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 static struct clk *out[2];
   8 static struct clk_onecell_data clk_data = { out, 2 };
   9
  10 #define SYSCLK_CTRL     0x20
  11 #define CPUCLK_CTRL     0x24
  12 #define LEGACY_DIV      0x3c
  13
  14 #define PLL_N(val)      (((val) >>  0) & 0x7f)
  15 #define PLL_K(val)      (((val) >> 13) & 0x7)
  16 #define PLL_M(val)      (((val) >> 16) & 0x7)
  17 #define DIV_INDEX(val)  (((val) >>  8) & 0xf)
  18
  19 static void __init make_pll(int idx, const char *parent, void __iomem *base)
  20 {
  21         char name[8];
  22         u32 val, mul, div;
  23
  24         sprintf(name, "pll%d", idx);
  25         val = readl_relaxed(base + idx*8);
  26         mul =  PLL_N(val) + 1;
  27         div = (PLL_M(val) + 1) << PLL_K(val);
  28         clk_register_fixed_factor(NULL, name, parent, 0, mul, div);
  29 }
  30
  31 static int __init get_div(void __iomem *base)
  32 {
  33         u8 sysclk_tab[16] = { 2, 4, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4 };
  34         int idx = DIV_INDEX(readl_relaxed(base + LEGACY_DIV));
  35
  36         return sysclk_tab[idx];
  37 }
  38
  39 static void __init tango4_clkgen_setup(struct device_node *np)
  40 {
  41         int div, ret;
  42         void __iomem *base = of_iomap(np, 0);
  43         const char *parent = of_clk_get_parent_name(np, 0);
  44
  45         if (!base)
  46                 panic("%s: invalid address\n", np->full_name);
  47
  48         make_pll(0, parent, base);
  49         make_pll(1, parent, base);
  50
  51         out[0] = clk_register_divider(NULL, "cpuclk", "pll0", 0,
  52                         base + CPUCLK_CTRL, 8, 8, CLK_DIVIDER_ONE_BASED, NULL);
  53
  54         div = readl_relaxed(base + SYSCLK_CTRL) & BIT(23) ? get_div(base) : 4;
  55         out[1] = clk_register_fixed_factor(NULL, "sysclk", "pll1", 0, 1, div);
  56
  57         ret = of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
  58         if (IS_ERR(out[0]) || IS_ERR(out[1]) || ret < 0)
  59                 panic("%s: clk registration failed\n", np->full_name);
  60 }
  61 CLK_OF_DECLARE(tango4_clkgen, "sigma,tango4-clkgen", tango4_clkgen_setup);