The digital phase-locked loop (DPLL) provides all interface clocks and functional clocks to the processor of the AM33xx device. The AM33xx device integrates five different DPLLs: * Core DPLL * Per DPLL * LCD DPLL * DDR DPLL * MPU DPLL
The patch adds support for the compatible strings: * "ti,am3-dpll-core-clock" * "ti,am3-dpll-no-gate-clock" * "ti,am3-dpll-no-gate-j-type-clock" * "ti,am3-dpll-x2-clock"
The code is loosely based on the drivers/clk/ti/dpll.c drivers of the Linux kernel.
Signed-off-by: Dario Binacchi dariobin@libero.it ---
(no changes since v1)
doc/device-tree-bindings/clock/ti,dpll.txt | 85 +++++++ drivers/clk/Kconfig | 7 + drivers/clk/Makefile | 1 + drivers/clk/clk-ti-am3-dpll-x2.c | 78 ++++++ drivers/clk/clk-ti-am3-dpll.c | 267 +++++++++++++++++++++ 5 files changed, 438 insertions(+) create mode 100644 doc/device-tree-bindings/clock/ti,dpll.txt create mode 100644 drivers/clk/clk-ti-am3-dpll-x2.c create mode 100644 drivers/clk/clk-ti-am3-dpll.c
diff --git a/doc/device-tree-bindings/clock/ti,dpll.txt b/doc/device-tree-bindings/clock/ti,dpll.txt new file mode 100644 index 0000000000..a807b09241 --- /dev/null +++ b/doc/device-tree-bindings/clock/ti,dpll.txt @@ -0,0 +1,85 @@ +Binding for Texas Instruments DPLL 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 DPLL with usually two selectable input clocks +(reference clock and bypass clock), with digital phase locked +loop logic for multiplying the input clock to a desired output +clock. This clock also typically supports different operation +modes (locked, low power stop etc.) This binding has several +sub-types, which effectively result in slightly different setup +for the actual DPLL clock. + +[1] doc/device-tree-bindings/clock/clock-bindings.txt + +Required properties: +- compatible : shall be one of: + "ti,omap3-dpll-clock", + "ti,omap3-dpll-core-clock", + "ti,omap3-dpll-per-clock", + "ti,omap3-dpll-per-j-type-clock", + "ti,omap4-dpll-clock", + "ti,omap4-dpll-x2-clock", + "ti,omap4-dpll-core-clock", + "ti,omap4-dpll-m4xen-clock", + "ti,omap4-dpll-j-type-clock", + "ti,omap5-mpu-dpll-clock", + "ti,am3-dpll-no-gate-clock", + "ti,am3-dpll-j-type-clock", + "ti,am3-dpll-no-gate-j-type-clock", + "ti,am3-dpll-clock", + "ti,am3-dpll-core-clock", + "ti,am3-dpll-x2-clock", + "ti,omap2-dpll-core-clock", + +- #clock-cells : from common clock binding; shall be set to 0. +- clocks : link phandles of parent clocks, first entry lists reference clock + and second entry bypass clock +- reg : offsets for the register set for controlling the DPLL. + Registers are listed in following order: + "control" - contains the control register base address + "idlest" - contains the idle status register base address + "mult-div1" - contains the multiplier / divider register base address + "autoidle" - contains the autoidle register base address (optional) + ti,am3-* dpll types do not have autoidle register + ti,omap2-* dpll type does not support idlest / autoidle registers + +Optional properties: +- DPLL mode setting - defining any one or more of the following overrides + default setting. + - ti,low-power-stop : DPLL supports low power stop mode, gating output + - ti,low-power-bypass : DPLL output matches rate of parent bypass clock + - ti,lock : DPLL locks in programmed rate + +Examples: + dpll_core_ck: dpll_core_ck@44e00490 { + #clock-cells = <0>; + compatible = "ti,omap4-dpll-core-clock"; + clocks = <&sys_clkin_ck>, <&sys_clkin_ck>; + reg = <0x490>, <0x45c>, <0x488>, <0x468>; + }; + + dpll2_ck: dpll2_ck@48004004 { + #clock-cells = <0>; + compatible = "ti,omap3-dpll-clock"; + clocks = <&sys_ck>, <&dpll2_fck>; + ti,low-power-stop; + ti,low-power-bypass; + ti,lock; + reg = <0x4>, <0x24>, <0x34>, <0x40>; + }; + + dpll_core_ck: dpll_core_ck@44e00490 { + #clock-cells = <0>; + compatible = "ti,am3-dpll-core-clock"; + clocks = <&sys_clkin_ck>, <&sys_clkin_ck>; + reg = <0x90>, <0x5c>, <0x68>; + }; + + dpll_ck: dpll_ck { + #clock-cells = <0>; + compatible = "ti,omap2-dpll-core-clock"; + clocks = <&sys_ck>, <&sys_ck>; + reg = <0x0500>, <0x0540>; + }; diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig index f070d2637f..bddb454b7c 100644 --- a/drivers/clk/Kconfig +++ b/drivers/clk/Kconfig @@ -98,6 +98,13 @@ config CLK_STM32F This clock driver adds support for RCC clock management for STM32F4 and STM32F7 SoCs.
+config CLK_TI_AM3_DPLL + bool "TI AM33XX Digital Phase-Locked Loop (DPLL) clock drivers" + depends on CLK && OF_CONTROL + help + 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_MUX bool "TI mux clock driver" depends on CLK && OF_CONTROL && CLK_CCF diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index c0dfe4b599..cc20279a20 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -46,6 +46,7 @@ obj-$(CONFIG_SANDBOX) += clk_sandbox.o obj-$(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_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-am3-dpll-x2.c b/drivers/clk/clk-ti-am3-dpll-x2.c new file mode 100644 index 0000000000..c8dedbe1f8 --- /dev/null +++ b/drivers/clk/clk-ti-am3-dpll-x2.c @@ -0,0 +1,78 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * TI DPLL x2 clock support + * + * Copyright (C) 2020 Dario Binacchi dariobin@libero.it + * + * Loosely based on Linux kernel drivers/clk/ti/dpll.c + */ + +#include <common.h> +#include <clk-uclass.h> +#include <dm.h> +#include <linux/clk-provider.h> + +struct clk_ti_am3_dpll_x2_priv { + struct clk parent; +}; + +static ulong clk_ti_am3_dpll_x2_get_rate(struct clk *clk) +{ + struct clk_ti_am3_dpll_x2_priv *priv = dev_get_priv(clk->dev); + unsigned long rate; + + rate = clk_get_rate(&priv->parent); + if (IS_ERR_VALUE(rate)) + return rate; + + rate *= 2; + dev_dbg(clk->dev, "rate=%ld\n", rate); + return rate; +} + +const struct clk_ops clk_ti_am3_dpll_x2_ops = { + .get_rate = clk_ti_am3_dpll_x2_get_rate, +}; + +static int clk_ti_am3_dpll_x2_remove(struct udevice *dev) +{ + struct clk_ti_am3_dpll_x2_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_am3_dpll_x2_probe(struct udevice *dev) +{ + struct clk_ti_am3_dpll_x2_priv *priv = dev_get_priv(dev); + int err; + + err = clk_get_by_index(dev, 0, &priv->parent); + if (err) { + dev_err(dev, "%s: failed to get parent clock\n", __func__); + return err; + } + + return 0; +} + +static const struct udevice_id clk_ti_am3_dpll_x2_of_match[] = { + {.compatible = "ti,am3-dpll-x2-clock"}, + {} +}; + +U_BOOT_DRIVER(clk_ti_am3_dpll_x2) = { + .name = "ti_am3_dpll_x2_clock", + .id = UCLASS_CLK, + .of_match = clk_ti_am3_dpll_x2_of_match, + .probe = clk_ti_am3_dpll_x2_probe, + .remove = clk_ti_am3_dpll_x2_remove, + .priv_auto_alloc_size = sizeof(struct clk_ti_am3_dpll_x2_priv), + .ops = &clk_ti_am3_dpll_x2_ops, +}; diff --git a/drivers/clk/clk-ti-am3-dpll.c b/drivers/clk/clk-ti-am3-dpll.c new file mode 100644 index 0000000000..75739f991f --- /dev/null +++ b/drivers/clk/clk-ti-am3-dpll.c @@ -0,0 +1,267 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * TI DPLL clock support + * + * Copyright (C) 2020 Dario Binacchi dariobin@libero.it + * + * Loosely based on Linux kernel drivers/clk/ti/dpll.c + */ + +#include <common.h> +#include <clk.h> +#include <clk-uclass.h> +#include <div64.h> +#include <dm.h> +#include <hang.h> +#include <asm/arch/clock.h> +#include <asm/arch/sys_proto.h> +#include <asm/io.h> + +struct clk_ti_am3_dpll_drv_data { + ulong max_rate; +}; + +struct clk_ti_am3_dpll_priv { + fdt_addr_t clkmode_reg; + fdt_addr_t idlest_reg; + fdt_addr_t clksel_reg; + struct clk clk_bypass; + struct clk clk_ref; + u16 last_rounded_mult; + u8 last_rounded_div; + ulong max_rate; +}; + +static ulong clk_ti_am3_dpll_round_rate(struct clk *clk, ulong rate) +{ + struct clk_ti_am3_dpll_priv *priv = dev_get_priv(clk->dev); + ulong ret, ref_rate, r; + int m, d, err_min, err; + int mult = INT_MAX, div = INT_MAX; + + if (priv->max_rate && rate > priv->max_rate) { + dev_warn(dev, "%ld is to high a rate, lowered to %ld\n", rate, + priv->max_rate); + rate = priv->max_rate; + } + + ret = -EFAULT; + err = rate; + err_min = rate; + ref_rate = clk_get_rate(&priv->clk_ref); + for (d = 1; err_min && d <= 128; d++) { + for (m = 2; m <= 2047; m++) { + r = (ref_rate * m) / d; + err = abs(r - rate); + if (err < err_min) { + err_min = err; + ret = r; + mult = m; + div = d; + + if (err == 0) + break; + } else if (r > rate) { + break; + } + } + } + + priv->last_rounded_mult = mult; + priv->last_rounded_div = div; + dev_dbg(dev, "rate=%ld, best_rate=%ld, mult=%d, div=%d\n", rate, ret, + mult, div); + return ret; +} + +static ulong clk_ti_am3_dpll_set_rate(struct clk *clk, ulong rate) +{ + struct clk_ti_am3_dpll_priv *priv = dev_get_priv(clk->dev); + u32 v; + ulong round_rate; + + round_rate = clk_ti_am3_dpll_round_rate(clk, rate); + if (IS_ERR_VALUE(round_rate)) + return round_rate; + + v = readl(priv->clksel_reg); + + /* enter bypass mode */ + clrsetbits_le32(priv->clkmode_reg, CM_CLKMODE_DPLL_DPLL_EN_MASK, + DPLL_EN_MN_BYPASS << CM_CLKMODE_DPLL_EN_SHIFT); + + /* wait for bypass mode */ + if (!wait_on_value(ST_DPLL_CLK_MASK, 0, + (void *)priv->idlest_reg, LDELAY)) + dev_err(clk->dev, "failed bypassing dpll\n"); + + /* set M & N */ + v &= ~CM_CLKSEL_DPLL_M_MASK; + v |= (priv->last_rounded_mult << CM_CLKSEL_DPLL_M_SHIFT) & + CM_CLKSEL_DPLL_M_MASK; + + v &= ~CM_CLKSEL_DPLL_N_MASK; + v |= ((priv->last_rounded_div - 1) << CM_CLKSEL_DPLL_N_SHIFT) & + CM_CLKSEL_DPLL_N_MASK; + + writel(v, priv->clksel_reg); + + /* lock dpll */ + clrsetbits_le32(priv->clkmode_reg, CM_CLKMODE_DPLL_DPLL_EN_MASK, + DPLL_EN_LOCK << CM_CLKMODE_DPLL_EN_SHIFT); + + /* wait till the dpll locks */ + if (!wait_on_value(ST_DPLL_CLK_MASK, ST_DPLL_CLK_MASK, + (void *)priv->idlest_reg, LDELAY)) { + dev_err(clk->dev, "failed locking dpll\n"); + hang(); + } + + return round_rate; +} + +static ulong clk_ti_am3_dpll_get_rate(struct clk *clk) +{ + struct clk_ti_am3_dpll_priv *priv = dev_get_priv(clk->dev); + u64 rate; + u32 m, n, v; + + /* Return bypass rate if DPLL is bypassed */ + v = readl(priv->clkmode_reg); + v &= CM_CLKMODE_DPLL_EN_MASK; + v >>= CM_CLKMODE_DPLL_EN_SHIFT; + + switch (v) { + case DPLL_EN_MN_BYPASS: + case DPLL_EN_LOW_POWER_BYPASS: + case DPLL_EN_FAST_RELOCK_BYPASS: + rate = clk_get_rate(&priv->clk_bypass); + dev_dbg(clk->dev, "rate=%lld\n", rate); + return rate; + } + + v = readl(priv->clksel_reg); + m = v & CM_CLKSEL_DPLL_M_MASK; + m >>= CM_CLKSEL_DPLL_M_SHIFT; + n = v & CM_CLKSEL_DPLL_N_MASK; + n >>= CM_CLKSEL_DPLL_N_SHIFT; + + rate = clk_get_rate(&priv->clk_ref) * m; + do_div(rate, n + 1); + dev_dbg(clk->dev, "rate=%lld\n", rate); + return rate; +} + +const struct clk_ops clk_ti_am3_dpll_ops = { + .round_rate = clk_ti_am3_dpll_round_rate, + .get_rate = clk_ti_am3_dpll_get_rate, + .set_rate = clk_ti_am3_dpll_set_rate, +}; + +static int clk_ti_am3_dpll_remove(struct udevice *dev) +{ + struct clk_ti_am3_dpll_priv *priv = dev_get_priv(dev); + int err; + + err = clk_release_all(&priv->clk_bypass, 1); + if (err) { + dev_err(dev, "failed to release bypass clock\n"); + return err; + } + + err = clk_release_all(&priv->clk_ref, 1); + if (err) { + dev_err(dev, "failed to release reference clock\n"); + return err; + } + + return 0; +} + +static int clk_ti_am3_dpll_probe(struct udevice *dev) +{ + struct clk_ti_am3_dpll_priv *priv = dev_get_priv(dev); + int err; + + err = clk_get_by_index(dev, 0, &priv->clk_ref); + if (err) { + dev_err(dev, "failed to get reference clock\n"); + return err; + } + + err = clk_get_by_index(dev, 1, &priv->clk_bypass); + if (err) { + dev_err(dev, "failed to get bypass clock\n"); + return err; + } + + return 0; +} + +static int clk_ti_am3_dpll_ofdata_to_platdata(struct udevice *dev) +{ + struct clk_ti_am3_dpll_priv *priv = dev_get_priv(dev); + struct clk_ti_am3_dpll_drv_data *data = + (struct clk_ti_am3_dpll_drv_data *)dev_get_driver_data(dev); + + priv->max_rate = data->max_rate; + + priv->clkmode_reg = dev_read_addr_index(dev, 0); + if (priv->clkmode_reg == FDT_ADDR_T_NONE) { + dev_err(dev, "failed to get clkmode register\n"); + return -EINVAL; + } + + dev_dbg(dev, "clkmode_reg=0x%08lx\n", priv->clkmode_reg); + + priv->idlest_reg = dev_read_addr_index(dev, 1); + if (priv->idlest_reg == FDT_ADDR_T_NONE) { + dev_err(dev, "failed to get idlest register\n"); + return -EINVAL; + } + + dev_dbg(dev, "idlest_reg=0x%08lx\n", priv->idlest_reg); + + priv->clksel_reg = dev_read_addr_index(dev, 2); + if (priv->clksel_reg == FDT_ADDR_T_NONE) { + dev_err(dev, "failed to get clksel register\n"); + return -EINVAL; + } + + dev_dbg(dev, "clksel_reg=0x%08lx\n", priv->clksel_reg); + + return 0; +} + +static const struct clk_ti_am3_dpll_drv_data dpll_no_gate_data = { + .max_rate = 1000000000 +}; + +static const struct clk_ti_am3_dpll_drv_data dpll_no_gate_j_type_data = { + .max_rate = 2000000000 +}; + +static const struct clk_ti_am3_dpll_drv_data dpll_core_data = { + .max_rate = 1000000000 +}; + +static const struct udevice_id clk_ti_am3_dpll_of_match[] = { + {.compatible = "ti,am3-dpll-core-clock", + .data = (ulong)&dpll_core_data}, + {.compatible = "ti,am3-dpll-no-gate-clock", + .data = (ulong)&dpll_no_gate_data}, + {.compatible = "ti,am3-dpll-no-gate-j-type-clock", + .data = (ulong)&dpll_no_gate_j_type_data}, + {} +}; + +U_BOOT_DRIVER(clk_ti_am3_dpll) = { + .name = "ti_am3_dpll_clock", + .id = UCLASS_CLK, + .of_match = clk_ti_am3_dpll_of_match, + .ofdata_to_platdata = clk_ti_am3_dpll_ofdata_to_platdata, + .probe = clk_ti_am3_dpll_probe, + .remove = clk_ti_am3_dpll_remove, + .priv_auto_alloc_size = sizeof(struct clk_ti_am3_dpll_priv), + .ops = &clk_ti_am3_dpll_ops, +};