diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-15 07:05:03 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-15 07:05:03 +0200 |
commit | c0fa2373f8cfed90437d8d7b17e0b1a84009a10a (patch) | |
tree | 43fb2edd0c11874d0b2e56714e53894d10321e19 /drivers/clk/sunxi/clk-mod0.c | |
parent | fcc3a5d277571bc6048e7b4ef8cd391b935de629 (diff) | |
parent | 98d147f50eb0ce4328e013f5f2c076896003c761 (diff) |
Merge tag 'clk-for-linus-3.18' of git://git.linaro.org/people/mike.turquette/linux
Pull clock tree updates from Mike Turquette:
"The clk tree changes for 3.18 are dominated by clock drivers. Mostly
fixes and enhancements to existing drivers as well as new drivers.
This tag contains a bit more arch code than I usually take due to some
OMAP2+ changes. Additionally it contains the restart notifier
handlers which are merged as a dependency into several trees.
The PXA changes are the only messy part. Due to having a stable tree
I had to revert one patch and follow up with one more fix near the tip
of this tag. Some dead code is introduced but it will soon become
live code after 3.18-rc1 is released as the rest of the PXA family is
converted over to the common clock framework.
Another trend in this tag is that multiple vendors have started to
push the complexity of changing their CPU frequency into the clock
driver, whereas this used to be done in CPUfreq drivers.
Changes to the clk core include a generic gpio-clock type and a
clk_set_phase() function added to the top-level clk.h api. Due to
some confusion on the fbdev mailing list the kernel boot parameters
documentation was updated to further explain the clk_ignore_unused
parameter, which is often required by users of the simplefb driver.
Finally some fixes to the locking around the clock debugfs stuff was
done to prevent deadlocks when interacting with other subsystems."
* tag 'clk-for-linus-3.18' of git://git.linaro.org/people/mike.turquette/linux: (99 commits)
clk: pxa clocks build system fix
Revert "arm: pxa: Transition pxa27x to clk framework"
clk: samsung: register restart handlers for s3c2412 and s3c2443
clk: rockchip: add restart handler
clk: rockchip: rk3288: i2s_frac adds flag to set parent's rate
doc/kernel-parameters.txt: clarify clk_ignore_unused
arm: pxa: Transition pxa27x to clk framework
dts: add devicetree bindings for pxa27x clocks
clk: add pxa27x clock drivers
arm: pxa: add clock pll selection bits
clk: dts: document pxa clock binding
clk: add pxa clocks infrastructure
clk: gpio-gate: Ensure gpiod_ APIs are prototyped
clk: ti: dra7-atl-clock: Mark the device as pm_runtime_irq_safe
clk: ti: LLVMLinux: Move __init outside of type definition
clk: ti: consider the fact that of_clk_get() might return an error
clk: ti: dra7-atl-clock: fix a memory leak
clk: ti: change clock init to use generic of_clk_init
clk: hix5hd2: add I2C clocks
clk: hix5hd2: add watchdog0 clocks
...
Diffstat (limited to 'drivers/clk/sunxi/clk-mod0.c')
-rw-r--r-- | drivers/clk/sunxi/clk-mod0.c | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/drivers/clk/sunxi/clk-mod0.c b/drivers/clk/sunxi/clk-mod0.c new file mode 100644 index 000000000000..4a563850ee6e --- /dev/null +++ b/drivers/clk/sunxi/clk-mod0.c @@ -0,0 +1,283 @@ +/* + * Copyright 2013 Emilio López + * + * Emilio López <emilio@elopez.com.ar> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that 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. + */ + +#include <linux/clk-provider.h> +#include <linux/clkdev.h> +#include <linux/of_address.h> + +#include "clk-factors.h" + +/** + * sun4i_get_mod0_factors() - calculates m, n factors for MOD0-style clocks + * MOD0 rate is calculated as follows + * rate = (parent_rate >> p) / (m + 1); + */ + +static void sun4i_a10_get_mod0_factors(u32 *freq, u32 parent_rate, + u8 *n, u8 *k, u8 *m, u8 *p) +{ + u8 div, calcm, calcp; + + /* These clocks can only divide, so we will never be able to achieve + * frequencies higher than the parent frequency */ + if (*freq > parent_rate) + *freq = parent_rate; + + div = DIV_ROUND_UP(parent_rate, *freq); + + if (div < 16) + calcp = 0; + else if (div / 2 < 16) + calcp = 1; + else if (div / 4 < 16) + calcp = 2; + else + calcp = 3; + + calcm = DIV_ROUND_UP(div, 1 << calcp); + + *freq = (parent_rate >> calcp) / calcm; + + /* we were called to round the frequency, we can now return */ + if (n == NULL) + return; + + *m = calcm - 1; + *p = calcp; +} + +/* user manual says "n" but it's really "p" */ +static struct clk_factors_config sun4i_a10_mod0_config = { + .mshift = 0, + .mwidth = 4, + .pshift = 16, + .pwidth = 2, +}; + +static const struct factors_data sun4i_a10_mod0_data __initconst = { + .enable = 31, + .mux = 24, + .table = &sun4i_a10_mod0_config, + .getter = sun4i_a10_get_mod0_factors, +}; + +static DEFINE_SPINLOCK(sun4i_a10_mod0_lock); + +static void __init sun4i_a10_mod0_setup(struct device_node *node) +{ + sunxi_factors_register(node, &sun4i_a10_mod0_data, &sun4i_a10_mod0_lock); +} +CLK_OF_DECLARE(sun4i_a10_mod0, "allwinner,sun4i-a10-mod0-clk", sun4i_a10_mod0_setup); + +static DEFINE_SPINLOCK(sun5i_a13_mbus_lock); + +static void __init sun5i_a13_mbus_setup(struct device_node *node) +{ + struct clk *mbus = sunxi_factors_register(node, &sun4i_a10_mod0_data, &sun5i_a13_mbus_lock); + + /* The MBUS clocks needs to be always enabled */ + __clk_get(mbus); + clk_prepare_enable(mbus); +} +CLK_OF_DECLARE(sun5i_a13_mbus, "allwinner,sun5i-a13-mbus-clk", sun5i_a13_mbus_setup); + +struct mmc_phase_data { + u8 offset; +}; + +struct mmc_phase { + struct clk_hw hw; + void __iomem *reg; + struct mmc_phase_data *data; + spinlock_t *lock; +}; + +#define to_mmc_phase(_hw) container_of(_hw, struct mmc_phase, hw) + +static int mmc_get_phase(struct clk_hw *hw) +{ + struct clk *mmc, *mmc_parent, *clk = hw->clk; + struct mmc_phase *phase = to_mmc_phase(hw); + unsigned int mmc_rate, mmc_parent_rate; + u16 step, mmc_div; + u32 value; + u8 delay; + + value = readl(phase->reg); + delay = (value >> phase->data->offset) & 0x3; + + if (!delay) + return 180; + + /* Get the main MMC clock */ + mmc = clk_get_parent(clk); + if (!mmc) + return -EINVAL; + + /* And its rate */ + mmc_rate = clk_get_rate(mmc); + if (!mmc_rate) + return -EINVAL; + + /* Now, get the MMC parent (most likely some PLL) */ + mmc_parent = clk_get_parent(mmc); + if (!mmc_parent) + return -EINVAL; + + /* And its rate */ + mmc_parent_rate = clk_get_rate(mmc_parent); + if (!mmc_parent_rate) + return -EINVAL; + + /* Get MMC clock divider */ + mmc_div = mmc_parent_rate / mmc_rate; + + step = DIV_ROUND_CLOSEST(360, mmc_div); + return delay * step; +} + +static int mmc_set_phase(struct clk_hw *hw, int degrees) +{ + struct clk *mmc, *mmc_parent, *clk = hw->clk; + struct mmc_phase *phase = to_mmc_phase(hw); + unsigned int mmc_rate, mmc_parent_rate; + unsigned long flags; + u32 value; + u8 delay; + + /* Get the main MMC clock */ + mmc = clk_get_parent(clk); + if (!mmc) + return -EINVAL; + + /* And its rate */ + mmc_rate = clk_get_rate(mmc); + if (!mmc_rate) + return -EINVAL; + + /* Now, get the MMC parent (most likely some PLL) */ + mmc_parent = clk_get_parent(mmc); + if (!mmc_parent) + return -EINVAL; + + /* And its rate */ + mmc_parent_rate = clk_get_rate(mmc_parent); + if (!mmc_parent_rate) + return -EINVAL; + + if (degrees != 180) { + u16 step, mmc_div; + + /* Get MMC clock divider */ + mmc_div = mmc_parent_rate / mmc_rate; + + /* + * We can only outphase the clocks by multiple of the + * PLL's period. + * + * Since the MMC clock in only a divider, and the + * formula to get the outphasing in degrees is deg = + * 360 * delta / period + * + * If we simplify this formula, we can see that the + * only thing that we're concerned about is the number + * of period we want to outphase our clock from, and + * the divider set by the MMC clock. + */ + step = DIV_ROUND_CLOSEST(360, mmc_div); + delay = DIV_ROUND_CLOSEST(degrees, step); + } else { + delay = 0; + } + + spin_lock_irqsave(phase->lock, flags); + value = readl(phase->reg); + value &= ~GENMASK(phase->data->offset + 3, phase->data->offset); + value |= delay << phase->data->offset; + writel(value, phase->reg); + spin_unlock_irqrestore(phase->lock, flags); + + return 0; +} + +static const struct clk_ops mmc_clk_ops = { + .get_phase = mmc_get_phase, + .set_phase = mmc_set_phase, +}; + +static void __init sun4i_a10_mmc_phase_setup(struct device_node *node, + struct mmc_phase_data *data) +{ + const char *parent_names[1] = { of_clk_get_parent_name(node, 0) }; + struct clk_init_data init = { + .num_parents = 1, + .parent_names = parent_names, + .ops = &mmc_clk_ops, + }; + + struct mmc_phase *phase; + struct clk *clk; + + phase = kmalloc(sizeof(*phase), GFP_KERNEL); + if (!phase) + return; + + phase->hw.init = &init; + + phase->reg = of_iomap(node, 0); + if (!phase->reg) + goto err_free; + + phase->data = data; + phase->lock = &sun4i_a10_mod0_lock; + + if (of_property_read_string(node, "clock-output-names", &init.name)) + init.name = node->name; + + clk = clk_register(NULL, &phase->hw); + if (IS_ERR(clk)) + goto err_unmap; + + of_clk_add_provider(node, of_clk_src_simple_get, clk); + + return; + +err_unmap: + iounmap(phase->reg); +err_free: + kfree(phase); +} + + +static struct mmc_phase_data mmc_output_clk = { + .offset = 8, +}; + +static struct mmc_phase_data mmc_sample_clk = { + .offset = 20, +}; + +static void __init sun4i_a10_mmc_output_setup(struct device_node *node) +{ + sun4i_a10_mmc_phase_setup(node, &mmc_output_clk); +} +CLK_OF_DECLARE(sun4i_a10_mmc_output, "allwinner,sun4i-a10-mmc-output-clk", sun4i_a10_mmc_output_setup); + +static void __init sun4i_a10_mmc_sample_setup(struct device_node *node) +{ + sun4i_a10_mmc_phase_setup(node, &mmc_sample_clk); +} +CLK_OF_DECLARE(sun4i_a10_mmc_sample, "allwinner,sun4i-a10-mmc-sample-clk", sun4i_a10_mmc_sample_setup); |