diff options
Diffstat (limited to 'drivers/clk/clk-nspire.c')
| -rw-r--r-- | drivers/clk/clk-nspire.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/drivers/clk/clk-nspire.c b/drivers/clk/clk-nspire.c new file mode 100644 index 00000000000..a378db7b238 --- /dev/null +++ b/drivers/clk/clk-nspire.c @@ -0,0 +1,153 @@ +/* + * + * 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); |