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 version 5.9-rc7. For DT binding details see: - Documentation/devicetree/bindings/clock/ti/dpll.txt
Signed-off-by: Dario Binacchi dariobin@libero.it
---
(no changes since v5)
Changes in v5: - Move the clk-ti-am3-dpll.c file to drivers/clk/ti with the name clk-am3-dpll.c. - Move the clk-ti-am3-dpll-x2.c file to drivers/clk/ti with the name clk-am3-dpll-x2.c.
Changes in v4: - Include device_compat.h header for dev_xxx macros. - Fix compilation errors on the dev parameter of the dev_xx macros.
Changes in v3: - Remove doc/device-tree-bindings/clock/ti,dpll.txt. - Add to commit message the references to linux kernel dt binding documentation.
drivers/clk/ti/Kconfig | 7 + drivers/clk/ti/Makefile | 1 + drivers/clk/ti/clk-am3-dpll-x2.c | 79 +++++++++ drivers/clk/ti/clk-am3-dpll.c | 268 +++++++++++++++++++++++++++++++ 4 files changed, 355 insertions(+) create mode 100644 drivers/clk/ti/clk-am3-dpll-x2.c create mode 100644 drivers/clk/ti/clk-am3-dpll.c
diff --git a/drivers/clk/ti/Kconfig b/drivers/clk/ti/Kconfig index be4f26817f..c430dd9b8a 100644 --- a/drivers/clk/ti/Kconfig +++ b/drivers/clk/ti/Kconfig @@ -3,6 +3,13 @@ # Copyright (C) 2020 Dario Binacchi dariobin@libero.it #
+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/ti/Makefile b/drivers/clk/ti/Makefile index 5faf68d30e..9e14b83cfe 100644 --- a/drivers/clk/ti/Makefile +++ b/drivers/clk/ti/Makefile @@ -3,4 +3,5 @@ # Copyright (C) 2020 Dario Binacchi dariobin@libero.it #
+obj-$(CONFIG_CLK_TI_AM3_DPLL) += clk-am3-dpll.o clk-am3-dpll-x2.o obj-$(CONFIG_CLK_TI_MUX) += clk-mux.o diff --git a/drivers/clk/ti/clk-am3-dpll-x2.c b/drivers/clk/ti/clk-am3-dpll-x2.c new file mode 100644 index 0000000000..3aa35f0e6c --- /dev/null +++ b/drivers/clk/ti/clk-am3-dpll-x2.c @@ -0,0 +1,79 @@ +// 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 <dm/device_compat.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/ti/clk-am3-dpll.c b/drivers/clk/ti/clk-am3-dpll.c new file mode 100644 index 0000000000..d50660aae2 --- /dev/null +++ b/drivers/clk/ti/clk-am3-dpll.c @@ -0,0 +1,268 @@ +// 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 <dm/device_compat.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(clk->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(clk->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, +};