xref: /openbmc/linux/include/linux/amba/bus.h (revision ab7f17fb)
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  */
51 struct 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 
62 struct clk;
63 
64 struct 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 
81 struct 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  */
101 enum amba_vendor {
102 	AMBA_VENDOR_ARM = 0x41,
103 	AMBA_VENDOR_ST = 0x80,
104 	AMBA_VENDOR_QCOM = 0x51,
105 	AMBA_VENDOR_LSI = 0xb6,
106 };
107 
108 extern 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 #ifdef CONFIG_ARM_AMBA
116 int amba_driver_register(struct amba_driver *);
117 void amba_driver_unregister(struct amba_driver *);
118 #else
amba_driver_register(struct amba_driver * drv)119 static inline int amba_driver_register(struct amba_driver *drv)
120 {
121 	return -EINVAL;
122 }
amba_driver_unregister(struct amba_driver * drv)123 static inline void amba_driver_unregister(struct amba_driver *drv)
124 {
125 }
126 #endif
127 
128 struct amba_device *amba_device_alloc(const char *, resource_size_t, size_t);
129 void amba_device_put(struct amba_device *);
130 int amba_device_add(struct amba_device *, struct resource *);
131 int amba_device_register(struct amba_device *, struct resource *);
132 void amba_device_unregister(struct amba_device *);
133 int amba_request_regions(struct amba_device *, const char *);
134 void amba_release_regions(struct amba_device *);
135 
136 /* Some drivers don't use the struct amba_device */
137 #define AMBA_CONFIG_BITS(a) (((a) >> 24) & 0xff)
138 #define AMBA_REV_BITS(a) (((a) >> 20) & 0x0f)
139 #define AMBA_MANF_BITS(a) (((a) >> 12) & 0xff)
140 #define AMBA_PART_BITS(a) ((a) & 0xfff)
141 
142 #define amba_config(d)	AMBA_CONFIG_BITS((d)->periphid)
143 #define amba_rev(d)	AMBA_REV_BITS((d)->periphid)
144 #define amba_manf(d)	AMBA_MANF_BITS((d)->periphid)
145 #define amba_part(d)	AMBA_PART_BITS((d)->periphid)
146 
147 #define __AMBA_DEV(busid, data, mask)				\
148 	{							\
149 		.coherent_dma_mask = mask,			\
150 		.init_name = busid,				\
151 		.platform_data = data,				\
152 	}
153 
154 /*
155  * APB devices do not themselves have the ability to address memory,
156  * so DMA masks should be zero (much like USB peripheral devices.)
157  * The DMA controller DMA masks should be used instead (much like
158  * USB host controllers in conventional PCs.)
159  */
160 #define AMBA_APB_DEVICE(name, busid, id, base, irqs, data)	\
161 struct amba_device name##_device = {				\
162 	.dev = __AMBA_DEV(busid, data, 0),			\
163 	.res = DEFINE_RES_MEM(base, SZ_4K),			\
164 	.irq = irqs,						\
165 	.periphid = id,						\
166 }
167 
168 /*
169  * AHB devices are DMA capable, so set their DMA masks
170  */
171 #define AMBA_AHB_DEVICE(name, busid, id, base, irqs, data)	\
172 struct amba_device name##_device = {				\
173 	.dev = __AMBA_DEV(busid, data, ~0ULL),			\
174 	.res = DEFINE_RES_MEM(base, SZ_4K),			\
175 	.irq = irqs,						\
176 	.periphid = id,						\
177 }
178 
179 /*
180  * module_amba_driver() - Helper macro for drivers that don't do anything
181  * special in module init/exit.  This eliminates a lot of boilerplate.  Each
182  * module may only use this macro once, and calling it replaces module_init()
183  * and module_exit()
184  */
185 #define module_amba_driver(__amba_drv) \
186 	module_driver(__amba_drv, amba_driver_register, amba_driver_unregister)
187 
188 /*
189  * builtin_amba_driver() - Helper macro for drivers that don't do anything
190  * special in driver initcall.  This eliminates a lot of boilerplate.  Each
191  * driver may only use this macro once, and calling it replaces the instance
192  * device_initcall().
193  */
194 #define builtin_amba_driver(__amba_drv) \
195 	builtin_driver(__amba_drv, amba_driver_register)
196 
197 #endif
198