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 <[email protected]> --- drivers/Makefile | 1 + drivers/amba/Makefile | 2 + drivers/amba/bus.c | 212 ++++++++++++++++++++++++++++++++++++++++++++++ include/linux/amba/bus.h | 157 ++++++++++++++++++++++++++++++++++ 4 files changed, 372 insertions(+) create mode 100644 drivers/amba/Makefile create mode 100644 drivers/amba/bus.c create mode 100644 include/linux/amba/bus.h diff --git a/drivers/Makefile b/drivers/Makefile index 005ab24..ceb8f82 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -1,4 +1,5 @@ obj-y += base/ +obj-$(CONFIG_ARM_AMBA) += amba/ obj-y += net/ obj-y += serial/ obj-y += mtd/ diff --git a/drivers/amba/Makefile b/drivers/amba/Makefile new file mode 100644 index 0000000..a4a511b --- /dev/null +++ b/drivers/amba/Makefile @@ -0,0 +1,2 @@ + +obj-y += bus.o diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c new file mode 100644 index 0000000..6cde349 --- /dev/null +++ b/drivers/amba/bus.c @@ -0,0 +1,212 @@ +/* + * Copyright (C) 2003 Deep Blue Solutions Ltd, All Rights Reserved. + * Copyright (c) 2012 Jean-Christophe PLAGNIOL-VILLARD <[email protected]> + * + * Under GPLv2. + */ +#include <common.h> +#include <driver.h> +#include <linux/clk.h> +#include <linux/amba/bus.h> +#include <io.h> + +#define to_amba_driver(d) container_of(d, struct amba_driver, drv) + +static const struct amba_id * +amba_lookup(const struct amba_id *table, struct amba_device *dev) +{ + int ret = 0; + + while (table->mask) { + ret = (dev->periphid & table->mask) == table->id; + if (ret) + break; + table++; + } + + return ret ? table : NULL; +} + +static int amba_match(struct device_d *dev, struct driver_d *drv) +{ + struct amba_device *pcdev = to_amba_device(dev); + + struct amba_driver *pcdrv = to_amba_driver(drv); + + return amba_lookup(pcdrv->id_table, pcdev) == NULL; +} + +static int amba_get_enable_pclk(struct amba_device *pcdev) +{ + struct clk *pclk = clk_get(&pcdev->dev, "apb_pclk"); + int ret; + + pcdev->pclk = pclk; + + if (IS_ERR(pclk)) + return PTR_ERR(pclk); + + ret = clk_enable(pclk); + if (ret) { + clk_put(pclk); + } + + return ret; +} + +static int amba_probe(struct device_d *dev) +{ + struct amba_device *pcdev = to_amba_device(dev); + struct amba_driver *pcdrv = to_amba_driver(dev->driver); + const struct amba_id *id = amba_lookup(pcdrv->id_table, pcdev); + + return pcdrv->probe(pcdev, id); +} + +static void amba_remove(struct device_d *dev) +{ + struct amba_device *pcdev = to_amba_device(dev); + struct amba_driver *drv = to_amba_driver(dev->driver); + + drv->remove(pcdev); +} + +struct bus_type amba_bustype = { + .name = "amba", + .match = amba_match, + .probe = amba_probe, + .remove = amba_remove, +}; + +int amba_driver_register(struct amba_driver *drv) +{ + drv->drv.bus = &amba_bustype; +#define SETFN(fn) if (drv->fn) drv->drv.fn = amba_##fn + SETFN(probe); + SETFN(remove); + + return register_driver(&drv->drv); +} + +/** + * amba_device_add - add a previously allocated AMBA device structure + * @dev: AMBA device allocated by amba_device_alloc + * @parent: resource parent for this devices resources + * + * Claim the resource, and read the device cell ID if not already + * initialized. Register the AMBA device with the Linux device + * manager. + */ +int amba_device_add(struct amba_device *dev) +{ + u32 size; + void __iomem *tmp; + int i, ret; + struct resource *res = NULL; + + dev->dev.bus = &amba_bustype; + + /* + * Dynamically calculate the size of the resource + * and use this for iomap + */ + size = resource_size(&dev->res); + res = request_iomem_region("amba", dev->res.start, dev->res.end); + if (!res) + return -ENOMEM; + dev->base = tmp = (void __force __iomem *)res->start; + if (!tmp) { + ret = -ENOMEM; + goto err_release; + } + + /* Hard-coded primecell ID instead of plug-n-play */ + if (dev->periphid != 0) + goto skip_probe; + + ret = amba_get_enable_pclk(dev); + if (ret == 0) { + u32 pid, cid; + + /* + * Read pid and cid based on size of resource + * they are located at end of region + */ + for (pid = 0, i = 0; i < 4; i++) + pid |= (readl(tmp + size - 0x20 + 4 * i) & 255) << + (i * 8); + for (cid = 0, i = 0; i < 4; i++) + cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) << + (i * 8); + + if (cid == AMBA_CID) + dev->periphid = pid; + + if (!dev->periphid) + ret = -ENODEV; + } + + if (ret) + goto err_release; + + skip_probe: + ret = register_device(&dev->dev); + if (ret) + goto err_release; + + return ret; + err_release: + release_region(res); + return ret; +} + +struct amba_device * +amba_aphb_device_add(struct device_d *parent, const char *name, int id, + resource_size_t base, size_t size, + void *pdata, unsigned int periphid) +{ + struct amba_device *dev; + int ret; + + dev = amba_device_alloc(name, id, base, size); + if (!dev) + return ERR_PTR(-ENOMEM); + + dev->periphid = periphid; + dev->dev.platform_data = pdata; + dev->dev.parent = parent; + + ret = amba_device_add(dev); + if (ret) { + return ERR_PTR(ret); + } + + return dev; +} + +/** + * amba_device_alloc - allocate an AMBA device + * @name: sysfs name of the AMBA device + * @base: base of AMBA device + * @size: size of AMBA device + * + * Allocate and initialize an AMBA device structure. Returns %NULL + * on failure. + */ +struct amba_device *amba_device_alloc(const char *name, int id, resource_size_t base, + size_t size) +{ + struct amba_device *dev; + + dev = xzalloc(sizeof(*dev)); + if (dev) { + strcpy(dev->dev.name, name); + dev->dev.id = id; + dev->res.start = base; + dev->res.end = base + size - 1; + dev->res.flags = IORESOURCE_MEM; + } + + return dev; +} + diff --git a/include/linux/amba/bus.h b/include/linux/amba/bus.h new file mode 100644 index 0000000..34e6ace --- /dev/null +++ b/include/linux/amba/bus.h @@ -0,0 +1,157 @@ +/* + * linux/include/amba/bus.h + * + * This device type deals with ARM PrimeCells and anything else that + * presents a proper CID (0xB105F00D) at the end of the I/O register + * region or that is derived from a PrimeCell. + * + * Copyright (C) 2003 Deep Blue Solutions Ltd, 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 as + * published by the Free Software Foundation. + */ +#ifndef ASMARM_AMBA_H +#define ASMARM_AMBA_H + +#include <linux/clk.h> +#include <driver.h> +#include <linux/err.h> + +#define AMBA_CID 0xb105f00d + +/** + * struct amba_id - identifies a device on an AMBA bus + * @id: The significant bits if the hardware device ID + * @mask: Bitmask specifying which bits of the id field are significant when + * matching. A driver binds to a device when ((hardware device ID) & mask) + * == id. + * @data: Private data used by the driver. + */ +struct amba_id { + unsigned int id; + unsigned int mask; +#ifndef __KERNEL__ + kernel_ulong_t data; +#else + void *data; +#endif +}; + +struct clk; + +struct amba_device { + struct device_d dev; + struct resource res; + void __iomem *base; + struct clk *pclk; + unsigned int periphid; +}; + +struct amba_driver { + struct driver_d drv; + int (*probe)(struct amba_device *, const struct amba_id *); + int (*remove)(struct amba_device *); + const struct amba_id *id_table; +}; + +enum amba_vendor { + AMBA_VENDOR_ARM = 0x41, + AMBA_VENDOR_ST = 0x80, +}; + +extern struct bus_type amba_bustype; + +#define to_amba_device(d) container_of(d, struct amba_device, dev) + +#define amba_get_drvdata(d) dev_get_drvdata(&d->dev) +#define amba_set_drvdata(d,p) dev_set_drvdata(&d->dev, p) + +int amba_driver_register(struct amba_driver *); +void amba_driver_unregister(struct amba_driver *); +struct amba_device *amba_device_alloc(const char *, int id, resource_size_t, size_t); +void amba_device_put(struct amba_device *); +int amba_device_add(struct amba_device *); +int amba_device_register(struct amba_device *, struct resource *); + +struct amba_device * +amba_aphb_device_add(struct device_d *parent, const char *name, int id, + resource_size_t base, size_t size, + void *pdata, unsigned int periphid); + +static inline struct amba_device * +amba_apb_device_add(struct device_d *parent, const char *name, int id, + resource_size_t base, size_t size, + void *pdata, unsigned int periphid) +{ + return amba_aphb_device_add(parent, name, id, base, size, pdata, + periphid); +} + +static inline struct amba_device * +amba_ahb_device_add(struct device_d *parent, const char *name, int id, + resource_size_t base, size_t size, + void *pdata, unsigned int periphid) +{ + return amba_aphb_device_add(parent, name, id, base, size, pdata, + periphid); +} + + +void amba_device_unregister(struct amba_device *); +struct amba_device *amba_find_device(const char *, struct device_d *, unsigned int, unsigned int); +int amba_request_regions(struct amba_device *, const char *); +void amba_release_regions(struct amba_device *); + +static inline void __iomem *amba_get_mem_region(struct amba_device *dev) +{ + return dev->base; +} + +#define amba_pclk_enable(d) \ + (IS_ERR((d)->pclk) ? 0 : clk_enable((d)->pclk)) + +#define amba_pclk_disable(d) \ + do { if (!IS_ERR((d)->pclk)) clk_disable((d)->pclk); } while (0) + +/* Some drivers don't use the struct amba_device */ +#define AMBA_CONFIG_BITS(a) (((a) >> 24) & 0xff) +#define AMBA_REV_BITS(a) (((a) >> 20) & 0x0f) +#define AMBA_MANF_BITS(a) (((a) >> 12) & 0xff) +#define AMBA_PART_BITS(a) ((a) & 0xfff) + +#define amba_config(d) AMBA_CONFIG_BITS((d)->periphid) +#define amba_rev(d) AMBA_REV_BITS((d)->periphid) +#define amba_manf(d) AMBA_MANF_BITS((d)->periphid) +#define amba_part(d) AMBA_PART_BITS((d)->periphid) + +#define __AMBA_DEV(busid, data) \ + { \ + .init_name = busid, \ + .platform_data = data, \ + } + +/* + * APB devices do not themselves have the ability to address memory, + * so DMA masks should be zero (much like USB peripheral devices.) + * The DMA controller DMA masks should be used instead (much like + * USB host controllers in conventional PCs.) + */ +#define AMBA_APB_DEVICE(name, busid, id, base, data) \ +struct amba_device name##_device = { \ + .dev = __AMBA_DEV(busid, data), \ + .res = DEFINE_RES_MEM(base, SZ_4K), \ + .periphid = id, \ +} + +/* + * AHB devices are DMA capable, so set their DMA masks + */ +#define AMBA_AHB_DEVICE(name, busid, id, base, data) \ +struct amba_device name##_device = { \ + .dev = __AMBA_DEV(busid, data), \ + .res = DEFINE_RES_MEM(base, SZ_4K), \ + .periphid = id, \ +} + +#endif -- 1.7.10.4 _______________________________________________ barebox mailing list [email protected] http://lists.infradead.org/mailman/listinfo/barebox
