/* * * Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2, as * published by the Free Software Foundation. * */ #include <linux/clk-provider.h> #include <linux/err.h> #include <linux/io.h> #include <linux/of.h> #include <linux/of_address.h> #define MHZ (1000 * 1000) #define BASE_CPU_SHIFT 1 #define BASE_CPU_MASK 0x7F #define CPU_AHB_SHIFT 12 #define CPU_AHB_MASK 0x07 #define FIXED_BASE_SHIFT 8 #define FIXED_BASE_MASK 0x01 #define CLASSIC_BASE_SHIFT 16 #define CLASSIC_BASE_MASK 0x1F #define CX_BASE_SHIFT 15 #define CX_BASE_MASK 0x3F #define CX_UNKNOWN_SHIFT 21 #define CX_UNKNOWN_MASK 0x03 struct nspire_clk_info { u32 base_clock; u16 base_cpu_ratio; u16 base_ahb_ratio; }; #define EXTRACT(var, prop) (((var)>>prop##_SHIFT) & prop##_MASK) static void nspire_clkinfo_cx(u32 val, struct nspire_clk_info *clk) { if (EXTRACT(val, FIXED_BASE)) clk->base_clock = 48 * MHZ; else clk->base_clock = 6 * EXTRACT(val, CX_BASE) * MHZ; clk->base_cpu_ratio = EXTRACT(val, BASE_CPU) * EXTRACT(val, CX_UNKNOWN); clk->base_ahb_ratio = clk->base_cpu_ratio * (EXTRACT(val, CPU_AHB) + 1); } static void nspire_clkinfo_classic(u32 val, struct nspire_clk_info *clk) { if (EXTRACT(val, FIXED_BASE)) clk->base_clock = 27 * MHZ; else clk->base_clock = (300 - 6 * EXTRACT(val, CLASSIC_BASE)) * MHZ; clk->base_cpu_ratio = EXTRACT(val, BASE_CPU) * 2; clk->base_ahb_ratio = clk->base_cpu_ratio * (EXTRACT(val, CPU_AHB) + 1); } static void __init nspire_ahbdiv_setup(struct device_node *node, void (*get_clkinfo)(u32, struct nspire_clk_info *)) { u32 val; void __iomem *io; struct clk *clk; const char *clk_name = node->name; const char *parent_name; struct nspire_clk_info info; io = of_iomap(node, 0); if (!io) return; val = readl(io); iounmap(io); get_clkinfo(val, &info); of_property_read_string(node, "clock-output-names", &clk_name); parent_name = of_clk_get_parent_name(node, 0); clk = clk_register_fixed_factor(NULL, clk_name, parent_name, 0, 1, info.base_ahb_ratio); if (!IS_ERR(clk)) of_clk_add_provider(node, of_clk_src_simple_get, clk); } static void __init nspire_ahbdiv_setup_cx(struct device_node *node) { nspire_ahbdiv_setup(node, nspire_clkinfo_cx); } static void __init nspire_ahbdiv_setup_classic(struct device_node *node) { nspire_ahbdiv_setup(node, nspire_clkinfo_classic); } CLK_OF_DECLARE(nspire_ahbdiv_cx, "lsi,nspire-cx-ahb-divider", nspire_ahbdiv_setup_cx); CLK_OF_DECLARE(nspire_ahbdiv_classic, "lsi,nspire-classic-ahb-divider", nspire_ahbdiv_setup_classic); static void __init nspire_clk_setup(struct device_node *node, void (*get_clkinfo)(u32, struct nspire_clk_info *)) { u32 val; void __iomem *io; struct clk *clk; const char *clk_name = node->name; struct nspire_clk_info info; io = of_iomap(node, 0); if (!io) return; val = readl(io); iounmap(io); get_clkinfo(val, &info); of_property_read_string(node, "clock-output-names", &clk_name); clk = clk_register_fixed_rate(NULL, clk_name, NULL, CLK_IS_ROOT, info.base_clock); if (!IS_ERR(clk)) of_clk_add_provider(node, of_clk_src_simple_get, clk); else return; pr_info("TI-NSPIRE Base: %uMHz CPU: %uMHz AHB: %uMHz\n", info.base_clock / MHZ, info.base_clock / info.base_cpu_ratio / MHZ, info.base_clock / info.base_ahb_ratio / MHZ); } static void __init nspire_clk_setup_cx(struct device_node *node) { nspire_clk_setup(node, nspire_clkinfo_cx); } static void __init nspire_clk_setup_classic(struct device_node *node) { nspire_clk_setup(node, nspire_clkinfo_classic); } CLK_OF_DECLARE(nspire_clk_cx, "lsi,nspire-cx-clock", nspire_clk_setup_cx); CLK_OF_DECLARE(nspire_clk_classic, "lsi,nspire-classic-clock", nspire_clk_setup_classic);