// SPDX-License-Identifier: GPL-2.0-only /* * ARM Integrator Logical Module bus driver * Copyright (C) 2020 Linaro Ltd. * Author: Linus Walleij <linus.walleij@linaro.org> * * See the device tree bindings for this block for more details on the * hardware. */ #include <linux/module.h> #include <linux/err.h> #include <linux/io.h> #include <linux/of.h> #include <linux/of_address.h> #include <linux/of_platform.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/platform_device.h> #include <linux/bitops.h> #include <linux/mfd/syscon.h> #include <linux/regmap.h> /* All information about the connected logic modules are in here */ #define INTEGRATOR_SC_DEC_OFFSET 0x10 /* Base address for the expansion modules */ #define INTEGRATOR_AP_EXP_BASE 0xc0000000 #define INTEGRATOR_AP_EXP_STRIDE 0x10000000 static int integrator_lm_populate(int num, struct device *dev) { struct device_node *np = dev->of_node; struct device_node *child; u32 base; int ret; base = INTEGRATOR_AP_EXP_BASE + (num * INTEGRATOR_AP_EXP_STRIDE); /* Walk over the child nodes and see what chipselects we use */ for_each_available_child_of_node(np, child) { struct resource res; ret = of_address_to_resource(child, 0, &res); if (ret) { dev_info(dev, "no valid address on child\n"); continue; } /* First populate the syscon then any devices */ if (res.start == base) { dev_info(dev, "populate module @0x%08x from DT\n", base); ret = of_platform_default_populate(child, NULL, dev); if (ret) { dev_err(dev, "failed to populate module\n"); of_node_put(child); return ret; } } } return 0; } static const struct of_device_id integrator_ap_syscon_match[] = { { .compatible = "arm,integrator-ap-syscon"}, { }, }; static int integrator_ap_lm_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct device_node *syscon; static struct regmap *map; u32 val; int ret; int i; /* Look up the system controller */ syscon = of_find_matching_node(NULL, integrator_ap_syscon_match); if (!syscon) { dev_err(dev, "could not find Integrator/AP system controller\n"); return -ENODEV; } map = syscon_node_to_regmap(syscon); if (IS_ERR(map)) { dev_err(dev, "could not find Integrator/AP system controller\n"); return PTR_ERR(map); } ret = regmap_read(map, INTEGRATOR_SC_DEC_OFFSET, &val); if (ret) { dev_err(dev, "could not read from Integrator/AP syscon\n"); return ret; } /* Loop over the connected modules */ for (i = 0; i < 4; i++) { if (!(val & BIT(4 + i))) continue; dev_info(dev, "detected module in slot %d\n", i); ret = integrator_lm_populate(i, dev); if (ret) return ret; } return 0; } static const struct of_device_id integrator_ap_lm_match[] = { { .compatible = "arm,integrator-ap-lm"}, { }, }; static struct platform_driver integrator_ap_lm_driver = { .probe = integrator_ap_lm_probe, .driver = { .name = "integratorap-lm", .of_match_table = integrator_ap_lm_match, }, }; module_platform_driver(integrator_ap_lm_driver); MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>"); MODULE_DESCRIPTION("Integrator AP Logical Module driver"); MODULE_LICENSE("GPL v2");