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| 1 | +/* |
| 2 | + * ID and revision information for mvebu SoCs |
| 3 | + * |
| 4 | + * Copyright (C) 2014 Marvell |
| 5 | + * |
| 6 | + * Gregory CLEMENT <gregory.clement@free-electrons.com> |
| 7 | + * |
| 8 | + * This file is licensed under the terms of the GNU General Public |
| 9 | + * License version 2. This program is licensed "as is" without any |
| 10 | + * warranty of any kind, whether express or implied. |
| 11 | + * |
| 12 | + * All the mvebu SoCs have information related to their variant and |
| 13 | + * revision that can be read from the PCI control register. This is |
| 14 | + * done before the PCI initialization to avoid any conflict. Once the |
| 15 | + * ID and revision are retrieved, the mapping is freed. |
| 16 | + */ |
| 17 | + |
| 18 | +#define pr_fmt(fmt) "mvebu-soc-id: " fmt |
| 19 | + |
| 20 | +#include <linux/clk.h> |
| 21 | +#include <linux/init.h> |
| 22 | +#include <linux/io.h> |
| 23 | +#include <linux/kernel.h> |
| 24 | +#include <linux/of.h> |
| 25 | +#include <linux/of_address.h> |
| 26 | +#include "mvebu-soc-id.h" |
| 27 | + |
| 28 | +#define PCIE_DEV_ID_OFF 0x0 |
| 29 | +#define PCIE_DEV_REV_OFF 0x8 |
| 30 | + |
| 31 | +#define SOC_ID_MASK 0xFFFF0000 |
| 32 | +#define SOC_REV_MASK 0xFF |
| 33 | + |
| 34 | +static u32 soc_dev_id; |
| 35 | +static u32 soc_rev; |
| 36 | +static bool is_id_valid; |
| 37 | + |
| 38 | +static const struct of_device_id mvebu_pcie_of_match_table[] = { |
| 39 | + { .compatible = "marvell,armada-xp-pcie", }, |
| 40 | + { .compatible = "marvell,armada-370-pcie", }, |
| 41 | + {}, |
| 42 | +}; |
| 43 | + |
| 44 | +int mvebu_get_soc_id(u32 *dev, u32 *rev) |
| 45 | +{ |
| 46 | + if (is_id_valid) { |
| 47 | + *dev = soc_dev_id; |
| 48 | + *rev = soc_rev; |
| 49 | + return 0; |
| 50 | + } else |
| 51 | + return -1; |
| 52 | +} |
| 53 | + |
| 54 | +static int __init mvebu_soc_id_init(void) |
| 55 | +{ |
| 56 | + struct device_node *np; |
| 57 | + int ret = 0; |
| 58 | + void __iomem *pci_base; |
| 59 | + struct clk *clk; |
| 60 | + struct device_node *child; |
| 61 | + |
| 62 | + np = of_find_matching_node(NULL, mvebu_pcie_of_match_table); |
| 63 | + if (!np) |
| 64 | + return ret; |
| 65 | + |
| 66 | + /* |
| 67 | + * ID and revision are available from any port, so we |
| 68 | + * just pick the first one |
| 69 | + */ |
| 70 | + child = of_get_next_child(np, NULL); |
| 71 | + if (child == NULL) { |
| 72 | + pr_err("cannot get pci node\n"); |
| 73 | + ret = -ENOMEM; |
| 74 | + goto clk_err; |
| 75 | + } |
| 76 | + |
| 77 | + clk = of_clk_get_by_name(child, NULL); |
| 78 | + if (IS_ERR(clk)) { |
| 79 | + pr_err("cannot get clock\n"); |
| 80 | + ret = -ENOMEM; |
| 81 | + goto clk_err; |
| 82 | + } |
| 83 | + |
| 84 | + ret = clk_prepare_enable(clk); |
| 85 | + if (ret) { |
| 86 | + pr_err("cannot enable clock\n"); |
| 87 | + goto clk_err; |
| 88 | + } |
| 89 | + |
| 90 | + pci_base = of_iomap(child, 0); |
| 91 | + if (IS_ERR(pci_base)) { |
| 92 | + pr_err("cannot map registers\n"); |
| 93 | + ret = -ENOMEM; |
| 94 | + goto res_ioremap; |
| 95 | + } |
| 96 | + |
| 97 | + /* SoC ID */ |
| 98 | + soc_dev_id = readl(pci_base + PCIE_DEV_ID_OFF) >> 16; |
| 99 | + |
| 100 | + /* SoC revision */ |
| 101 | + soc_rev = readl(pci_base + PCIE_DEV_REV_OFF) & SOC_REV_MASK; |
| 102 | + |
| 103 | + is_id_valid = true; |
| 104 | + |
| 105 | + pr_info("MVEBU SoC ID=0x%X, Rev=0x%X\n", soc_dev_id, soc_rev); |
| 106 | + |
| 107 | + iounmap(pci_base); |
| 108 | + |
| 109 | +res_ioremap: |
| 110 | + clk_disable_unprepare(clk); |
| 111 | + |
| 112 | +clk_err: |
| 113 | + of_node_put(child); |
| 114 | + of_node_put(np); |
| 115 | + |
| 116 | + return ret; |
| 117 | +} |
| 118 | +core_initcall(mvebu_soc_id_init); |
| 119 | + |
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