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 driver 8 * 9 */ 10 11 #include <linux/clk-provider.h> 12 #include <linux/module.h> 13 #include <linux/of.h> 14 #include <linux/platform_device.h> 15 16 /* 17 * The APB0 clk has a configurable divisor. 18 * 19 * We must use a clk_div_table and not a regular power of 2 20 * divisor here, because the first 2 values divide the clock 21 * by 2. 22 */ 23 static const struct clk_div_table sun6i_a31_apb0_divs[] = { 24 { .val = 0, .div = 2, }, 25 { .val = 1, .div = 2, }, 26 { .val = 2, .div = 4, }, 27 { .val = 3, .div = 8, }, 28 { /* sentinel */ }, 29 }; 30 31 static int sun6i_a31_apb0_clk_probe(struct platform_device *pdev) 32 { 33 struct device_node *np = pdev->dev.of_node; 34 const char *clk_name = np->name; 35 const char *clk_parent; 36 struct resource *r; 37 void __iomem *reg; 38 struct clk *clk; 39 40 r = platform_get_resource(pdev, IORESOURCE_MEM, 0); 41 reg = devm_ioremap_resource(&pdev->dev, r); 42 if (IS_ERR(reg)) 43 return PTR_ERR(reg); 44 45 clk_parent = of_clk_get_parent_name(np, 0); 46 if (!clk_parent) 47 return -EINVAL; 48 49 of_property_read_string(np, "clock-output-names", &clk_name); 50 51 clk = clk_register_divider_table(&pdev->dev, clk_name, clk_parent, 52 0, reg, 0, 2, 0, sun6i_a31_apb0_divs, 53 NULL); 54 if (IS_ERR(clk)) 55 return PTR_ERR(clk); 56 57 return of_clk_add_provider(np, of_clk_src_simple_get, clk); 58 } 59 60 static const struct of_device_id sun6i_a31_apb0_clk_dt_ids[] = { 61 { .compatible = "allwinner,sun6i-a31-apb0-clk" }, 62 { /* sentinel */ } 63 }; 64 65 static struct platform_driver sun6i_a31_apb0_clk_driver = { 66 .driver = { 67 .name = "sun6i-a31-apb0-clk", 68 .of_match_table = sun6i_a31_apb0_clk_dt_ids, 69 }, 70 .probe = sun6i_a31_apb0_clk_probe, 71 }; 72 module_platform_driver(sun6i_a31_apb0_clk_driver); 73 74 MODULE_AUTHOR("Boris BREZILLON <boris.brezillon@free-electrons.com>"); 75 MODULE_DESCRIPTION("Allwinner A31 APB0 clock Driver"); 76 MODULE_LICENSE("GPL v2"); 77