diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-12-20 16:42:36 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-12-20 16:42:36 -0800 |
commit | bfc7249cc293deac8f2678b7ec3d2407b68c0a33 (patch) | |
tree | 6a73d533cc72fbc583ca1af46defe7d3c26d2751 /drivers/clk/rockchip/clk-mmc-phase.c | |
parent | a4e1328a9d20ccf4a9e5a19fce172e6deb2a33e2 (diff) | |
parent | f1e9203e2366164b832d8a6ce10134de8c575178 (diff) | |
download | blackbird-obmc-linux-bfc7249cc293deac8f2678b7ec3d2407b68c0a33.tar.gz blackbird-obmc-linux-bfc7249cc293deac8f2678b7ec3d2407b68c0a33.zip |
Merge tag 'clk-for-linus-3.19' of git://git.linaro.org/people/mike.turquette/linux
Pull clk framework updates from Mike Turquette:
"This is much later than usual due to several last minute bugs that had
to be addressed. As usual the majority of changes are new drivers and
modifications to existing drivers. The core recieved many fixes along
with the groundwork for several large changes coming in the future
which will better parition clock providers from clock consumers"
* tag 'clk-for-linus-3.19' of git://git.linaro.org/people/mike.turquette/linux: (86 commits)
clk: samsung: Fix Exynos 5420 pinctrl setup and clock disable failure due to domain being gated
ARM: OMAP3: clock: fix boot breakage in legacy mode
ARM: OMAP2+: clock: fix DPLL code to use new determine rate APIs
clk: Really fix deadlock with mmap_sem
clk: mmp: fix sparse non static symbol warning
clk: Change clk_ops->determine_rate to return a clk_hw as the best parent
clk: change clk_debugfs_add_file to take a struct clk_hw
clk: Don't expose __clk_get_accuracy
clk: Don't try to use a struct clk* after it could have been freed
clk: Remove unused function __clk_get_prepare_count
clk: samsung: Fix double add of syscore ops after driver rebind
clk: samsung: exynos4: set parent of sclk_hdmiphy to hdmi
clk: samsung: exynos4415: Fix build with PM_SLEEP disabled
clk: samsung: remove unnecessary inclusion of header files from clk.h
clk: samsung: remove unnecessary CONFIG_OF from clk.c
clk: samsung: Spelling s/bwtween/between/
clk: rockchip: Add support for the mmc clock phases using the framework
clk: rockchip: add bindings for the mmc clocks
clk: rockchip: rk3288 export i2s0_clkout for use in DT
clk: rockchip: use clock ID for DMC (memory controller) on rk3288
...
Diffstat (limited to 'drivers/clk/rockchip/clk-mmc-phase.c')
-rw-r--r-- | drivers/clk/rockchip/clk-mmc-phase.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/drivers/clk/rockchip/clk-mmc-phase.c b/drivers/clk/rockchip/clk-mmc-phase.c new file mode 100644 index 000000000000..c842e3b60f21 --- /dev/null +++ b/drivers/clk/rockchip/clk-mmc-phase.c @@ -0,0 +1,154 @@ +/* + * Copyright 2014 Google, Inc + * Author: Alexandru M Stan <amstan@chromium.org> + * + * 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/slab.h> +#include <linux/clk-provider.h> +#include "clk.h" + +struct rockchip_mmc_clock { + struct clk_hw hw; + void __iomem *reg; + int id; + int shift; +}; + +#define to_mmc_clock(_hw) container_of(_hw, struct rockchip_mmc_clock, hw) + +#define RK3288_MMC_CLKGEN_DIV 2 + +static unsigned long rockchip_mmc_recalc(struct clk_hw *hw, + unsigned long parent_rate) +{ + return parent_rate / RK3288_MMC_CLKGEN_DIV; +} + +#define ROCKCHIP_MMC_DELAY_SEL BIT(10) +#define ROCKCHIP_MMC_DEGREE_MASK 0x3 +#define ROCKCHIP_MMC_DELAYNUM_OFFSET 2 +#define ROCKCHIP_MMC_DELAYNUM_MASK (0xff << ROCKCHIP_MMC_DELAYNUM_OFFSET) + +#define PSECS_PER_SEC 1000000000000LL + +/* + * Each fine delay is between 40ps-80ps. Assume each fine delay is 60ps to + * simplify calculations. So 45degs could be anywhere between 33deg and 66deg. + */ +#define ROCKCHIP_MMC_DELAY_ELEMENT_PSEC 60 + +static int rockchip_mmc_get_phase(struct clk_hw *hw) +{ + struct rockchip_mmc_clock *mmc_clock = to_mmc_clock(hw); + unsigned long rate = clk_get_rate(hw->clk); + u32 raw_value; + u16 degrees; + u32 delay_num = 0; + + raw_value = readl(mmc_clock->reg) >> (mmc_clock->shift); + + degrees = (raw_value & ROCKCHIP_MMC_DEGREE_MASK) * 90; + + if (raw_value & ROCKCHIP_MMC_DELAY_SEL) { + /* degrees/delaynum * 10000 */ + unsigned long factor = (ROCKCHIP_MMC_DELAY_ELEMENT_PSEC / 10) * + 36 * (rate / 1000000); + + delay_num = (raw_value & ROCKCHIP_MMC_DELAYNUM_MASK); + delay_num >>= ROCKCHIP_MMC_DELAYNUM_OFFSET; + degrees += delay_num * factor / 10000; + } + + return degrees % 360; +} + +static int rockchip_mmc_set_phase(struct clk_hw *hw, int degrees) +{ + struct rockchip_mmc_clock *mmc_clock = to_mmc_clock(hw); + unsigned long rate = clk_get_rate(hw->clk); + u8 nineties, remainder; + u8 delay_num; + u32 raw_value; + u64 delay; + + /* allow 22 to be 22.5 */ + degrees++; + /* floor to 22.5 increment */ + degrees -= ((degrees) * 10 % 225) / 10; + + nineties = degrees / 90; + /* 22.5 multiples */ + remainder = (degrees % 90) / 22; + + delay = PSECS_PER_SEC; + do_div(delay, rate); + /* / 360 / 22.5 */ + do_div(delay, 16); + do_div(delay, ROCKCHIP_MMC_DELAY_ELEMENT_PSEC); + + delay *= remainder; + delay_num = (u8) min(delay, 255ULL); + + raw_value = delay_num ? ROCKCHIP_MMC_DELAY_SEL : 0; + raw_value |= delay_num << ROCKCHIP_MMC_DELAYNUM_OFFSET; + raw_value |= nineties; + writel(HIWORD_UPDATE(raw_value, 0x07ff, mmc_clock->shift), mmc_clock->reg); + + pr_debug("%s->set_phase(%d) delay_nums=%u reg[0x%p]=0x%03x actual_degrees=%d\n", + __clk_get_name(hw->clk), degrees, delay_num, + mmc_clock->reg, raw_value>>(mmc_clock->shift), + rockchip_mmc_get_phase(hw) + ); + + return 0; +} + +static const struct clk_ops rockchip_mmc_clk_ops = { + .recalc_rate = rockchip_mmc_recalc, + .get_phase = rockchip_mmc_get_phase, + .set_phase = rockchip_mmc_set_phase, +}; + +struct clk *rockchip_clk_register_mmc(const char *name, + const char **parent_names, u8 num_parents, + void __iomem *reg, int shift) +{ + struct clk_init_data init; + struct rockchip_mmc_clock *mmc_clock; + struct clk *clk; + + mmc_clock = kmalloc(sizeof(*mmc_clock), GFP_KERNEL); + if (!mmc_clock) + return NULL; + + init.num_parents = num_parents; + init.parent_names = parent_names; + init.ops = &rockchip_mmc_clk_ops; + + mmc_clock->hw.init = &init; + mmc_clock->reg = reg; + mmc_clock->shift = shift; + + if (name) + init.name = name; + + clk = clk_register(NULL, &mmc_clock->hw); + if (IS_ERR(clk)) + goto err_free; + + return clk; + +err_free: + kfree(mmc_clock); + return NULL; +} |