.remove = amba_remove;
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return register_driver(&drv->drv);
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}
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/**
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* amba_device_add - add a previously allocated AMBA device structure
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* @dev: AMBA device allocated by amba_device_alloc
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* @parent: resource parent for this devices resources
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*
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* Claim the resource, and read the device cell ID if not already
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* initialized. Register the AMBA device with the Linux device
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* manager.
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*/
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int amba_device_add(struct amba_device *dev)
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{
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u32 size;
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void __iomem *tmp;
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int i, ret;
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struct resource *res = NULL;
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dev->dev.bus = &amba_bustype;
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/*
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* Dynamically calculate the size of the resource
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* and use this for iomap
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*/
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size = resource_size(&dev->res);
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res = request_iomem_region("amba", dev->res.start, dev->res.end);
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if (!res)
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return -ENOMEM;
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dev->base = tmp = (void __force __iomem *)res->start;
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if (!tmp) {
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ret = -ENOMEM;
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goto err_release;
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}
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/* Hard-coded primecell ID instead of plug-n-play */
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if (dev->periphid != 0)
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goto skip_probe;
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ret = amba_get_enable_pclk(dev);
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if (ret == 0) {
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u32 pid, cid;
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/*
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* Read pid and cid based on size of resource
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* they are located at end of region
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*/
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for (pid = 0, i = 0; i < 4; i++)
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pid |= (readl(tmp + size - 0x20 + 4 * i) & 255) <<
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(i * 8);
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for (cid = 0, i = 0; i < 4; i++)
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cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) <<
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(i * 8);
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if (cid == AMBA_CID)
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dev->periphid = pid;
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if (!dev->periphid)
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ret = -ENODEV;
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}
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if (ret)
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goto err_release;
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skip_probe:
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ret = register_device(&dev->dev);
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if (ret)
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goto err_release;
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return ret;
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err_release:
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release_region(res);
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return ret;
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}
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struct amba_device *
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amba_aphb_device_add(struct device_d *parent, const char *name, int id,
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resource_size_t base, size_t size,
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void *pdata, unsigned int periphid)
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{
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struct amba_device *dev;
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int ret;
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dev = amba_device_alloc(name, id, base, size);
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dev->periphid = periphid;
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dev->dev.platform_data = pdata;
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dev->dev.parent = parent;
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ret = amba_device_add(dev);
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if (ret)
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return ERR_PTR(ret);
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return dev;
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}
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/**
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* amba_device_alloc - allocate an AMBA device
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* @name: sysfs name of the AMBA device
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* @base: base of AMBA device
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* @size: size of AMBA device
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*
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* Allocate and initialize an AMBA device structure. Returns %NULL
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* on failure.
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*/
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struct amba_device *amba_device_alloc(const char *name, int id, resource_size_t base,
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size_t size)
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{
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struct amba_device *dev;
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dev = xzalloc(sizeof(*dev));
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strcpy(dev->dev.name, name);
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dev->dev.id = id;
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dev->res.start = base;
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dev->res.end = base + size - 1;
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dev->res.flags = IORESOURCE_MEM;
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return dev;
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}
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@ -0,0 +1,153 @@
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/*
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* linux/include/amba/bus.h
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*
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* This device type deals with ARM PrimeCells and anything else that
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* presents a proper CID (0xB105F00D) at the end of the I/O register
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* region or that is derived from a PrimeCell.
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*
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* Copyright (C) 2003 Deep Blue Solutions Ltd, All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#ifndef ASMARM_AMBA_H
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#define ASMARM_AMBA_H
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#include <linux/clk.h>
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#include <driver.h>
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#include <linux/err.h>
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#define AMBA_CID 0xb105f00d
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/**
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* struct amba_id - identifies a device on an AMBA bus
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* @id: The significant bits if the hardware device ID
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* @mask: Bitmask specifying which bits of the id field are significant when
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* matching. A driver binds to a device when ((hardware device ID) & mask)
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* == id.
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* @data: Private data used by the driver.
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*/
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struct amba_id {
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unsigned int id;
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unsigned int mask;
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void *data;
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};
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struct clk;
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struct amba_device {
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struct device_d dev;
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struct resource res;
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void __iomem *base;
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struct clk *pclk;
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unsigned int periphid;
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};
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struct amba_driver {
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struct driver_d drv;
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int (*probe)(struct amba_device *, const struct amba_id *);
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int (*remove)(struct amba_device *);
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const struct amba_id *id_table;
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};
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enum amba_vendor {
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AMBA_VENDOR_ARM = 0x41,
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AMBA_VENDOR_ST = 0x80,
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};
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extern struct bus_type amba_bustype;
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#define to_amba_device(d) container_of(d, struct amba_device, dev)
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#define amba_get_drvdata(d) dev_get_drvdata(&d->dev)
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#define amba_set_drvdata(d,p) dev_set_drvdata(&d->dev, p)
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int amba_driver_register(struct amba_driver *);
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void amba_driver_unregister(struct amba_driver *);
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struct amba_device *amba_device_alloc(const char *, int id, resource_size_t, size_t);
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void amba_device_put(struct amba_device *);
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int amba_device_add(struct amba_device *);
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int amba_device_register(struct amba_device *, struct resource *);
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struct amba_device *
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amba_aphb_device_add(struct device_d *parent, const char *name, int id,
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resource_size_t base, size_t size,
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void *pdata, unsigned int periphid);
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static inline struct amba_device *
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amba_apb_device_add(struct device_d *parent, const char *name, int id,
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resource_size_t base, size_t size,
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void *pdata, unsigned int periphid)
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{
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return amba_aphb_device_add(parent, name, id, base, size, pdata,
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periphid);
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}
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static inline struct amba_device *
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amba_ahb_device_add(struct device_d *parent, const char *name, int id,
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resource_size_t base, size_t size,
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void *pdata, unsigned int periphid)
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{
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return amba_aphb_device_add(parent, name, id, base, size, pdata,
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periphid);
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}
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void amba_device_unregister(struct amba_device *);
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struct amba_device *amba_find_device(const char *, struct device_d *, unsigned int, unsigned int);
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int amba_request_regions(struct amba_device *, const char *);
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void amba_release_regions(struct amba_device *);
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static inline void __iomem *amba_get_mem_region(struct amba_device *dev)
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{
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return dev->base;
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}
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#define amba_pclk_enable(d) \
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(IS_ERR((d)->pclk) ? 0 : clk_enable((d)->pclk))
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#define amba_pclk_disable(d) \
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do { if (!IS_ERR((d)->pclk)) clk_disable((d)->pclk); } while (0)
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/* Some drivers don't use the struct amba_device */
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#define AMBA_CONFIG_BITS(a) (((a) >> 24) & 0xff)
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#define AMBA_REV_BITS(a) (((a) >> 20) & 0x0f)
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#define AMBA_MANF_BITS(a) (((a) >> 12) & 0xff)
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#define AMBA_PART_BITS(a) ((a) & 0xfff)
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#define amba_config(d) AMBA_CONFIG_BITS((d)->periphid)
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#define amba_rev(d) AMBA_REV_BITS((d)->periphid)
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#define amba_manf(d) AMBA_MANF_BITS((d)->periphid)
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#define amba_part(d) AMBA_PART_BITS((d)->periphid)
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#define __AMBA_DEV(busid, data) \
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{ \
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.init_name = busid, \
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.platform_data = data, \
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}
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/*
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* APB devices do not themselves have the ability to address memory,
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* so DMA masks should be zero (much like USB peripheral devices.)
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* The DMA controller DMA masks should be used instead (much like
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* USB host controllers in conventional PCs.)
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*/
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#define AMBA_APB_DEVICE(name, busid, id, base, data) \
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struct amba_device name##_device = { \
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.dev = __AMBA_DEV(busid, data), \
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.res = DEFINE_RES_MEM(base, SZ_4K), \
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.periphid = id, \
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}
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/*
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* AHB devices are DMA capable, so set their DMA masks
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*/
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#define AMBA_AHB_DEVICE(name, busid, id, base, data) \
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struct amba_device name##_device = { \
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.dev = __AMBA_DEV(busid, data), \
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.res = DEFINE_RES_MEM(base, SZ_4K), \
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.periphid = id, \
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}
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#endif
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