1 /* 2 * Copyright (C) 2014 Free Electrons 3 * 4 * License Terms: GNU General Public License v2 5 * Author: Boris BREZILLON <boris.brezillon@free-electrons.com> 6 * 7 * Allwinner A31 APB0 clock gates driver 8 * 9 */ 10 11 #include <linux/clk-provider.h> 12 #include <linux/clkdev.h> 13 #include <linux/module.h> 14 #include <linux/of.h> 15 #include <linux/of_device.h> 16 #include <linux/platform_device.h> 17 18 #define SUN6I_APB0_GATES_MAX_SIZE 32 19 20 struct gates_data { 21 DECLARE_BITMAP(mask, SUN6I_APB0_GATES_MAX_SIZE); 22 }; 23 24 static const struct gates_data sun6i_a31_apb0_gates __initconst = { 25 .mask = {0x7F}, 26 }; 27 28 static const struct gates_data sun8i_a23_apb0_gates __initconst = { 29 .mask = {0x5D}, 30 }; 31 32 static const struct of_device_id sun6i_a31_apb0_gates_clk_dt_ids[] = { 33 { .compatible = "allwinner,sun6i-a31-apb0-gates-clk", .data = &sun6i_a31_apb0_gates }, 34 { .compatible = "allwinner,sun8i-a23-apb0-gates-clk", .data = &sun8i_a23_apb0_gates }, 35 { /* sentinel */ } 36 }; 37 MODULE_DEVICE_TABLE(of, sun6i_a31_apb0_gates_clk_dt_ids); 38 39 static int sun6i_a31_apb0_gates_clk_probe(struct platform_device *pdev) 40 { 41 struct device_node *np = pdev->dev.of_node; 42 struct clk_onecell_data *clk_data; 43 const struct of_device_id *device; 44 const struct gates_data *data; 45 const char *clk_parent; 46 const char *clk_name; 47 struct resource *r; 48 void __iomem *reg; 49 int ngates; 50 int i; 51 int j = 0; 52 53 if (!np) 54 return -ENODEV; 55 56 device = of_match_device(sun6i_a31_apb0_gates_clk_dt_ids, &pdev->dev); 57 if (!device) 58 return -ENODEV; 59 data = device->data; 60 61 r = platform_get_resource(pdev, IORESOURCE_MEM, 0); 62 reg = devm_ioremap_resource(&pdev->dev, r); 63 if (IS_ERR(reg)) 64 return PTR_ERR(reg); 65 66 clk_parent = of_clk_get_parent_name(np, 0); 67 if (!clk_parent) 68 return -EINVAL; 69 70 clk_data = devm_kzalloc(&pdev->dev, sizeof(struct clk_onecell_data), 71 GFP_KERNEL); 72 if (!clk_data) 73 return -ENOMEM; 74 75 /* Worst-case size approximation and memory allocation */ 76 ngates = find_last_bit(data->mask, SUN6I_APB0_GATES_MAX_SIZE); 77 clk_data->clks = devm_kcalloc(&pdev->dev, (ngates + 1), 78 sizeof(struct clk *), GFP_KERNEL); 79 if (!clk_data->clks) 80 return -ENOMEM; 81 82 for_each_set_bit(i, data->mask, SUN6I_APB0_GATES_MAX_SIZE) { 83 of_property_read_string_index(np, "clock-output-names", 84 j, &clk_name); 85 86 clk_data->clks[i] = clk_register_gate(&pdev->dev, clk_name, 87 clk_parent, 0, reg, i, 88 0, NULL); 89 WARN_ON(IS_ERR(clk_data->clks[i])); 90 clk_register_clkdev(clk_data->clks[i], clk_name, NULL); 91 92 j++; 93 } 94 95 clk_data->clk_num = ngates + 1; 96 97 return of_clk_add_provider(np, of_clk_src_onecell_get, clk_data); 98 } 99 100 static struct platform_driver sun6i_a31_apb0_gates_clk_driver = { 101 .driver = { 102 .name = "sun6i-a31-apb0-gates-clk", 103 .of_match_table = sun6i_a31_apb0_gates_clk_dt_ids, 104 }, 105 .probe = sun6i_a31_apb0_gates_clk_probe, 106 }; 107 module_platform_driver(sun6i_a31_apb0_gates_clk_driver); 108 109 MODULE_AUTHOR("Boris BREZILLON <boris.brezillon@free-electrons.com>"); 110 MODULE_DESCRIPTION("Allwinner A31 APB0 gate clocks driver"); 111 MODULE_LICENSE("GPL v2"); 112