diff options
Diffstat (limited to 'drivers/clk/renesas/clk-rz.c')
-rw-r--r-- | drivers/clk/renesas/clk-rz.c | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/drivers/clk/renesas/clk-rz.c b/drivers/clk/renesas/clk-rz.c new file mode 100644 index 0000000000..e770f09a27 --- /dev/null +++ b/drivers/clk/renesas/clk-rz.c @@ -0,0 +1,121 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * RZ/A1 Core CPG Clocks + * + * Copyright (C) 2013 Ideas On Board SPRL + * Copyright (C) 2014 Wolfram Sang, Sang Engineering <wsa@sang-engineering.com> + */ + +#include <linux/clk-provider.h> +#include <linux/clk/renesas.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/slab.h> + +#define CPG_FRQCR 0x10 +#define CPG_FRQCR2 0x14 + +#define PPR0 0xFCFE3200 +#define PIBC0 0xFCFE7000 + +#define MD_CLK(x) ((x >> 2) & 1) /* P0_2 */ + +/* ----------------------------------------------------------------------------- + * Initialization + */ + +static u16 __init rz_cpg_read_mode_pins(void) +{ + void __iomem *ppr0, *pibc0; + u16 modes; + + ppr0 = ioremap(PPR0, 2); + pibc0 = ioremap(PIBC0, 2); + BUG_ON(!ppr0 || !pibc0); + iowrite16(4, pibc0); /* enable input buffer */ + modes = ioread16(ppr0); + iounmap(ppr0); + iounmap(pibc0); + + return modes; +} + +static struct clk * __init +rz_cpg_register_clock(struct device_node *np, void __iomem *base, + const char *name) +{ + u32 val; + unsigned mult; + static const unsigned frqcr_tab[4] = { 3, 2, 0, 1 }; + + if (strcmp(name, "pll") == 0) { + unsigned int cpg_mode = MD_CLK(rz_cpg_read_mode_pins()); + const char *parent_name = of_clk_get_parent_name(np, cpg_mode); + + mult = cpg_mode ? (32 / 4) : 30; + + return clk_register_fixed_factor(NULL, name, parent_name, 0, mult, 1); + } + + /* If mapping regs failed, skip non-pll clocks. System will boot anyhow */ + if (!base) + return ERR_PTR(-ENXIO); + + /* FIXME:"i" and "g" are variable clocks with non-integer dividers (e.g. 2/3) + * and the constraint that always g <= i. To get the rz platform started, + * let them run at fixed current speed and implement the details later. + */ + if (strcmp(name, "i") == 0) + val = (readl(base + CPG_FRQCR) >> 8) & 3; + else if (strcmp(name, "g") == 0) + val = readl(base + CPG_FRQCR2) & 3; + else + return ERR_PTR(-EINVAL); + + mult = frqcr_tab[val]; + return clk_register_fixed_factor(NULL, name, "pll", 0, mult, 3); +} + +static void __init rz_cpg_clocks_init(struct device_node *np) +{ + struct clk_onecell_data *data; + struct clk **clks; + void __iomem *base; + unsigned i; + int num_clks; + + num_clks = of_property_count_strings(np, "clock-output-names"); + if (WARN(num_clks <= 0, "can't count CPG clocks\n")) + return; + + data = kzalloc(sizeof(*data), GFP_KERNEL); + clks = kcalloc(num_clks, sizeof(*clks), GFP_KERNEL); + BUG_ON(!data || !clks); + + data->clks = clks; + data->clk_num = num_clks; + + base = of_iomap(np, 0); + + for (i = 0; i < num_clks; ++i) { + const char *name; + struct clk *clk; + + of_property_read_string_index(np, "clock-output-names", i, &name); + + clk = rz_cpg_register_clock(np, base, name); + if (IS_ERR(clk)) + pr_err("%s: failed to register %pOFn %s clock (%ld)\n", + __func__, np, name, PTR_ERR(clk)); + else + data->clks[i] = clk; + } + + of_clk_add_provider(np, of_clk_src_onecell_get, data); + + cpg_mstp_add_clk_domain(np); +} +CLK_OF_DECLARE(rz_cpg_clks, "renesas,rz-cpg-clocks", rz_cpg_clocks_init); |