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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * ARM Integrator Logical Module bus driver4 * Copyright (C) 2020 Linaro Ltd.5 * Author: Linus Walleij <linus.walleij@linaro.org>6 *7 * See the device tree bindings for this block for more details on the8 * hardware.9 */10 11#include <linux/module.h>12#include <linux/err.h>13#include <linux/io.h>14#include <linux/of.h>15#include <linux/of_address.h>16#include <linux/of_platform.h>17#include <linux/init.h>18#include <linux/slab.h>19#include <linux/platform_device.h>20#include <linux/bitops.h>21#include <linux/mfd/syscon.h>22#include <linux/regmap.h>23 24/* All information about the connected logic modules are in here */25#define INTEGRATOR_SC_DEC_OFFSET 0x1026 27/* Base address for the expansion modules */28#define INTEGRATOR_AP_EXP_BASE 0xc000000029#define INTEGRATOR_AP_EXP_STRIDE 0x1000000030 31static int integrator_lm_populate(int num, struct device *dev)32{33 struct device_node *np = dev->of_node;34 struct device_node *child;35 u32 base;36 int ret;37 38 base = INTEGRATOR_AP_EXP_BASE + (num * INTEGRATOR_AP_EXP_STRIDE);39 40 /* Walk over the child nodes and see what chipselects we use */41 for_each_available_child_of_node(np, child) {42 struct resource res;43 44 ret = of_address_to_resource(child, 0, &res);45 if (ret) {46 dev_info(dev, "no valid address on child\n");47 continue;48 }49 50 /* First populate the syscon then any devices */51 if (res.start == base) {52 dev_info(dev, "populate module @0x%08x from DT\n",53 base);54 ret = of_platform_default_populate(child, NULL, dev);55 if (ret) {56 dev_err(dev, "failed to populate module\n");57 of_node_put(child);58 return ret;59 }60 }61 }62 63 return 0;64}65 66static const struct of_device_id integrator_ap_syscon_match[] = {67 { .compatible = "arm,integrator-ap-syscon"},68 { },69};70 71static int integrator_ap_lm_probe(struct platform_device *pdev)72{73 struct device *dev = &pdev->dev;74 struct device_node *syscon;75 static struct regmap *map;76 u32 val;77 int ret;78 int i;79 80 /* Look up the system controller */81 syscon = of_find_matching_node(NULL, integrator_ap_syscon_match);82 if (!syscon) {83 dev_err(dev,84 "could not find Integrator/AP system controller\n");85 return -ENODEV;86 }87 map = syscon_node_to_regmap(syscon);88 of_node_put(syscon);89 if (IS_ERR(map)) {90 dev_err(dev,91 "could not find Integrator/AP system controller\n");92 return PTR_ERR(map);93 }94 95 ret = regmap_read(map, INTEGRATOR_SC_DEC_OFFSET, &val);96 if (ret) {97 dev_err(dev, "could not read from Integrator/AP syscon\n");98 return ret;99 }100 101 /* Loop over the connected modules */102 for (i = 0; i < 4; i++) {103 if (!(val & BIT(4 + i)))104 continue;105 106 dev_info(dev, "detected module in slot %d\n", i);107 ret = integrator_lm_populate(i, dev);108 if (ret)109 return ret;110 }111 112 return 0;113}114 115static const struct of_device_id integrator_ap_lm_match[] = {116 { .compatible = "arm,integrator-ap-lm"},117 { },118};119 120static struct platform_driver integrator_ap_lm_driver = {121 .probe = integrator_ap_lm_probe,122 .driver = {123 .name = "integratorap-lm",124 .of_match_table = integrator_ap_lm_match,125 },126};127module_platform_driver(integrator_ap_lm_driver);128MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");129MODULE_DESCRIPTION("Integrator AP Logical Module driver");130