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linux-next/drivers/clk/clk-tango4.c
Marc Gonzalez fefe0535b7 clk: tango4: improve clkgen driver
Add support for USB and SDIO clocks.
Report unsupported setups and panic.

Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-04-15 17:16:06 -07:00

85 lines
2.6 KiB
C

#include <linux/kernel.h>
#include <linux/clk-provider.h>
#include <linux/of_address.h>
#include <linux/init.h>
#include <linux/io.h>
#define CLK_COUNT 4 /* cpu_clk, sys_clk, usb_clk, sdio_clk */
static struct clk *clks[CLK_COUNT];
static struct clk_onecell_data clk_data = { clks, CLK_COUNT };
#define SYSCLK_DIV 0x20
#define CPUCLK_DIV 0x24
#define DIV_BYPASS BIT(23)
/*** CLKGEN_PLL ***/
#define extract_pll_n(val) ((val >> 0) & ((1u << 7) - 1))
#define extract_pll_k(val) ((val >> 13) & ((1u << 3) - 1))
#define extract_pll_m(val) ((val >> 16) & ((1u << 3) - 1))
#define extract_pll_isel(val) ((val >> 24) & ((1u << 3) - 1))
static void __init make_pll(int idx, const char *parent, void __iomem *base)
{
char name[8];
u32 val, mul, div;
sprintf(name, "pll%d", idx);
val = readl(base + idx * 8);
mul = extract_pll_n(val) + 1;
div = (extract_pll_m(val) + 1) << extract_pll_k(val);
clk_register_fixed_factor(NULL, name, parent, 0, mul, div);
if (extract_pll_isel(val) != 1)
panic("%s: input not set to XTAL_IN\n", name);
}
static void __init make_cd(int idx, void __iomem *base)
{
char name[8];
u32 val, mul, div;
sprintf(name, "cd%d", idx);
val = readl(base + idx * 8);
mul = 1 << 27;
div = (2 << 27) + val;
clk_register_fixed_factor(NULL, name, "pll2", 0, mul, div);
if (val > 0xf0000000)
panic("%s: unsupported divider %x\n", name, val);
}
static void __init tango4_clkgen_setup(struct device_node *np)
{
struct clk **pp = clk_data.clks;
void __iomem *base = of_iomap(np, 0);
const char *parent = of_clk_get_parent_name(np, 0);
if (!base)
panic("%s: invalid address\n", np->name);
if (readl(base + CPUCLK_DIV) & DIV_BYPASS)
panic("%s: unsupported cpuclk setup\n", np->name);
if (readl(base + SYSCLK_DIV) & DIV_BYPASS)
panic("%s: unsupported sysclk setup\n", np->name);
writel(0x100, base + CPUCLK_DIV); /* disable frequency ramping */
make_pll(0, parent, base);
make_pll(1, parent, base);
make_pll(2, parent, base);
make_cd(2, base + 0x80);
make_cd(6, base + 0x80);
pp[0] = clk_register_divider(NULL, "cpu_clk", "pll0", 0,
base + CPUCLK_DIV, 8, 8, CLK_DIVIDER_ONE_BASED, NULL);
pp[1] = clk_register_fixed_factor(NULL, "sys_clk", "pll1", 0, 1, 4);
pp[2] = clk_register_fixed_factor(NULL, "usb_clk", "cd2", 0, 1, 2);
pp[3] = clk_register_fixed_factor(NULL, "sdio_clk", "cd6", 0, 1, 2);
if (IS_ERR(pp[0]) || IS_ERR(pp[1]) || IS_ERR(pp[2]) || IS_ERR(pp[3]))
panic("%s: clk registration failed\n", np->name);
if (of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data))
panic("%s: clk provider registration failed\n", np->name);
}
CLK_OF_DECLARE(tango4_clkgen, "sigma,tango4-clkgen", tango4_clkgen_setup);