bus.h

  1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 *  linux/include/amba/bus.h
  4 *
  5 *  This device type deals with ARM PrimeCells and anything else that
  6 *  presents a proper CID (0xB105F00D) at the end of the I/O register
  7 *  region or that is derived from a PrimeCell.
  8 *
  9 *  Copyright (C) 2003 Deep Blue Solutions Ltd, All Rights Reserved.
 10 */
 11#ifndef ASMARM_AMBA_H
 12#define ASMARM_AMBA_H
 13
 14#include <linux/clk.h>
 15#include <linux/device.h>
 16#include <linux/mod_devicetable.h>
 17#include <linux/err.h>
 18#include <linux/resource.h>
 19#include <linux/regulator/consumer.h>
 20
 21#define AMBA_NR_IRQS	9
 22#define AMBA_CID	0xb105f00d
 23#define CORESIGHT_CID	0xb105900d
 24
 25/*
 26 * CoreSight Architecture specification updates the ID specification
 27 * for components on the AMBA bus. (ARM IHI 0029E)
 28 *
 29 * Bits 15:12 of the CID are the device class.
 30 *
 31 * Class 0xF remains for PrimeCell and legacy components. (AMBA_CID above)
 32 * Class 0x9 defines the component as CoreSight (CORESIGHT_CID above)
 33 * Class 0x0, 0x1, 0xB, 0xE define components that do not have driver support
 34 * at present.
 35 * Class 0x2-0x8,0xA and 0xD-0xD are presently reserved.
 36 *
 37 * Remaining CID bits stay as 0xb105-00d
 38 */
 39
 40/**
 41 * Class 0x9 components use additional values to form a Unique Component
 42 * Identifier (UCI), where peripheral ID values are identical for different
 43 * components. Passed to the amba bus code from the component driver via
 44 * the amba_id->data pointer.
 45 * @devarch	: coresight devarch register value
 46 * @devarch_mask: mask bits used for matching. 0 indicates UCI not used.
 47 * @devtype	: coresight device type value
 48 * @data	: additional driver data. As we have usurped the original
 49 *		pointer some devices may still need additional data
 50 */
 51struct amba_cs_uci_id {
 52	unsigned int devarch;
 53	unsigned int devarch_mask;
 54	unsigned int devtype;
 55	void *data;
 56};
 57
 58/* define offsets for registers used by UCI */
 59#define UCI_REG_DEVTYPE_OFFSET	0xFCC
 60#define UCI_REG_DEVARCH_OFFSET	0xFBC
 61
 62struct clk;
 63
 64struct amba_device {
 65	struct device		dev;
 66	struct resource		res;
 67	struct clk		*pclk;
 68	struct device_dma_parameters dma_parms;
 69	unsigned int		periphid;
 70	struct mutex		periphid_lock;
 71	unsigned int		cid;
 72	struct amba_cs_uci_id	uci;
 73	unsigned int		irq[AMBA_NR_IRQS];
 74	/*
 75	 * Driver name to force a match.  Do not set directly, because core
 76	 * frees it.  Use driver_set_override() to set or clear it.
 77	 */
 78	const char		*driver_override;
 79};
 80
 81struct amba_driver {
 82	struct device_driver	drv;
 83	int			(*probe)(struct amba_device *, const struct amba_id *);
 84	void			(*remove)(struct amba_device *);
 85	void			(*shutdown)(struct amba_device *);
 86	const struct amba_id	*id_table;
 87	/*
 88	 * For most device drivers, no need to care about this flag as long as
 89	 * all DMAs are handled through the kernel DMA API. For some special
 90	 * ones, for example VFIO drivers, they know how to manage the DMA
 91	 * themselves and set this flag so that the IOMMU layer will allow them
 92	 * to setup and manage their own I/O address space.
 93	 */
 94	bool driver_managed_dma;
 95};
 96
 97/*
 98 * Constants for the designer field of the Peripheral ID register. When bit 7
 99 * is set to '1', bits [6:0] should be the JEP106 manufacturer identity code.
100 */
101enum amba_vendor {
102	AMBA_VENDOR_ARM = 0x41,
103	AMBA_VENDOR_ST = 0x80,
104	AMBA_VENDOR_QCOM = 0x51,
105	AMBA_VENDOR_LSI = 0xb6,
106};
107
108extern const struct bus_type amba_bustype;
109
110#define to_amba_device(d)	container_of_const(d, struct amba_device, dev)
111
112#define amba_get_drvdata(d)	dev_get_drvdata(&d->dev)
113#define amba_set_drvdata(d,p)	dev_set_drvdata(&d->dev, p)
114
115/*
116 * use a macro to avoid include chaining to get THIS_MODULE
117 */
118#define amba_driver_register(drv) \
119	__amba_driver_register(drv, THIS_MODULE)
120
121#ifdef CONFIG_ARM_AMBA
122int __amba_driver_register(struct amba_driver *, struct module *);
123void amba_driver_unregister(struct amba_driver *);
124bool dev_is_amba(const struct device *dev);
125#else
126static inline int __amba_driver_register(struct amba_driver *drv,
127					 struct module *owner)
128{
129	return -EINVAL;
130}
131static inline void amba_driver_unregister(struct amba_driver *drv)
132{
133}
134static inline bool dev_is_amba(const struct device *dev)
135{
136	return false;
137}
138#endif
139
140struct amba_device *amba_device_alloc(const char *, resource_size_t, size_t);
141void amba_device_put(struct amba_device *);
142int amba_device_add(struct amba_device *, struct resource *);
143int amba_device_register(struct amba_device *, struct resource *);
144void amba_device_unregister(struct amba_device *);
145int amba_request_regions(struct amba_device *, const char *);
146void amba_release_regions(struct amba_device *);
147
148/* Some drivers don't use the struct amba_device */
149#define AMBA_CONFIG_BITS(a) (((a) >> 24) & 0xff)
150#define AMBA_REV_BITS(a) (((a) >> 20) & 0x0f)
151#define AMBA_MANF_BITS(a) (((a) >> 12) & 0xff)
152#define AMBA_PART_BITS(a) ((a) & 0xfff)
153
154#define amba_config(d)	AMBA_CONFIG_BITS((d)->periphid)
155#define amba_rev(d)	AMBA_REV_BITS((d)->periphid)
156#define amba_manf(d)	AMBA_MANF_BITS((d)->periphid)
157#define amba_part(d)	AMBA_PART_BITS((d)->periphid)
158
159#define __AMBA_DEV(busid, data, mask)				\
160	{							\
161		.coherent_dma_mask = mask,			\
162		.init_name = busid,				\
163		.platform_data = data,				\
164	}
165
166/*
167 * APB devices do not themselves have the ability to address memory,
168 * so DMA masks should be zero (much like USB peripheral devices.)
169 * The DMA controller DMA masks should be used instead (much like
170 * USB host controllers in conventional PCs.)
171 */
172#define AMBA_APB_DEVICE(name, busid, id, base, irqs, data)	\
173struct amba_device name##_device = {				\
174	.dev = __AMBA_DEV(busid, data, 0),			\
175	.res = DEFINE_RES_MEM(base, SZ_4K),			\
176	.irq = irqs,						\
177	.periphid = id,						\
178}
179
180/*
181 * AHB devices are DMA capable, so set their DMA masks
182 */
183#define AMBA_AHB_DEVICE(name, busid, id, base, irqs, data)	\
184struct amba_device name##_device = {				\
185	.dev = __AMBA_DEV(busid, data, ~0ULL),			\
186	.res = DEFINE_RES_MEM(base, SZ_4K),			\
187	.irq = irqs,						\
188	.periphid = id,						\
189}
190
191/*
192 * module_amba_driver() - Helper macro for drivers that don't do anything
193 * special in module init/exit.  This eliminates a lot of boilerplate.  Each
194 * module may only use this macro once, and calling it replaces module_init()
195 * and module_exit()
196 */
197#define module_amba_driver(__amba_drv) \
198	module_driver(__amba_drv, amba_driver_register, amba_driver_unregister)
199
200/*
201 * builtin_amba_driver() - Helper macro for drivers that don't do anything
202 * special in driver initcall.  This eliminates a lot of boilerplate.  Each
203 * driver may only use this macro once, and calling it replaces the instance
204 * device_initcall().
205 */
206#define builtin_amba_driver(__amba_drv) \
207	builtin_driver(__amba_drv, amba_driver_register)
208
209#endif