diff options
Diffstat (limited to 'drivers/clk/versatile/clk-icst.c')
| -rw-r--r-- | drivers/clk/versatile/clk-icst.c | 197 |
1 files changed, 164 insertions, 33 deletions
diff --git a/drivers/clk/versatile/clk-icst.c b/drivers/clk/versatile/clk-icst.c index 08c5ee976..3bca438ec 100644 --- a/drivers/clk/versatile/clk-icst.c +++ b/drivers/clk/versatile/clk-icst.c @@ -3,7 +3,7 @@ * We wrap the custom interface from <asm/hardware/icst.h> into the generic * clock framework. * - * Copyright (C) 2012 Linus Walleij + * Copyright (C) 2012-2015 Linus Walleij * * 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 @@ -19,9 +19,14 @@ #include <linux/err.h> #include <linux/clk-provider.h> #include <linux/io.h> +#include <linux/regmap.h> +#include <linux/mfd/syscon.h> #include "clk-icst.h" +/* Magic unlocking token used on all Versatile boards */ +#define VERSATILE_LOCK_VAL 0xA05F + /** * struct clk_icst - ICST VCO clock wrapper * @hw: corresponding clock hardware entry @@ -32,8 +37,9 @@ */ struct clk_icst { struct clk_hw hw; - void __iomem *vcoreg; - void __iomem *lockreg; + struct regmap *map; + u32 vcoreg_off; + u32 lockreg_off; struct icst_params *params; unsigned long rate; }; @@ -41,53 +47,70 @@ struct clk_icst { #define to_icst(_hw) container_of(_hw, struct clk_icst, hw) /** - * vco_get() - get ICST VCO settings from a certain register - * @vcoreg: register containing the VCO settings + * vco_get() - get ICST VCO settings from a certain ICST + * @icst: the ICST clock to get + * @vco: the VCO struct to return the value in */ -static struct icst_vco vco_get(void __iomem *vcoreg) +static int vco_get(struct clk_icst *icst, struct icst_vco *vco) { u32 val; - struct icst_vco vco; + int ret; - val = readl(vcoreg); - vco.v = val & 0x1ff; - vco.r = (val >> 9) & 0x7f; - vco.s = (val >> 16) & 03; - return vco; + ret = regmap_read(icst->map, icst->vcoreg_off, &val); + if (ret) + return ret; + vco->v = val & 0x1ff; + vco->r = (val >> 9) & 0x7f; + vco->s = (val >> 16) & 03; + return 0; } /** * vco_set() - commit changes to an ICST VCO - * @locreg: register to poke to unlock the VCO for writing - * @vcoreg: register containing the VCO settings - * @vco: ICST VCO parameters to commit + * @icst: the ICST clock to set + * @vco: the VCO struct to set the changes from */ -static void vco_set(void __iomem *lockreg, - void __iomem *vcoreg, - struct icst_vco vco) +static int vco_set(struct clk_icst *icst, struct icst_vco vco) { u32 val; + int ret; - val = readl(vcoreg) & ~0x7ffff; + ret = regmap_read(icst->map, icst->vcoreg_off, &val); + if (ret) + return ret; + + /* Mask the 18 bits used by the VCO */ + val &= ~0x7ffff; val |= vco.v | (vco.r << 9) | (vco.s << 16); /* This magic unlocks the VCO so it can be controlled */ - writel(0xa05f, lockreg); - writel(val, vcoreg); + ret = regmap_write(icst->map, icst->lockreg_off, VERSATILE_LOCK_VAL); + if (ret) + return ret; + ret = regmap_write(icst->map, icst->vcoreg_off, val); + if (ret) + return ret; /* This locks the VCO again */ - writel(0, lockreg); + ret = regmap_write(icst->map, icst->lockreg_off, 0); + if (ret) + return ret; + return 0; } - static unsigned long icst_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { struct clk_icst *icst = to_icst(hw); struct icst_vco vco; + int ret; if (parent_rate) icst->params->ref = parent_rate; - vco = vco_get(icst->vcoreg); + ret = vco_get(icst, &vco); + if (ret) { + pr_err("ICST: could not get VCO setting\n"); + return 0; + } icst->rate = icst_hz(icst->params, vco); return icst->rate; } @@ -112,8 +135,7 @@ static int icst_set_rate(struct clk_hw *hw, unsigned long rate, icst->params->ref = parent_rate; vco = icst_hz_to_vco(icst->params, rate); icst->rate = icst_hz(icst->params, vco); - vco_set(icst->lockreg, icst->vcoreg, vco); - return 0; + return vco_set(icst, vco); } static const struct clk_ops icst_ops = { @@ -122,11 +144,11 @@ static const struct clk_ops icst_ops = { .set_rate = icst_set_rate, }; -struct clk *icst_clk_register(struct device *dev, - const struct clk_icst_desc *desc, - const char *name, - const char *parent_name, - void __iomem *base) +static struct clk *icst_clk_setup(struct device *dev, + const struct clk_icst_desc *desc, + const char *name, + const char *parent_name, + struct regmap *map) { struct clk *clk; struct clk_icst *icst; @@ -151,10 +173,11 @@ struct clk *icst_clk_register(struct device *dev, init.flags = CLK_IS_ROOT; init.parent_names = (parent_name ? &parent_name : NULL); init.num_parents = (parent_name ? 1 : 0); + icst->map = map; icst->hw.init = &init; icst->params = pclone; - icst->vcoreg = base + desc->vco_offset; - icst->lockreg = base + desc->lock_offset; + icst->vcoreg_off = desc->vco_offset; + icst->lockreg_off = desc->lock_offset; clk = clk_register(dev, &icst->hw); if (IS_ERR(clk)) { @@ -164,4 +187,112 @@ struct clk *icst_clk_register(struct device *dev, return clk; } + +struct clk *icst_clk_register(struct device *dev, + const struct clk_icst_desc *desc, + const char *name, + const char *parent_name, + void __iomem *base) +{ + struct regmap_config icst_regmap_conf = { + .reg_bits = 32, + .val_bits = 32, + .reg_stride = 4, + }; + struct regmap *map; + + map = regmap_init_mmio(dev, base, &icst_regmap_conf); + if (IS_ERR(map)) { + pr_err("could not initialize ICST regmap\n"); + return ERR_CAST(map); + } + return icst_clk_setup(dev, desc, name, parent_name, map); +} EXPORT_SYMBOL_GPL(icst_clk_register); + +#ifdef CONFIG_OF +/* + * In a device tree, an memory-mapped ICST clock appear as a child + * of a syscon node. Assume this and probe it only as a child of a + * syscon. + */ + +static const struct icst_params icst525_params = { + .vco_max = ICST525_VCO_MAX_5V, + .vco_min = ICST525_VCO_MIN, + .vd_min = 8, + .vd_max = 263, + .rd_min = 3, + .rd_max = 65, + .s2div = icst525_s2div, + .idx2s = icst525_idx2s, +}; + +static const struct icst_params icst307_params = { + .vco_max = ICST307_VCO_MAX, + .vco_min = ICST307_VCO_MIN, + .vd_min = 4 + 8, + .vd_max = 511 + 8, + .rd_min = 1 + 2, + .rd_max = 127 + 2, + .s2div = icst307_s2div, + .idx2s = icst307_idx2s, +}; + +static void __init of_syscon_icst_setup(struct device_node *np) +{ + struct device_node *parent; + struct regmap *map; + struct clk_icst_desc icst_desc; + const char *name = np->name; + const char *parent_name; + struct clk *regclk; + + /* We do not release this reference, we are using it perpetually */ + parent = of_get_parent(np); + if (!parent) { + pr_err("no parent node for syscon ICST clock\n"); + return; + } + map = syscon_node_to_regmap(parent); + if (IS_ERR(map)) { + pr_err("no regmap for syscon ICST clock parent\n"); + return; + } + + if (of_property_read_u32(np, "vco-offset", &icst_desc.vco_offset)) { + pr_err("no VCO register offset for ICST clock\n"); + return; + } + if (of_property_read_u32(np, "lock-offset", &icst_desc.lock_offset)) { + pr_err("no lock register offset for ICST clock\n"); + return; + } + + if (of_device_is_compatible(np, "arm,syscon-icst525")) + icst_desc.params = &icst525_params; + else if (of_device_is_compatible(np, "arm,syscon-icst307")) + icst_desc.params = &icst307_params; + else { + pr_err("unknown ICST clock %s\n", name); + return; + } + + /* Parent clock name is not the same as node parent */ + parent_name = of_clk_get_parent_name(np, 0); + + regclk = icst_clk_setup(NULL, &icst_desc, name, parent_name, map); + if (IS_ERR(regclk)) { + pr_err("error setting up syscon ICST clock %s\n", name); + return; + } + of_clk_add_provider(np, of_clk_src_simple_get, regclk); + pr_debug("registered syscon ICST clock %s\n", name); +} + +CLK_OF_DECLARE(arm_syscon_icst525_clk, + "arm,syscon-icst525", of_syscon_icst_setup); +CLK_OF_DECLARE(arm_syscon_icst307_clk, + "arm,syscon-icst307", of_syscon_icst_setup); + +#endif |