diff options
author | Rob Herring <rob.herring@calxeda.com> | 2012-03-13 18:19:19 -0500 |
---|---|---|
committer | Mike Turquette <mturquette@linaro.org> | 2012-07-11 17:58:47 -0700 |
commit | 8d4d9f52081cd45bde42b9452eba95f38feb7dae (patch) | |
tree | 81b614f5f842150c910737a9e1f5414de3b49b4b /drivers/clk/clk-highbank.c | |
parent | 260b6aa03edd87a3a85c137e7b95305d9eb40485 (diff) | |
download | linux-8d4d9f52081cd45bde42b9452eba95f38feb7dae.tar.bz2 |
clk: add highbank clock support
This adds real clock support to Calxeda Highbank SOC using the common
clock infrastructure.
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
[mturquette@linaro.org: fixed up invalid writes to const struct member]
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Diffstat (limited to 'drivers/clk/clk-highbank.c')
-rw-r--r-- | drivers/clk/clk-highbank.c | 346 |
1 files changed, 346 insertions, 0 deletions
diff --git a/drivers/clk/clk-highbank.c b/drivers/clk/clk-highbank.c new file mode 100644 index 000000000000..52fecadf004a --- /dev/null +++ b/drivers/clk/clk-highbank.c @@ -0,0 +1,346 @@ +/* + * Copyright 2011-2012 Calxeda, Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/err.h> +#include <linux/clk-provider.h> +#include <linux/io.h> +#include <linux/of.h> + +extern void __iomem *sregs_base; + +#define HB_PLL_LOCK_500 0x20000000 +#define HB_PLL_LOCK 0x10000000 +#define HB_PLL_DIVF_SHIFT 20 +#define HB_PLL_DIVF_MASK 0x0ff00000 +#define HB_PLL_DIVQ_SHIFT 16 +#define HB_PLL_DIVQ_MASK 0x00070000 +#define HB_PLL_DIVR_SHIFT 8 +#define HB_PLL_DIVR_MASK 0x00001f00 +#define HB_PLL_RANGE_SHIFT 4 +#define HB_PLL_RANGE_MASK 0x00000070 +#define HB_PLL_BYPASS 0x00000008 +#define HB_PLL_RESET 0x00000004 +#define HB_PLL_EXT_BYPASS 0x00000002 +#define HB_PLL_EXT_ENA 0x00000001 + +#define HB_PLL_VCO_MIN_FREQ 2133000000 +#define HB_PLL_MAX_FREQ HB_PLL_VCO_MIN_FREQ +#define HB_PLL_MIN_FREQ (HB_PLL_VCO_MIN_FREQ / 64) + +#define HB_A9_BCLK_DIV_MASK 0x00000006 +#define HB_A9_BCLK_DIV_SHIFT 1 +#define HB_A9_PCLK_DIV 0x00000001 + +struct hb_clk { + struct clk_hw hw; + void __iomem *reg; + char *parent_name; +}; +#define to_hb_clk(p) container_of(p, struct hb_clk, hw) + +static int clk_pll_prepare(struct clk_hw *hwclk) + { + struct hb_clk *hbclk = to_hb_clk(hwclk); + u32 reg; + + reg = readl(hbclk->reg); + reg &= ~HB_PLL_RESET; + writel(reg, hbclk->reg); + + while ((readl(hbclk->reg) & HB_PLL_LOCK) == 0) + ; + while ((readl(hbclk->reg) & HB_PLL_LOCK_500) == 0) + ; + + return 0; +} + +static void clk_pll_unprepare(struct clk_hw *hwclk) +{ + struct hb_clk *hbclk = to_hb_clk(hwclk); + u32 reg; + + reg = readl(hbclk->reg); + reg |= HB_PLL_RESET; + writel(reg, hbclk->reg); +} + +static int clk_pll_enable(struct clk_hw *hwclk) +{ + struct hb_clk *hbclk = to_hb_clk(hwclk); + u32 reg; + + reg = readl(hbclk->reg); + reg |= HB_PLL_EXT_ENA; + writel(reg, hbclk->reg); + + return 0; +} + +static void clk_pll_disable(struct clk_hw *hwclk) +{ + struct hb_clk *hbclk = to_hb_clk(hwclk); + u32 reg; + + reg = readl(hbclk->reg); + reg &= ~HB_PLL_EXT_ENA; + writel(reg, hbclk->reg); +} + +static unsigned long clk_pll_recalc_rate(struct clk_hw *hwclk, + unsigned long parent_rate) +{ + struct hb_clk *hbclk = to_hb_clk(hwclk); + unsigned long divf, divq, vco_freq, reg; + + reg = readl(hbclk->reg); + if (reg & HB_PLL_EXT_BYPASS) + return parent_rate; + + divf = (reg & HB_PLL_DIVF_MASK) >> HB_PLL_DIVF_SHIFT; + divq = (reg & HB_PLL_DIVQ_MASK) >> HB_PLL_DIVQ_SHIFT; + vco_freq = parent_rate * (divf + 1); + + return vco_freq / (1 << divq); +} + +static void clk_pll_calc(unsigned long rate, unsigned long ref_freq, + u32 *pdivq, u32 *pdivf) +{ + u32 divq, divf; + unsigned long vco_freq; + + if (rate < HB_PLL_MIN_FREQ) + rate = HB_PLL_MIN_FREQ; + if (rate > HB_PLL_MAX_FREQ) + rate = HB_PLL_MAX_FREQ; + + for (divq = 1; divq <= 6; divq++) { + if ((rate * (1 << divq)) >= HB_PLL_VCO_MIN_FREQ) + break; + } + + vco_freq = rate * (1 << divq); + divf = (vco_freq + (ref_freq / 2)) / ref_freq; + divf--; + + *pdivq = divq; + *pdivf = divf; +} + +static long clk_pll_round_rate(struct clk_hw *hwclk, unsigned long rate, + unsigned long *parent_rate) +{ + u32 divq, divf; + unsigned long ref_freq = *parent_rate; + + clk_pll_calc(rate, ref_freq, &divq, &divf); + + return (ref_freq * (divf + 1)) / (1 << divq); +} + +static int clk_pll_set_rate(struct clk_hw *hwclk, unsigned long rate, + unsigned long parent_rate) +{ + struct hb_clk *hbclk = to_hb_clk(hwclk); + u32 divq, divf; + u32 reg; + + clk_pll_calc(rate, parent_rate, &divq, &divf); + + reg = readl(hbclk->reg); + if (divf != ((reg & HB_PLL_DIVF_MASK) >> HB_PLL_DIVF_SHIFT)) { + /* Need to re-lock PLL, so put it into bypass mode */ + reg |= HB_PLL_EXT_BYPASS; + writel(reg | HB_PLL_EXT_BYPASS, hbclk->reg); + + writel(reg | HB_PLL_RESET, hbclk->reg); + reg &= ~(HB_PLL_DIVF_MASK | HB_PLL_DIVQ_MASK); + reg |= (divf << HB_PLL_DIVF_SHIFT) | (divq << HB_PLL_DIVQ_SHIFT); + writel(reg | HB_PLL_RESET, hbclk->reg); + writel(reg, hbclk->reg); + + while ((readl(hbclk->reg) & HB_PLL_LOCK) == 0) + ; + while ((readl(hbclk->reg) & HB_PLL_LOCK_500) == 0) + ; + reg |= HB_PLL_EXT_ENA; + reg &= ~HB_PLL_EXT_BYPASS; + } else { + reg &= ~HB_PLL_DIVQ_MASK; + reg |= divq << HB_PLL_DIVQ_SHIFT; + } + writel(reg, hbclk->reg); + + return 0; +} + +static const struct clk_ops clk_pll_ops = { + .prepare = clk_pll_prepare, + .unprepare = clk_pll_unprepare, + .enable = clk_pll_enable, + .disable = clk_pll_disable, + .recalc_rate = clk_pll_recalc_rate, + .round_rate = clk_pll_round_rate, + .set_rate = clk_pll_set_rate, +}; + +static unsigned long clk_cpu_periphclk_recalc_rate(struct clk_hw *hwclk, + unsigned long parent_rate) +{ + struct hb_clk *hbclk = to_hb_clk(hwclk); + u32 div = (readl(hbclk->reg) & HB_A9_PCLK_DIV) ? 8 : 4; + return parent_rate / div; +} + +static const struct clk_ops a9periphclk_ops = { + .recalc_rate = clk_cpu_periphclk_recalc_rate, +}; + +static unsigned long clk_cpu_a9bclk_recalc_rate(struct clk_hw *hwclk, + unsigned long parent_rate) +{ + struct hb_clk *hbclk = to_hb_clk(hwclk); + u32 div = (readl(hbclk->reg) & HB_A9_BCLK_DIV_MASK) >> HB_A9_BCLK_DIV_SHIFT; + + return parent_rate / (div + 2); +} + +static const struct clk_ops a9bclk_ops = { + .recalc_rate = clk_cpu_a9bclk_recalc_rate, +}; + +static unsigned long clk_periclk_recalc_rate(struct clk_hw *hwclk, + unsigned long parent_rate) +{ + struct hb_clk *hbclk = to_hb_clk(hwclk); + u32 div; + + div = readl(hbclk->reg) & 0x1f; + div++; + div *= 2; + + return parent_rate / div; +} + +static long clk_periclk_round_rate(struct clk_hw *hwclk, unsigned long rate, + unsigned long *parent_rate) +{ + u32 div; + + div = *parent_rate / rate; + div++; + div &= ~0x1; + + return *parent_rate / div; +} + +static int clk_periclk_set_rate(struct clk_hw *hwclk, unsigned long rate, + unsigned long parent_rate) +{ + struct hb_clk *hbclk = to_hb_clk(hwclk); + u32 div; + + div = parent_rate / rate; + if (div & 0x1) + return -EINVAL; + + writel(div >> 1, hbclk->reg); + return 0; +} + +static const struct clk_ops periclk_ops = { + .recalc_rate = clk_periclk_recalc_rate, + .round_rate = clk_periclk_round_rate, + .set_rate = clk_periclk_set_rate, +}; + +static __init struct clk *hb_clk_init(struct device_node *node, const struct clk_ops *ops) +{ + u32 reg; + struct clk *clk; + struct hb_clk *hb_clk; + const char *clk_name = node->name; + const char *parent_name; + struct clk_init_data init; + int rc; + + rc = of_property_read_u32(node, "reg", ®); + if (WARN_ON(rc)) + return NULL; + + hb_clk = kzalloc(sizeof(*hb_clk), GFP_KERNEL); + if (WARN_ON(!hb_clk)) + return NULL; + + hb_clk->reg = sregs_base + reg; + + of_property_read_string(node, "clock-output-names", &clk_name); + + init.name = clk_name; + init.ops = ops; + init.flags = 0; + parent_name = of_clk_get_parent_name(node, 0); + init.parent_names = &parent_name; + init.num_parents = 1; + + hb_clk->hw.init = &init; + + clk = clk_register(NULL, &hb_clk->hw); + if (WARN_ON(IS_ERR(clk))) { + kfree(hb_clk); + return NULL; + } + rc = of_clk_add_provider(node, of_clk_src_simple_get, clk); + return clk; +} + +static void __init hb_pll_init(struct device_node *node) +{ + hb_clk_init(node, &clk_pll_ops); +} + +static void __init hb_a9periph_init(struct device_node *node) +{ + hb_clk_init(node, &a9periphclk_ops); +} + +static void __init hb_a9bus_init(struct device_node *node) +{ + struct clk *clk = hb_clk_init(node, &a9bclk_ops); + clk_prepare_enable(clk); +} + +static void __init hb_emmc_init(struct device_node *node) +{ + hb_clk_init(node, &periclk_ops); +} + +static const __initconst struct of_device_id clk_match[] = { + { .compatible = "fixed-clock", .data = of_fixed_clk_setup, }, + { .compatible = "calxeda,hb-pll-clock", .data = hb_pll_init, }, + { .compatible = "calxeda,hb-a9periph-clock", .data = hb_a9periph_init, }, + { .compatible = "calxeda,hb-a9bus-clock", .data = hb_a9bus_init, }, + { .compatible = "calxeda,hb-emmc-clock", .data = hb_emmc_init, }, + {} +}; + +void __init highbank_clocks_init(void) +{ + of_clk_init(clk_match); +} |