1// SPDX-License-Identifier: GPL-2.0
2//
3// rcpm.c - Freescale QorIQ RCPM driver
4//
5// Copyright 2019-2020 NXP
6//
7// Author: Ran Wang <ran.wang_1@nxp.com>
8
9#include <linux/init.h>
10#include <linux/module.h>
11#include <linux/platform_device.h>
12#include <linux/of_address.h>
13#include <linux/slab.h>
14#include <linux/suspend.h>
15#include <linux/kernel.h>
16#include <linux/acpi.h>
17
18#define RCPM_WAKEUP_CELL_MAX_SIZE 7
19
20struct rcpm {
21 unsigned int wakeup_cells;
22 void __iomem *ippdexpcr_base;
23 bool little_endian;
24};
25
26#define SCFG_SPARECR8 0x051c
27
28static void copy_ippdexpcr1_setting(u32 val)
29{
30 struct device_node *np;
31 void __iomem *regs;
32 u32 reg_val;
33
34 np = of_find_compatible_node(NULL, NULL, compat: "fsl,ls1021a-scfg");
35 if (!np)
36 return;
37
38 regs = of_iomap(node: np, index: 0);
39 if (!regs)
40 return;
41
42 reg_val = ioread32be(regs + SCFG_SPARECR8);
43 iowrite32be(val | reg_val, regs + SCFG_SPARECR8);
44
45 iounmap(addr: regs);
46}
47
48/**
49 * rcpm_pm_prepare - performs device-level tasks associated with power
50 * management, such as programming related to the wakeup source control.
51 * @dev: Device to handle.
52 *
53 */
54static int rcpm_pm_prepare(struct device *dev)
55{
56 int i, ret, idx;
57 void __iomem *base;
58 struct wakeup_source *ws;
59 struct rcpm *rcpm;
60 struct device_node *np = dev->of_node;
61 u32 value[RCPM_WAKEUP_CELL_MAX_SIZE + 1];
62 u32 setting[RCPM_WAKEUP_CELL_MAX_SIZE] = {0};
63
64 rcpm = dev_get_drvdata(dev);
65 if (!rcpm)
66 return -EINVAL;
67
68 base = rcpm->ippdexpcr_base;
69 idx = wakeup_sources_read_lock();
70
71 /* Begin with first registered wakeup source */
72 for_each_wakeup_source(ws) {
73
74 /* skip object which is not attached to device */
75 if (!ws->dev || !ws->dev->parent)
76 continue;
77
78 ret = device_property_read_u32_array(dev: ws->dev->parent,
79 propname: "fsl,rcpm-wakeup", val: value,
80 nval: rcpm->wakeup_cells + 1);
81
82 if (ret)
83 continue;
84
85 /*
86 * For DT mode, would handle devices with "fsl,rcpm-wakeup"
87 * pointing to the current RCPM node.
88 *
89 * For ACPI mode, currently we assume there is only one
90 * RCPM controller existing.
91 */
92 if (is_of_node(fwnode: dev->fwnode))
93 if (np->phandle != value[0])
94 continue;
95
96 /* Property "#fsl,rcpm-wakeup-cells" of rcpm node defines the
97 * number of IPPDEXPCR register cells, and "fsl,rcpm-wakeup"
98 * of wakeup source IP contains an integer array: <phandle to
99 * RCPM node, IPPDEXPCR0 setting, IPPDEXPCR1 setting,
100 * IPPDEXPCR2 setting, etc>.
101 *
102 * So we will go thought them to collect setting data.
103 */
104 for (i = 0; i < rcpm->wakeup_cells; i++)
105 setting[i] |= value[i + 1];
106 }
107
108 wakeup_sources_read_unlock(idx);
109
110 /* Program all IPPDEXPCRn once */
111 for (i = 0; i < rcpm->wakeup_cells; i++) {
112 u32 tmp = setting[i];
113 void __iomem *address = base + i * 4;
114
115 if (!tmp)
116 continue;
117
118 /* We can only OR related bits */
119 if (rcpm->little_endian) {
120 tmp |= ioread32(address);
121 iowrite32(tmp, address);
122 } else {
123 tmp |= ioread32be(address);
124 iowrite32be(tmp, address);
125 }
126 /*
127 * Workaround of errata A-008646 on SoC LS1021A:
128 * There is a bug of register ippdexpcr1.
129 * Reading configuration register RCPM_IPPDEXPCR1
130 * always return zero. So save ippdexpcr1's value
131 * to register SCFG_SPARECR8.And the value of
132 * ippdexpcr1 will be read from SCFG_SPARECR8.
133 */
134 if (dev_of_node(dev) && (i == 1))
135 if (of_device_is_compatible(device: np, "fsl,ls1021a-rcpm"))
136 copy_ippdexpcr1_setting(val: tmp);
137 }
138
139 return 0;
140}
141
142static const struct dev_pm_ops rcpm_pm_ops = {
143 .prepare = rcpm_pm_prepare,
144};
145
146static int rcpm_probe(struct platform_device *pdev)
147{
148 struct device *dev = &pdev->dev;
149 struct rcpm *rcpm;
150 int ret;
151
152 rcpm = devm_kzalloc(dev, size: sizeof(*rcpm), GFP_KERNEL);
153 if (!rcpm)
154 return -ENOMEM;
155
156 rcpm->ippdexpcr_base = devm_platform_ioremap_resource(pdev, index: 0);
157 if (IS_ERR(ptr: rcpm->ippdexpcr_base)) {
158 ret = PTR_ERR(ptr: rcpm->ippdexpcr_base);
159 return ret;
160 }
161
162 rcpm->little_endian = device_property_read_bool(
163 dev: &pdev->dev, propname: "little-endian");
164
165 ret = device_property_read_u32(dev: &pdev->dev,
166 propname: "#fsl,rcpm-wakeup-cells", val: &rcpm->wakeup_cells);
167 if (ret)
168 return ret;
169
170 dev_set_drvdata(dev: &pdev->dev, data: rcpm);
171
172 return 0;
173}
174
175static const struct of_device_id rcpm_of_match[] = {
176 { .compatible = "fsl,qoriq-rcpm-2.1+", },
177 {}
178};
179MODULE_DEVICE_TABLE(of, rcpm_of_match);
180
181#ifdef CONFIG_ACPI
182static const struct acpi_device_id rcpm_acpi_ids[] = {
183 {"NXP0015",},
184 { }
185};
186MODULE_DEVICE_TABLE(acpi, rcpm_acpi_ids);
187#endif
188
189static struct platform_driver rcpm_driver = {
190 .driver = {
191 .name = "rcpm",
192 .of_match_table = rcpm_of_match,
193 .acpi_match_table = ACPI_PTR(rcpm_acpi_ids),
194 .pm = &rcpm_pm_ops,
195 },
196 .probe = rcpm_probe,
197};
198
199module_platform_driver(rcpm_driver);
200

source code of linux/drivers/soc/fsl/rcpm.c