LXR linux/drivers/clk/clk-tango4.c

   1#include <linux/kernel.h>
   2#include <linux/clk-provider.h>
   3#include <linux/of_address.h>
   4#include <linux/init.h>
   5#include <linux/io.h>
   6
   7#define CLK_COUNT 4 /* cpu_clk, sys_clk, usb_clk, sdio_clk */
   8static struct clk *clks[CLK_COUNT];
   9static struct clk_onecell_data clk_data = { clks, CLK_COUNT };
  10
  11#define SYSCLK_DIV      0x20
  12#define CPUCLK_DIV      0x24
  13#define DIV_BYPASS      BIT(23)
  14
  15/*** CLKGEN_PLL ***/
  16#define extract_pll_n(val)      ((val >>  0) & ((1u << 7) - 1))
  17#define extract_pll_k(val)      ((val >> 13) & ((1u << 3) - 1))
  18#define extract_pll_m(val)      ((val >> 16) & ((1u << 3) - 1))
  19#define extract_pll_isel(val)   ((val >> 24) & ((1u << 3) - 1))
  20
  21static void __init make_pll(int idx, const char *parent, void __iomem *base)
  22{
  23        char name[8];
  24        u32 val, mul, div;
  25
  26        sprintf(name, "pll%d", idx);
  27        val = readl(base + idx * 8);
  28        mul =  extract_pll_n(val) + 1;
  29        div = (extract_pll_m(val) + 1) << extract_pll_k(val);
  30        clk_register_fixed_factor(NULL, name, parent, 0, mul, div);
  31        if (extract_pll_isel(val) != 1)
  32                panic("%s: input not set to XTAL_IN\n", name);
  33}
  34
  35static void __init make_cd(int idx, void __iomem *base)
  36{
  37        char name[8];
  38        u32 val, mul, div;
  39
  40        sprintf(name, "cd%d", idx);
  41        val = readl(base + idx * 8);
  42        mul =  1 << 27;
  43        div = (2 << 27) + val;
  44        clk_register_fixed_factor(NULL, name, "pll2", 0, mul, div);
  45        if (val > 0xf0000000)
  46                panic("%s: unsupported divider %x\n", name, val);
  47}
  48
  49static void __init tango4_clkgen_setup(struct device_node *np)
  50{
  51        struct clk **pp = clk_data.clks;
  52        void __iomem *base = of_iomap(np, 0);
  53        const char *parent = of_clk_get_parent_name(np, 0);
  54
  55        if (!base)
  56                panic("%s: invalid address\n", np->name);
  57
  58        if (readl(base + CPUCLK_DIV) & DIV_BYPASS)
  59                panic("%s: unsupported cpuclk setup\n", np->name);
  60
  61        if (readl(base + SYSCLK_DIV) & DIV_BYPASS)
  62                panic("%s: unsupported sysclk setup\n", np->name);
  63
  64        writel(0x100, base + CPUCLK_DIV); /* disable frequency ramping */
  65
  66        make_pll(0, parent, base);
  67        make_pll(1, parent, base);
  68        make_pll(2, parent, base);
  69        make_cd(2, base + 0x80);
  70        make_cd(6, base + 0x80);
  71
  72        pp[0] = clk_register_divider(NULL, "cpu_clk", "pll0", 0,
  73                        base + CPUCLK_DIV, 8, 8, CLK_DIVIDER_ONE_BASED, NULL);
  74        pp[1] = clk_register_fixed_factor(NULL, "sys_clk", "pll1", 0, 1, 4);
  75        pp[2] = clk_register_fixed_factor(NULL,  "usb_clk", "cd2", 0, 1, 2);
  76        pp[3] = clk_register_fixed_factor(NULL, "sdio_clk", "cd6", 0, 1, 2);
  77
  78        if (IS_ERR(pp[0]) || IS_ERR(pp[1]) || IS_ERR(pp[2]) || IS_ERR(pp[3]))
  79                panic("%s: clk registration failed\n", np->name);
  80
  81        if (of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data))
  82                panic("%s: clk provider registration failed\n", np->name);
  83}
  84CLK_OF_DECLARE(tango4_clkgen, "sigma,tango4-clkgen", tango4_clkgen_setup);
  85