xref: /linux/drivers/net/ipa/gsi_reg.c (revision 675f176b4dcc2b75adbcea7ba0e9a649527f53bd)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 /* Copyright (C) 2023 Linaro Ltd. */
4 
5 #include <linux/platform_device.h>
6 #include <linux/io.h>
7 
8 #include "gsi.h"
9 #include "reg.h"
10 #include "gsi_reg.h"
11 
12 /* GSI EE registers as a group are shifted downward by a fixed constant amount
13  * for IPA versions 4.5 and beyond.  This applies to all GSI registers we use
14  * *except* the ones that disable inter-EE interrupts for channels and event
15  * channels.
16  *
17  * The "raw" (not adjusted) GSI register range is mapped, and a pointer to
18  * the mapped range is held in gsi->virt_raw.  The inter-EE interrupt
19  * registers are accessed using that pointer.
20  *
21  * Most registers are accessed using gsi->virt, which is a copy of the "raw"
22  * pointer, adjusted downward by the fixed amount.
23  */
24 #define GSI_EE_REG_ADJUST	0x0000d000			/* IPA v4.5+ */
25 
26 /* Is this register ID valid for the current GSI version? */
27 static bool gsi_reg_id_valid(struct gsi *gsi, enum gsi_reg_id reg_id)
28 {
29 	switch (reg_id) {
30 	case INTER_EE_SRC_CH_IRQ_MSK:
31 	case INTER_EE_SRC_EV_CH_IRQ_MSK:
32 	case CH_C_CNTXT_0:
33 	case CH_C_CNTXT_1:
34 	case CH_C_CNTXT_2:
35 	case CH_C_CNTXT_3:
36 	case CH_C_QOS:
37 	case CH_C_SCRATCH_0:
38 	case CH_C_SCRATCH_1:
39 	case CH_C_SCRATCH_2:
40 	case CH_C_SCRATCH_3:
41 	case EV_CH_E_CNTXT_0:
42 	case EV_CH_E_CNTXT_1:
43 	case EV_CH_E_CNTXT_2:
44 	case EV_CH_E_CNTXT_3:
45 	case EV_CH_E_CNTXT_4:
46 	case EV_CH_E_CNTXT_8:
47 	case EV_CH_E_CNTXT_9:
48 	case EV_CH_E_CNTXT_10:
49 	case EV_CH_E_CNTXT_11:
50 	case EV_CH_E_CNTXT_12:
51 	case EV_CH_E_CNTXT_13:
52 	case EV_CH_E_SCRATCH_0:
53 	case EV_CH_E_SCRATCH_1:
54 	case CH_C_DOORBELL_0:
55 	case EV_CH_E_DOORBELL_0:
56 	case GSI_STATUS:
57 	case CH_CMD:
58 	case EV_CH_CMD:
59 	case GENERIC_CMD:
60 	case HW_PARAM_2:
61 	case CNTXT_TYPE_IRQ:
62 	case CNTXT_TYPE_IRQ_MSK:
63 	case CNTXT_SRC_CH_IRQ:
64 	case CNTXT_SRC_CH_IRQ_MSK:
65 	case CNTXT_SRC_CH_IRQ_CLR:
66 	case CNTXT_SRC_EV_CH_IRQ:
67 	case CNTXT_SRC_EV_CH_IRQ_MSK:
68 	case CNTXT_SRC_EV_CH_IRQ_CLR:
69 	case CNTXT_SRC_IEOB_IRQ:
70 	case CNTXT_SRC_IEOB_IRQ_MSK:
71 	case CNTXT_SRC_IEOB_IRQ_CLR:
72 	case CNTXT_GLOB_IRQ_STTS:
73 	case CNTXT_GLOB_IRQ_EN:
74 	case CNTXT_GLOB_IRQ_CLR:
75 	case CNTXT_GSI_IRQ_STTS:
76 	case CNTXT_GSI_IRQ_EN:
77 	case CNTXT_GSI_IRQ_CLR:
78 	case CNTXT_INTSET:
79 	case ERROR_LOG:
80 	case ERROR_LOG_CLR:
81 	case CNTXT_SCRATCH_0:
82 		return true;
83 
84 	default:
85 		return false;
86 	}
87 }
88 
89 const struct reg *gsi_reg(struct gsi *gsi, enum gsi_reg_id reg_id)
90 {
91 	if (WARN(!gsi_reg_id_valid(gsi, reg_id), "invalid reg %u\n", reg_id))
92 		return NULL;
93 
94 	return reg(gsi->regs, reg_id);
95 }
96 
97 static const struct regs *gsi_regs(struct gsi *gsi)
98 {
99 	switch (gsi->version) {
100 	case IPA_VERSION_3_1:
101 		return &gsi_regs_v3_1;
102 
103 	case IPA_VERSION_3_5_1:
104 		return &gsi_regs_v3_5_1;
105 
106 	case IPA_VERSION_4_2:
107 		return &gsi_regs_v4_0;
108 
109 	case IPA_VERSION_4_5:
110 	case IPA_VERSION_4_7:
111 		return &gsi_regs_v4_5;
112 
113 	case IPA_VERSION_4_9:
114 		return &gsi_regs_v4_9;
115 
116 	case IPA_VERSION_4_11:
117 		return &gsi_regs_v4_11;
118 
119 	default:
120 		return NULL;
121 	}
122 }
123 
124 /* Sets gsi->virt_raw and gsi->virt, and I/O maps the "gsi" memory range */
125 int gsi_reg_init(struct gsi *gsi, struct platform_device *pdev)
126 {
127 	struct device *dev = &pdev->dev;
128 	struct resource *res;
129 	resource_size_t size;
130 	u32 adjust;
131 
132 	/* Get GSI memory range and map it */
133 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "gsi");
134 	if (!res) {
135 		dev_err(dev, "DT error getting \"gsi\" memory property\n");
136 		return -ENODEV;
137 	}
138 
139 	size = resource_size(res);
140 	if (res->start > U32_MAX || size > U32_MAX - res->start) {
141 		dev_err(dev, "DT memory resource \"gsi\" out of range\n");
142 		return -EINVAL;
143 	}
144 
145 	/* Make sure we can make our pointer adjustment if necessary */
146 	adjust = gsi->version < IPA_VERSION_4_5 ? 0 : GSI_EE_REG_ADJUST;
147 	if (res->start < adjust) {
148 		dev_err(dev, "DT memory resource \"gsi\" too low (< %u)\n",
149 			adjust);
150 		return -EINVAL;
151 	}
152 
153 	gsi->regs = gsi_regs(gsi);
154 	if (!gsi->regs) {
155 		dev_err(dev, "unsupported IPA version %u (?)\n", gsi->version);
156 		return -EINVAL;
157 	}
158 
159 	gsi->virt_raw = ioremap(res->start, size);
160 	if (!gsi->virt_raw) {
161 		dev_err(dev, "unable to remap \"gsi\" memory\n");
162 		return -ENOMEM;
163 	}
164 	/* Most registers are accessed using an adjusted register range */
165 	gsi->virt = gsi->virt_raw - adjust;
166 
167 	return 0;
168 }
169 
170 /* Inverse of gsi_reg_init() */
171 void gsi_reg_exit(struct gsi *gsi)
172 {
173 	gsi->virt = NULL;
174 	iounmap(gsi->virt_raw);
175 	gsi->virt_raw = NULL;
176 }
177