diff options
author | Tero Kristo <t-kristo@ti.com> | 2013-06-18 15:55:59 (GMT) |
---|---|---|
committer | Mike Turquette <mturquette@linaro.org> | 2014-01-17 20:35:10 (GMT) |
commit | f60b1ea5ea7ab1aee34a5ba55520b84b6e6d482e (patch) | |
tree | f7afada378e4ebac7fb02cd05adb653b4fec760d | |
parent | 1f847c65fd569c1d822800ba3e7e18c6411a7d50 (diff) | |
download | linux-f60b1ea5ea7ab1aee34a5ba55520b84b6e6d482e.tar.xz |
CLK: TI: add support for gate clock
This patch adds support for TI specific gate clocks. These behave as basic
gate-clock, but have different ops / hw-ops for controlling the actual
gate, for example waiting until the clock is ready. Several sub-types
are supported:
- ti,gate-clock: basic gate clock with default ops/hwops
- ti,clkdm-gate-clock: clockdomain level gate control
- ti,dss-gate-clock: gate clock with DSS specific hardware handling
- ti,am35xx-gate-clock: gate clock with AM35xx specific hardware handling
- ti,hsdiv-gate-clock: gate clock with OMAP36xx hardware errata handling
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
-rw-r--r-- | Documentation/devicetree/bindings/clock/ti/gate.txt | 85 | ||||
-rw-r--r-- | drivers/clk/ti/Makefile | 2 | ||||
-rw-r--r-- | drivers/clk/ti/gate.c | 249 | ||||
-rw-r--r-- | include/linux/clk/ti.h | 6 |
4 files changed, 341 insertions, 1 deletions
diff --git a/Documentation/devicetree/bindings/clock/ti/gate.txt b/Documentation/devicetree/bindings/clock/ti/gate.txt new file mode 100644 index 0000000..125281a --- /dev/null +++ b/Documentation/devicetree/bindings/clock/ti/gate.txt @@ -0,0 +1,85 @@ +Binding for Texas Instruments gate clock. + +Binding status: Unstable - ABI compatibility may be broken in the future + +This binding uses the common clock binding[1]. This clock is +quite much similar to the basic gate-clock [2], however, +it supports a number of additional features. If no register +is provided for this clock, the code assumes that a clockdomain +will be controlled instead and the corresponding hw-ops for +that is used. + +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt +[2] Documentation/devicetree/bindings/clock/gate-clock.txt +[3] Documentation/devicetree/bindings/clock/ti/clockdomain.txt + +Required properties: +- compatible : shall be one of: + "ti,gate-clock" - basic gate clock + "ti,wait-gate-clock" - gate clock which waits until clock is active before + returning from clk_enable() + "ti,dss-gate-clock" - gate clock with DSS specific hardware handling + "ti,am35xx-gate-clock" - gate clock with AM35xx specific hardware handling + "ti,clkdm-gate-clock" - clockdomain gate clock, which derives its functional + clock directly from a clockdomain, see [3] how + to map clockdomains properly + "ti,hsdiv-gate-clock" - gate clock with OMAP36xx specific hardware handling, + required for a hardware errata +- #clock-cells : from common clock binding; shall be set to 0 +- clocks : link to phandle of parent clock +- reg : offset for register controlling adjustable gate, not needed for + ti,clkdm-gate-clock type + +Optional properties: +- ti,bit-shift : bit shift for programming the clock gate, invalid for + ti,clkdm-gate-clock type +- ti,set-bit-to-disable : inverts default gate programming. Setting the bit + gates the clock and clearing the bit ungates the clock. + +Examples: + mmchs2_fck: mmchs2_fck@48004a00 { + #clock-cells = <0>; + compatible = "ti,gate-clock"; + clocks = <&core_96m_fck>; + reg = <0x48004a00 0x4>; + ti,bit-shift = <25>; + }; + + uart4_fck_am35xx: uart4_fck_am35xx { + #clock-cells = <0>; + compatible = "ti,wait-gate-clock"; + clocks = <&core_48m_fck>; + reg = <0x0a00>; + ti,bit-shift = <23>; + }; + + dss1_alwon_fck_3430es2: dss1_alwon_fck_3430es2@48004e00 { + #clock-cells = <0>; + compatible = "ti,dss-gate-clock"; + clocks = <&dpll4_m4x2_ck>; + reg = <0x48004e00 0x4>; + ti,bit-shift = <0>; + }; + + emac_ick: emac_ick@4800259c { + #clock-cells = <0>; + compatible = "ti,am35xx-gate-clock"; + clocks = <&ipss_ick>; + reg = <0x4800259c 0x4>; + ti,bit-shift = <1>; + }; + + emu_src_ck: emu_src_ck { + #clock-cells = <0>; + compatible = "ti,clkdm-gate-clock"; + clocks = <&emu_src_mux_ck>; + }; + + dpll4_m2x2_ck: dpll4_m2x2_ck@48004d00 { + #clock-cells = <0>; + compatible = "ti,hsdiv-gate-clock"; + clocks = <&dpll4_m2x2_mul_ck>; + ti,bit-shift = <0x1b>; + reg = <0x48004d00 0x4>; + ti,set-bit-to-disable; + }; diff --git a/drivers/clk/ti/Makefile b/drivers/clk/ti/Makefile index d3586252..eaa6dc0 100644 --- a/drivers/clk/ti/Makefile +++ b/drivers/clk/ti/Makefile @@ -1,5 +1,5 @@ ifneq ($(CONFIG_OF),) obj-y += clk.o autoidle.o -clk-common = dpll.o composite.o divider.o \ +clk-common = dpll.o composite.o divider.o gate.o \ fixed-factor.o endif diff --git a/drivers/clk/ti/gate.c b/drivers/clk/ti/gate.c new file mode 100644 index 0000000..3e2999d --- /dev/null +++ b/drivers/clk/ti/gate.c @@ -0,0 +1,249 @@ +/* + * OMAP gate clock support + * + * Copyright (C) 2013 Texas Instruments, Inc. + * + * Tero Kristo <t-kristo@ti.com> + * + * 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 + * published by the Free Software Foundation. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; 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/slab.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/clk/ti.h> + +#define to_clk_divider(_hw) container_of(_hw, struct clk_divider, hw) + +#undef pr_fmt +#define pr_fmt(fmt) "%s: " fmt, __func__ + +static int omap36xx_gate_clk_enable_with_hsdiv_restore(struct clk_hw *clk); + +static const struct clk_ops omap_gate_clkdm_clk_ops = { + .init = &omap2_init_clk_clkdm, + .enable = &omap2_clkops_enable_clkdm, + .disable = &omap2_clkops_disable_clkdm, +}; + +static const struct clk_ops omap_gate_clk_ops = { + .init = &omap2_init_clk_clkdm, + .enable = &omap2_dflt_clk_enable, + .disable = &omap2_dflt_clk_disable, + .is_enabled = &omap2_dflt_clk_is_enabled, +}; + +static const struct clk_ops omap_gate_clk_hsdiv_restore_ops = { + .init = &omap2_init_clk_clkdm, + .enable = &omap36xx_gate_clk_enable_with_hsdiv_restore, + .disable = &omap2_dflt_clk_disable, + .is_enabled = &omap2_dflt_clk_is_enabled, +}; + +/** + * omap36xx_gate_clk_enable_with_hsdiv_restore - enable clocks suffering + * from HSDivider PWRDN problem Implements Errata ID: i556. + * @clk: DPLL output struct clk + * + * 3630 only: dpll3_m3_ck, dpll4_m2_ck, dpll4_m3_ck, dpll4_m4_ck, + * dpll4_m5_ck & dpll4_m6_ck dividers gets loaded with reset + * valueafter their respective PWRDN bits are set. Any dummy write + * (Any other value different from the Read value) to the + * corresponding CM_CLKSEL register will refresh the dividers. + */ +static int omap36xx_gate_clk_enable_with_hsdiv_restore(struct clk_hw *clk) +{ + struct clk_divider *parent; + struct clk_hw *parent_hw; + u32 dummy_v, orig_v; + int ret; + + /* Clear PWRDN bit of HSDIVIDER */ + ret = omap2_dflt_clk_enable(clk); + + /* Parent is the x2 node, get parent of parent for the m2 div */ + parent_hw = __clk_get_hw(__clk_get_parent(__clk_get_parent(clk->clk))); + parent = to_clk_divider(parent_hw); + + /* Restore the dividers */ + if (!ret) { + orig_v = ti_clk_ll_ops->clk_readl(parent->reg); + dummy_v = orig_v; + + /* Write any other value different from the Read value */ + dummy_v ^= (1 << parent->shift); + ti_clk_ll_ops->clk_writel(dummy_v, parent->reg); + + /* Write the original divider */ + ti_clk_ll_ops->clk_writel(orig_v, parent->reg); + } + + return ret; +} + +static void __init _of_ti_gate_clk_setup(struct device_node *node, + const struct clk_ops *ops, + const struct clk_hw_omap_ops *hw_ops) +{ + struct clk *clk; + struct clk_init_data init = { NULL }; + struct clk_hw_omap *clk_hw; + const char *clk_name = node->name; + const char *parent_name; + u32 val; + + clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL); + if (!clk_hw) + return; + + clk_hw->hw.init = &init; + + init.name = clk_name; + init.ops = ops; + + if (ops != &omap_gate_clkdm_clk_ops) { + clk_hw->enable_reg = ti_clk_get_reg_addr(node, 0); + if (!clk_hw->enable_reg) + goto cleanup; + + if (!of_property_read_u32(node, "ti,bit-shift", &val)) + clk_hw->enable_bit = val; + } + + clk_hw->ops = hw_ops; + + clk_hw->flags = MEMMAP_ADDRESSING; + + if (of_clk_get_parent_count(node) != 1) { + pr_err("%s must have 1 parent\n", clk_name); + goto cleanup; + } + + parent_name = of_clk_get_parent_name(node, 0); + init.parent_names = &parent_name; + init.num_parents = 1; + + if (of_property_read_bool(node, "ti,set-rate-parent")) + init.flags |= CLK_SET_RATE_PARENT; + + if (of_property_read_bool(node, "ti,set-bit-to-disable")) + clk_hw->flags |= INVERT_ENABLE; + + clk = clk_register(NULL, &clk_hw->hw); + + if (!IS_ERR(clk)) { + of_clk_add_provider(node, of_clk_src_simple_get, clk); + return; + } + +cleanup: + kfree(clk_hw); +} + +static void __init +_of_ti_composite_gate_clk_setup(struct device_node *node, + const struct clk_hw_omap_ops *hw_ops) +{ + struct clk_hw_omap *gate; + u32 val = 0; + + gate = kzalloc(sizeof(*gate), GFP_KERNEL); + if (!gate) + return; + + gate->enable_reg = ti_clk_get_reg_addr(node, 0); + if (!gate->enable_reg) + goto cleanup; + + of_property_read_u32(node, "ti,bit-shift", &val); + + gate->enable_bit = val; + gate->ops = hw_ops; + gate->flags = MEMMAP_ADDRESSING; + + if (!ti_clk_add_component(node, &gate->hw, CLK_COMPONENT_TYPE_GATE)) + return; + +cleanup: + kfree(gate); +} + +static void __init +of_ti_composite_no_wait_gate_clk_setup(struct device_node *node) +{ + _of_ti_composite_gate_clk_setup(node, NULL); +} +CLK_OF_DECLARE(ti_composite_no_wait_gate_clk, "ti,composite-no-wait-gate-clock", + of_ti_composite_no_wait_gate_clk_setup); + +#ifdef CONFIG_ARCH_OMAP3 +static void __init of_ti_composite_interface_clk_setup(struct device_node *node) +{ + _of_ti_composite_gate_clk_setup(node, &clkhwops_iclk_wait); +} +CLK_OF_DECLARE(ti_composite_interface_clk, "ti,composite-interface-clock", + of_ti_composite_interface_clk_setup); +#endif + +static void __init of_ti_composite_gate_clk_setup(struct device_node *node) +{ + _of_ti_composite_gate_clk_setup(node, &clkhwops_wait); +} +CLK_OF_DECLARE(ti_composite_gate_clk, "ti,composite-gate-clock", + of_ti_composite_gate_clk_setup); + + +static void __init of_ti_clkdm_gate_clk_setup(struct device_node *node) +{ + _of_ti_gate_clk_setup(node, &omap_gate_clkdm_clk_ops, NULL); +} +CLK_OF_DECLARE(ti_clkdm_gate_clk, "ti,clkdm-gate-clock", + of_ti_clkdm_gate_clk_setup); + +static void __init of_ti_hsdiv_gate_clk_setup(struct device_node *node) +{ + _of_ti_gate_clk_setup(node, &omap_gate_clk_hsdiv_restore_ops, + &clkhwops_wait); +} +CLK_OF_DECLARE(ti_hsdiv_gate_clk, "ti,hsdiv-gate-clock", + of_ti_hsdiv_gate_clk_setup); + +static void __init of_ti_gate_clk_setup(struct device_node *node) +{ + _of_ti_gate_clk_setup(node, &omap_gate_clk_ops, NULL); +} +CLK_OF_DECLARE(ti_gate_clk, "ti,gate-clock", of_ti_gate_clk_setup) + +static void __init of_ti_wait_gate_clk_setup(struct device_node *node) +{ + _of_ti_gate_clk_setup(node, &omap_gate_clk_ops, &clkhwops_wait); +} +CLK_OF_DECLARE(ti_wait_gate_clk, "ti,wait-gate-clock", + of_ti_wait_gate_clk_setup); + +#ifdef CONFIG_ARCH_OMAP3 +static void __init of_ti_am35xx_gate_clk_setup(struct device_node *node) +{ + _of_ti_gate_clk_setup(node, &omap_gate_clk_ops, + &clkhwops_am35xx_ipss_module_wait); +} +CLK_OF_DECLARE(ti_am35xx_gate_clk, "ti,am35xx-gate-clock", + of_ti_am35xx_gate_clk_setup); + +static void __init of_ti_dss_gate_clk_setup(struct device_node *node) +{ + _of_ti_gate_clk_setup(node, &omap_gate_clk_ops, + &clkhwops_omap3430es2_dss_usbhost_wait); +} +CLK_OF_DECLARE(ti_dss_gate_clk, "ti,dss-gate-clock", + of_ti_dss_gate_clk_setup); +#endif diff --git a/include/linux/clk/ti.h b/include/linux/clk/ti.h index 17fb49e..d94feb3 100644 --- a/include/linux/clk/ti.h +++ b/include/linux/clk/ti.h @@ -244,6 +244,8 @@ long omap2_dpll_round_rate(struct clk_hw *hw, unsigned long target_rate, void omap2_init_clk_clkdm(struct clk_hw *clk); unsigned long omap3_clkoutx2_recalc(struct clk_hw *hw, unsigned long parent_rate); +int omap2_clkops_enable_clkdm(struct clk_hw *hw); +void omap2_clkops_disable_clkdm(struct clk_hw *hw); int omap3_dpll4_set_rate(struct clk_hw *clk, unsigned long rate, unsigned long parent_rate); int omap2_dflt_clk_enable(struct clk_hw *hw); @@ -268,5 +270,9 @@ static inline void of_ti_clk_deny_autoidle_all(void) { } extern const struct clk_hw_omap_ops clkhwops_omap3_dpll; extern const struct clk_hw_omap_ops clkhwops_omap4_dpllmx; +extern const struct clk_hw_omap_ops clkhwops_wait; +extern const struct clk_hw_omap_ops clkhwops_omap3430es2_dss_usbhost_wait; +extern const struct clk_hw_omap_ops clkhwops_am35xx_ipss_module_wait; +extern const struct clk_hw_omap_ops clkhwops_iclk_wait; #endif |