The patch adds support for TI divider clock binding. The driver uses routines provided by the common clock framework (ccf).
The code is based on the drivers/clk/ti/divider.c driver of the Linux kernel.
Signed-off-by: Dario Binacchi dariobin@libero.it ---
.../clock/ti,autoidle.txt | 39 ++ doc/device-tree-bindings/clock/ti,divider.txt | 117 +++++ drivers/clk/Kconfig | 6 + drivers/clk/Makefile | 1 + drivers/clk/clk-ti-divider.c | 403 ++++++++++++++++++ 5 files changed, 566 insertions(+) create mode 100644 doc/device-tree-bindings/clock/ti,autoidle.txt create mode 100644 doc/device-tree-bindings/clock/ti,divider.txt create mode 100644 drivers/clk/clk-ti-divider.c
diff --git a/doc/device-tree-bindings/clock/ti,autoidle.txt b/doc/device-tree-bindings/clock/ti,autoidle.txt new file mode 100644 index 0000000000..6c5b77e18c --- /dev/null +++ b/doc/device-tree-bindings/clock/ti,autoidle.txt @@ -0,0 +1,39 @@ +Binding for Texas Instruments autoidle clock. + +Binding status: Unstable - ABI compatibility may be broken in the future + +This binding uses the common clock binding[1]. It assumes a register mapped +clock which can be put to idle automatically by hardware based on the usage +and a configuration bit setting. Autoidle clock is never an individual +clock, it is always a derivative of some basic clock like a gate, divider, +or fixed-factor. + +[1] doc/device-tree-bindings/clock/clock-bindings.txt + +Required properties: +- reg : offset for the register controlling the autoidle +- ti,autoidle-shift : bit shift of the autoidle enable bit +- ti,invert-autoidle-bit : autoidle is enabled by setting the bit to 0 + +Examples: + dpll_core_m4_ck: dpll_core_m4_ck { + #clock-cells = <0>; + compatible = "ti,divider-clock"; + clocks = <&dpll_core_x2_ck>; + ti,max-div = <31>; + ti,autoidle-shift = <8>; + reg = <0x2d38>; + ti,index-starts-at-one; + ti,invert-autoidle-bit; + }; + + dpll_usb_clkdcoldo_ck: dpll_usb_clkdcoldo_ck { + #clock-cells = <0>; + compatible = "ti,fixed-factor-clock"; + clocks = <&dpll_usb_ck>; + ti,clock-div = <1>; + ti,autoidle-shift = <8>; + reg = <0x01b4>; + ti,clock-mult = <1>; + ti,invert-autoidle-bit; + }; diff --git a/doc/device-tree-bindings/clock/ti,divider.txt b/doc/device-tree-bindings/clock/ti,divider.txt new file mode 100644 index 0000000000..3d0570e915 --- /dev/null +++ b/doc/device-tree-bindings/clock/ti,divider.txt @@ -0,0 +1,117 @@ +Binding for TI divider clock + +Binding status: Unstable - ABI compatibility may be broken in the future + +This binding uses the common clock binding[1]. It assumes a +register-mapped adjustable clock rate divider that does not gate and has +only one input clock or parent. By default the value programmed into +the register is one less than the actual divisor value. E.g: + +register value actual divisor value +0 1 +1 2 +2 3 + +This assumption may be modified by the following optional properties: + +ti,index-starts-at-one - valid divisor values start at 1, not the default +of 0. E.g: +register value actual divisor value +1 1 +2 2 +3 3 + +ti,index-power-of-two - valid divisor values are powers of two. E.g: +register value actual divisor value +0 1 +1 2 +2 4 + +Additionally an array of valid dividers may be supplied like so: + + ti,dividers = <4>, <8>, <0>, <16>; + +Which will map the resulting values to a divisor table by their index: +register value actual divisor value +0 4 +1 8 +2 <invalid divisor, skipped> +3 16 + +Any zero value in this array means the corresponding bit-value is invalid +and must not be used. + +The binding must also provide the register to control the divider and +unless the divider array is provided, min and max dividers. Optionally +the number of bits to shift that mask, if necessary. If the shift value +is missing it is the same as supplying a zero shift. + +This binding can also optionally provide support to the hardware autoidle +feature, see [2]. + +[1] doc/device-tree-bindings/clock/clock/clock-bindings.txt +[2] doc/device-tree-bindings/clock/ti,autoidle.txt + +Required properties: +- compatible : shall be "ti,divider-clock" or "ti,composite-divider-clock". +- #clock-cells : from common clock binding; shall be set to 0. +- clocks : link to phandle of parent clock +- reg : offset for register controlling adjustable divider + +Optional properties: +- clock-output-names : from common clock binding. +- ti,dividers : array of integers defining divisors +- ti,bit-shift : number of bits to shift the divider value, defaults to 0 +- ti,min-div : min divisor for dividing the input clock rate, only + needed if the first divisor is offset from the default value (1) +- ti,max-div : max divisor for dividing the input clock rate, only needed + if ti,dividers is not defined. +- ti,index-starts-at-one : valid divisor programming starts at 1, not zero, + only valid if ti,dividers is not defined. +- ti,index-power-of-two : valid divisor programming must be a power of two, + only valid if ti,dividers is not defined. +- ti,autoidle-shift : bit shift of the autoidle enable bit for the clock, + see [2] +- ti,invert-autoidle-bit : autoidle is enabled by setting the bit to 0, + see [2] +- ti,set-rate-parent : clk_set_rate is propagated to parent +- ti,latch-bit : latch the divider value to HW, only needed if the register + access requires this. As an example dra76x DPLL_GMAC H14 divider implements + such behavior. + +Examples: +dpll_usb_m2_ck: dpll_usb_m2_ck@4a008190 { + #clock-cells = <0>; + compatible = "ti,divider-clock"; + clocks = <&dpll_usb_ck>; + ti,max-div = <127>; + reg = <0x190>; + ti,index-starts-at-one; +}; + +aess_fclk: aess_fclk@4a004528 { + #clock-cells = <0>; + compatible = "ti,divider-clock"; + clocks = <&abe_clk>; + ti,bit-shift = <24>; + reg = <0x528>; + ti,max-div = <2>; +}; + +dpll_core_m3x2_div_ck: dpll_core_m3x2_div_ck { + #clock-cells = <0>; + compatible = "ti,composite-divider-clock"; + clocks = <&dpll_core_x2_ck>; + ti,max-div = <31>; + reg = <0x0134>; + ti,index-starts-at-one; +}; + +ssi_ssr_div_fck_3430es2: ssi_ssr_div_fck_3430es2 { + #clock-cells = <0>; + compatible = "ti,composite-divider-clock"; + clocks = <&corex2_fck>; + ti,bit-shift = <8>; + reg = <0x0a40>; + ti,dividers = <0>, <1>, <2>, <3>, <4>, <0>, <6>, <0>, <8>; +}; diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig index bddb454b7c..d7b546d9db 100644 --- a/drivers/clk/Kconfig +++ b/drivers/clk/Kconfig @@ -105,6 +105,12 @@ config CLK_TI_AM3_DPLL This enables the DPLL clock drivers support on AM33XX SoCs. The DPLL provides all interface clocks and functional clocks to the processor.
+config CLK_TI_DIVIDER + bool "TI divider clock driver" + depends on CLK && OF_CONTROL && CLK_CCF + help + This enables the divider clock driver support on TI's SoCs. + config CLK_TI_MUX bool "TI mux clock driver" depends on CLK && OF_CONTROL && CLK_CCF diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index cc20279a20..0fcfcc1837 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -47,6 +47,7 @@ obj-$(CONFIG_SANDBOX) += clk_sandbox_test.o obj-$(CONFIG_SANDBOX_CLK_CCF) += clk_sandbox_ccf.o obj-$(CONFIG_STM32H7) += clk_stm32h7.o obj-$(CONFIG_CLK_TI_AM3_DPLL) += clk-ti-am3-dpll.o clk-ti-am3-dpll-x2.o +obj-$(CONFIG_CLK_TI_DIVIDER) += clk-ti-divider.o obj-$(CONFIG_CLK_TI_MUX) += clk-ti-mux.o obj-$(CONFIG_CLK_TI_SCI) += clk-ti-sci.o obj-$(CONFIG_CLK_VERSAL) += clk_versal.o diff --git a/drivers/clk/clk-ti-divider.c b/drivers/clk/clk-ti-divider.c new file mode 100644 index 0000000000..fa9d60a2d5 --- /dev/null +++ b/drivers/clk/clk-ti-divider.c @@ -0,0 +1,403 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * TI divider clock support + * + * Copyright (C) 2020 Dario Binacchi dariobin@libero.it + * + * Loosely based on Linux kernel drivers/clk/ti/divider.c + */ + +#include <common.h> +#include <clk.h> +#include <clk-uclass.h> +#include <div64.h> +#include <dm.h> +#include <asm/io.h> +#include <linux/clk-provider.h> +#include <linux/kernel.h> +#include <linux/log2.h> + +/* + * The reverse of DIV_ROUND_UP: The maximum number which + * divided by m is r + */ +#define MULT_ROUND_UP(r, m) ((r) * (m) + (m) - 1) + +struct clk_ti_divider_priv { + struct clk parent; + fdt_addr_t reg; + const struct clk_div_table *table; + u8 shift; + u8 flags; + u8 div_flags; + s8 latch; + u16 min; + u16 max; + u16 mask; +}; + +static void clk_ti_divider_rmw(u32 val, u32 mask, fdt_addr_t reg) +{ + u32 v; + + v = readl(reg); + v &= ~mask; + v |= val; + writel(v, reg); +} + +static void clk_ti_divider_latch(fdt_addr_t reg, s8 shift) +{ + u32 latch; + + if (shift < 0) + return; + + latch = 1 << shift; + + clk_ti_divider_rmw(latch, latch, reg); + clk_ti_divider_rmw(0, latch, reg); + readl(reg); /* OCP barrier */ +} + +static unsigned int _get_div(const struct clk_div_table *table, ulong flags, + unsigned int val) +{ + if (flags & CLK_DIVIDER_ONE_BASED) + return val; + + if (flags & CLK_DIVIDER_POWER_OF_TWO) + return 1 << val; + + if (table) + return divider_get_table_div(table, val); + + return val + 1; +} + +static unsigned int _get_val(const struct clk_div_table *table, ulong flags, + unsigned int div) +{ + if (flags & CLK_DIVIDER_ONE_BASED) + return div; + + if (flags & CLK_DIVIDER_POWER_OF_TWO) + return __ffs(div); + + if (table) + return divider_get_table_val(table, div); + + return div - 1; +} + +static int _div_round_up(const struct clk_div_table *table, ulong parent_rate, + ulong rate) +{ + const struct clk_div_table *clkt; + int up = INT_MAX; + int div = DIV_ROUND_UP_ULL((u64)parent_rate, rate); + + for (clkt = table; clkt->div; clkt++) { + if (clkt->div == div) + return clkt->div; + else if (clkt->div < div) + continue; + + if ((clkt->div - div) < (up - div)) + up = clkt->div; + } + + return up; +} + +static int _div_round(const struct clk_div_table *table, ulong parent_rate, + ulong rate) +{ + if (table) + return _div_round_up(table, parent_rate, rate); + + return DIV_ROUND_UP(parent_rate, rate); +} + +static int clk_ti_divider_best_div(struct clk *clk, ulong rate, + ulong *best_parent_rate) +{ + struct clk_ti_divider_priv *priv = dev_get_priv(clk->dev); + ulong parent_rate, parent_round_rate, max_div; + ulong best_rate, r; + int i, best_div = 0; + + parent_rate = clk_get_rate(&priv->parent); + if (IS_ERR_VALUE(parent_rate)) + return parent_rate; + + if (!rate) + rate = 1; + + if (!(clk->flags & CLK_SET_RATE_PARENT)) { + best_div = _div_round(priv->table, parent_rate, rate); + if (best_div == 0) + best_div = 1; + + if (best_div > priv->max) + best_div = priv->max; + + *best_parent_rate = parent_rate; + return best_div; + } + + max_div = min(ULONG_MAX / rate, (ulong)priv->max); + for (best_rate = 0, i = 1; i <= max_div; i++) { + if (!divider_is_valid_div(priv->table, priv->div_flags, i)) + continue; + + /* + * It's the most ideal case if the requested rate can be + * divided from parent clock without needing to change + * parent rate, so return the divider immediately. + */ + if ((rate * i) == parent_rate) { + *best_parent_rate = parent_rate; + dev_dbg(dev, "rate=%ld, best_rate=%ld, div=%d\n", rate, + rate, i); + return i; + } + + parent_round_rate = clk_round_rate(&priv->parent, + MULT_ROUND_UP(rate, i)); + if (IS_ERR_VALUE(parent_round_rate)) + continue; + + r = DIV_ROUND_UP(parent_round_rate, i); + if (r <= rate && r > best_rate) { + best_div = i; + best_rate = r; + *best_parent_rate = parent_round_rate; + if (best_rate == rate) + break; + } + } + + if (best_div == 0) { + best_div = priv->max; + parent_round_rate = clk_round_rate(&priv->parent, 1); + if (IS_ERR_VALUE(parent_round_rate)) + return parent_round_rate; + } + + dev_dbg(dev, "rate=%ld, best_rate=%ld, div=%d\n", rate, best_rate, + best_div); + + return best_div; +} + +static ulong clk_ti_divider_round_rate(struct clk *clk, ulong rate) +{ + ulong parent_rate; + int div; + + div = clk_ti_divider_best_div(clk, rate, &parent_rate); + if (div < 0) + return div; + + return DIV_ROUND_UP(parent_rate, div); +} + +static ulong clk_ti_divider_set_rate(struct clk *clk, ulong rate) +{ + struct clk_ti_divider_priv *priv = dev_get_priv(clk->dev); + ulong parent_rate; + int div; + u32 val, v; + + div = clk_ti_divider_best_div(clk, rate, &parent_rate); + if (div < 0) + return div; + + if (clk->flags & CLK_SET_RATE_PARENT) { + parent_rate = clk_set_rate(&priv->parent, parent_rate); + if (IS_ERR_VALUE(parent_rate)) + return parent_rate; + } + + val = _get_val(priv->table, priv->div_flags, div); + + v = readl(priv->reg); + v &= ~(priv->mask << priv->shift); + v |= val << priv->shift; + writel(v, priv->reg); + clk_ti_divider_latch(priv->reg, priv->latch); + + return clk_get_rate(clk); +} + +static ulong clk_ti_divider_get_rate(struct clk *clk) +{ + struct clk_ti_divider_priv *priv = dev_get_priv(clk->dev); + ulong rate, parent_rate; + unsigned int div; + u32 v; + + parent_rate = clk_get_rate(&priv->parent); + if (IS_ERR_VALUE(parent_rate)) + return parent_rate; + + v = readl(priv->reg) >> priv->shift; + v &= priv->mask; + + div = _get_div(priv->table, priv->div_flags, v); + if (!div) { + if (!(priv->div_flags & CLK_DIVIDER_ALLOW_ZERO)) + dev_warn(clk->dev, + "zero divisor and CLK_DIVIDER_ALLOW_ZERO not set\n"); + return parent_rate; + } + + rate = DIV_ROUND_UP(parent_rate, div); + dev_dbg(clk->dev, "rate=%ld\n", rate); + return rate; +} + +static int clk_ti_divider_request(struct clk *clk) +{ + struct clk_ti_divider_priv *priv = dev_get_priv(clk->dev); + + clk->flags = priv->flags; + return 0; +} + +const struct clk_ops clk_ti_divider_ops = { + .request = clk_ti_divider_request, + .round_rate = clk_ti_divider_round_rate, + .get_rate = clk_ti_divider_get_rate, + .set_rate = clk_ti_divider_set_rate +}; + +static int clk_ti_divider_remove(struct udevice *dev) +{ + struct clk_ti_divider_priv *priv = dev_get_priv(dev); + int err; + + err = clk_release_all(&priv->parent, 1); + if (err) { + dev_err(dev, "failed to release parent clock\n"); + return err; + } + + return 0; +} + +static int clk_ti_divider_probe(struct udevice *dev) +{ + struct clk_ti_divider_priv *priv = dev_get_priv(dev); + int err; + + err = clk_get_by_index(dev, 0, &priv->parent); + if (err) { + dev_err(dev, "failed to get parent clock\n"); + return err; + } + + return 0; +} + +static int clk_ti_divider_ofdata_to_platdata(struct udevice *dev) +{ + struct clk_ti_divider_priv *priv = dev_get_priv(dev); + struct clk_div_table *table = NULL; + u32 val, valid_div; + u32 min_div = 0; + u32 max_val, max_div = 0; + u16 mask; + int i, div_num; + + priv->reg = dev_read_addr(dev); + dev_dbg(dev, "reg=0x%08lx\n", priv->reg); + priv->shift = dev_read_u32_default(dev, "ti,bit-shift", 0); + priv->latch = dev_read_s32_default(dev, "ti,latch-bit", -EINVAL); + if (dev_read_bool(dev, "ti,index-starts-at-one")) + priv->div_flags |= CLK_DIVIDER_ONE_BASED; + + if (dev_read_bool(dev, "ti,index-power-of-two")) + priv->div_flags |= CLK_DIVIDER_POWER_OF_TWO; + + if (dev_read_bool(dev, "ti,set-rate-parent")) + priv->flags |= CLK_SET_RATE_PARENT; + + if (dev_read_prop(dev, "ti,dividers", &div_num)) { + div_num /= sizeof(u32); + + /* Determine required size for divider table */ + for (i = 0, valid_div = 0; i < div_num; i++) { + dev_read_u32_index(dev, "ti,dividers", i, &val); + if (val) + valid_div++; + } + + if (!valid_div) { + dev_err(dev, "no valid dividers\n"); + return -EINVAL; + } + + table = calloc(valid_div + 1, sizeof(*table)); + if (!table) + return -ENOMEM; + + for (i = 0, valid_div = 0; i < div_num; i++) { + dev_read_u32_index(dev, "ti,dividers", i, &val); + if (!val) + continue; + + table[valid_div].div = val; + table[valid_div].val = i; + valid_div++; + if (val > max_div) + max_div = val; + + if (!min_div || val < min_div) + min_div = val; + } + + max_val = max_div; + } else { + /* Divider table not provided, determine min/max divs */ + min_div = dev_read_u32_default(dev, "ti,min-div", 1); + if (dev_read_u32(dev, "ti,max-div", &max_div)) { + dev_err(dev, "missing 'max-div' property\n"); + return -EFAULT; + } + + max_val = max_div; + if (!(priv->div_flags & CLK_DIVIDER_ONE_BASED) && + !(priv->div_flags & CLK_DIVIDER_POWER_OF_TWO)) + max_val--; + } + + priv->table = table; + priv->min = min_div; + priv->max = max_div; + + if (priv->div_flags & CLK_DIVIDER_POWER_OF_TWO) + mask = fls(max_val) - 1; + else + mask = max_val; + + priv->mask = (1 << fls(mask)) - 1; + return 0; +} + +static const struct udevice_id clk_ti_divider_of_match[] = { + {.compatible = "ti,divider-clock"}, + {} +}; + +U_BOOT_DRIVER(clk_ti_divider) = { + .name = "ti_divider_clock", + .id = UCLASS_CLK, + .of_match = clk_ti_divider_of_match, + .ofdata_to_platdata = clk_ti_divider_ofdata_to_platdata, + .probe = clk_ti_divider_probe, + .remove = clk_ti_divider_remove, + .priv_auto_alloc_size = sizeof(struct clk_ti_divider_priv), + .ops = &clk_ti_divider_ops, +};