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