Add CBF clock driver as a part of MSM8996 CPU clocks. Significantly based on AngeloGioacchino del Regno's work at [1]. The CBF is an interconnect between two CPU clusters, setting it up properly is required for booting the MSM8996 with all four cores enabled. [1] https://github.com/sonyxperiadev/kernel/blob/aosp/LE.UM.2.3.2.r1.4/drivers/clk/qcom/clk-cpu-8996.c Co-developed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxx> Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxx> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> --- drivers/clk/qcom/Makefile | 2 +- drivers/clk/qcom/clk-cbf-8996.c | 318 ++++++++++++++++++++++++++++++++ 2 files changed, 319 insertions(+), 1 deletion(-) create mode 100644 drivers/clk/qcom/clk-cbf-8996.c diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile index ca2f586edb3e..d6ecd2bf7040 100644 --- a/drivers/clk/qcom/Makefile +++ b/drivers/clk/qcom/Makefile @@ -52,7 +52,7 @@ obj-$(CONFIG_MSM_MMCC_8998) += mmcc-msm8998.o obj-$(CONFIG_QCOM_A53PLL) += a53-pll.o obj-$(CONFIG_QCOM_A7PLL) += a7-pll.o obj-$(CONFIG_QCOM_CLK_APCS_MSM8916) += apcs-msm8916.o -obj-$(CONFIG_QCOM_CLK_APCC_MSM8996) += apcs-msm8996.o clk-cpu-8996.o +obj-$(CONFIG_QCOM_CLK_APCC_MSM8996) += apcs-msm8996.o clk-cpu-8996.o clk-cbf-8996.o obj-$(CONFIG_QCOM_CLK_APCS_SDX55) += apcs-sdx55.o obj-$(CONFIG_QCOM_CLK_RPM) += clk-rpm.o obj-$(CONFIG_QCOM_CLK_RPMH) += clk-rpmh.o diff --git a/drivers/clk/qcom/clk-cbf-8996.c b/drivers/clk/qcom/clk-cbf-8996.c new file mode 100644 index 000000000000..bdd4f8b48a7e --- /dev/null +++ b/drivers/clk/qcom/clk-cbf-8996.c @@ -0,0 +1,318 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2022, Linaro Ltd. + */ +#include <linux/bitfield.h> +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/of.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +#include "clk-alpha-pll.h" +#include "clk-regmap.h" + +/* Need to match the order of clocks in DT binding */ +enum { + DT_XO, + DT_APCS_AUX, +}; + +enum { + CBF_XO_INDEX, + CBF_PLL_INDEX, + CBF_DIV_INDEX, + CBF_APCS_AUX_INDEX, +}; + +#define DIV_THRESHOLD 600000000 + +#define CBF_MUX_OFFSET 0x18 +#define CBF_MUX_PARENT_MASK GENMASK(1, 0) +#define CBF_MUX_AUTO_CLK_SEL_ALWAYS_ON_MASK GENMASK(5, 4) +#define CBF_MUX_AUTO_CLK_SEL_ALWAYS_ON_GPLL0_SEL \ + FIELD_PREP(CBF_MUX_AUTO_CLK_SEL_ALWAYS_ON_MASK, 0x03) +#define CBF_MUX_AUTO_CLK_SEL_BIT BIT(6) + +#define CBF_PLL_OFFSET 0xf000 + +static const u8 cbf_pll_regs[PLL_OFF_MAX_REGS] = { + [PLL_OFF_L_VAL] = 0x08, + [PLL_OFF_ALPHA_VAL] = 0x10, + [PLL_OFF_USER_CTL] = 0x18, + [PLL_OFF_CONFIG_CTL] = 0x20, + [PLL_OFF_CONFIG_CTL_U] = 0x24, + [PLL_OFF_TEST_CTL] = 0x30, + [PLL_OFF_TEST_CTL_U] = 0x34, + [PLL_OFF_STATUS] = 0x28, +}; + +static const struct alpha_pll_config cbfpll_config = { + .l = 72, + .config_ctl_val = 0x200d4828, + .config_ctl_hi_val = 0x006, + .test_ctl_val = 0x1c000000, + .test_ctl_hi_val = 0x00004000, + .pre_div_mask = BIT(12), + .post_div_mask = 0x3 << 8, + .post_div_val = 0x1 << 8, + .main_output_mask = BIT(0), + .early_output_mask = BIT(3), +}; + +static struct clk_alpha_pll cbf_pll = { + .offset = CBF_PLL_OFFSET, + .regs = cbf_pll_regs, + .flags = SUPPORTS_DYNAMIC_UPDATE | SUPPORTS_FSM_MODE, + .clkr.hw.init = &(struct clk_init_data){ + .name = "cbf_pll", + .parent_data = (const struct clk_parent_data[]) { + { .index = DT_XO, }, + }, + .num_parents = 1, + .ops = &clk_alpha_pll_hwfsm_ops, + }, +}; + +static struct clk_fixed_factor cbf_pll_postdiv = { + .mult = 1, + .div = 2, + .hw.init = &(struct clk_init_data){ + .name = "cbf_pll_postdiv", + .parent_data = &(const struct clk_parent_data){ + .hw = &cbf_pll.clkr.hw + }, + .num_parents = 1, + .ops = &clk_fixed_factor_ops, + .flags = CLK_SET_RATE_PARENT, + }, +}; + +static const struct clk_parent_data cbf_mux_parent_data[] = { + { .index = DT_XO }, + { .hw = &cbf_pll.clkr.hw }, + { .hw = &cbf_pll_postdiv.hw }, + { .index = DT_APCS_AUX }, +}; + +struct clk_cbf_8996_mux { + u32 reg; + struct notifier_block nb; + struct clk_regmap clkr; +}; + +static struct clk_cbf_8996_mux *to_clk_cbf_8996_mux(struct clk_regmap *clkr) +{ + return container_of(clkr, struct clk_cbf_8996_mux, clkr); +} + +static int cbf_clk_notifier_cb(struct notifier_block *nb, unsigned long event, + void *data); + +static u8 clk_cbf_8996_mux_get_parent(struct clk_hw *hw) +{ + struct clk_regmap *clkr = to_clk_regmap(hw); + struct clk_cbf_8996_mux *mux = to_clk_cbf_8996_mux(clkr); + u32 val; + + regmap_read(clkr->regmap, mux->reg, &val); + + return FIELD_GET(CBF_MUX_PARENT_MASK, val); +} + +static int clk_cbf_8996_mux_set_parent(struct clk_hw *hw, u8 index) +{ + struct clk_regmap *clkr = to_clk_regmap(hw); + struct clk_cbf_8996_mux *mux = to_clk_cbf_8996_mux(clkr); + u32 val; + + val = FIELD_PREP(CBF_MUX_PARENT_MASK, index); + + return regmap_update_bits(clkr->regmap, mux->reg, CBF_MUX_PARENT_MASK, val); +} + +static int clk_cbf_8996_mux_determine_rate(struct clk_hw *hw, + struct clk_rate_request *req) +{ + struct clk_hw *parent; + + if (req->rate < (DIV_THRESHOLD / 2)) + return -EINVAL; + + if (req->rate < DIV_THRESHOLD) + parent = clk_hw_get_parent_by_index(hw, CBF_DIV_INDEX); + else + parent = clk_hw_get_parent_by_index(hw, CBF_PLL_INDEX); + + if (!parent) + return -EINVAL; + + req->best_parent_rate = clk_hw_round_rate(parent, req->rate); + req->best_parent_hw = parent; + + return 0; +} + +static const struct clk_ops clk_cbf_8996_mux_ops = { + .set_parent = clk_cbf_8996_mux_set_parent, + .get_parent = clk_cbf_8996_mux_get_parent, + .determine_rate = clk_cbf_8996_mux_determine_rate, +}; + +static struct clk_cbf_8996_mux cbf_mux = { + .reg = CBF_MUX_OFFSET, + .nb.notifier_call = cbf_clk_notifier_cb, + .clkr.hw.init = &(struct clk_init_data) { + .name = "cbf_mux", + .parent_data = cbf_mux_parent_data, + .num_parents = ARRAY_SIZE(cbf_mux_parent_data), + .ops = &clk_cbf_8996_mux_ops, + /* CPU clock is critical and should never be gated */ + .flags = CLK_SET_RATE_PARENT | CLK_IS_CRITICAL, + }, +}; + +static int cbf_clk_notifier_cb(struct notifier_block *nb, unsigned long event, + void *data) +{ + struct clk_notifier_data *cnd = data; + int ret; + + switch (event) { + case PRE_RATE_CHANGE: + /* + * Avoid overvolting. clk_core_set_rate_nolock() walks from top + * to bottom, so it will change the rate of the PLL before + * chaging the parent of PMUX. This can result in pmux getting + * clocked twice the expected rate. + * + * Manually switch to PLL/2 here. + */ + if (cnd->old_rate > DIV_THRESHOLD && + cnd->new_rate < DIV_THRESHOLD) + clk_cbf_8996_mux_set_parent(&cbf_mux.clkr.hw, CBF_DIV_INDEX); + break; + case ABORT_RATE_CHANGE: + /* Revert manual change */ + if (cnd->new_rate < DIV_THRESHOLD && + cnd->old_rate > DIV_THRESHOLD) + clk_cbf_8996_mux_set_parent(&cbf_mux.clkr.hw, CBF_PLL_INDEX); + break; + default: + ret = 0; + break; + } + + return notifier_from_errno(ret); +}; + +static struct clk_hw *cbf_msm8996_hw_clks[] = { + &cbf_pll_postdiv.hw, +}; + +static struct clk_regmap *cbf_msm8996_clks[] = { + &cbf_pll.clkr, + &cbf_mux.clkr, +}; + +static const struct regmap_config cbf_msm8996_regmap_config = { + .reg_bits = 32, + .reg_stride = 4, + .val_bits = 32, + .max_register = 0x10000, + .fast_io = true, + .val_format_endian = REGMAP_ENDIAN_LITTLE, +}; + +static int qcom_msm8996_cbf_probe(struct platform_device *pdev) +{ + void __iomem *base; + struct regmap *regmap; + struct device *dev = &pdev->dev; + int i, ret; + + base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(base)) + return PTR_ERR(base); + + regmap = devm_regmap_init_mmio(dev, base, &cbf_msm8996_regmap_config); + if (IS_ERR(regmap)) + return PTR_ERR(regmap); + + /* Select GPLL0 for 300MHz for the CBF clock */ + regmap_write(regmap, CBF_MUX_OFFSET, 0x3); + + /* Ensure write goes through before PLLs are reconfigured */ + udelay(5); + + /* Set the auto clock sel always-on source to GPLL0/2 (300MHz) */ + regmap_update_bits(regmap, CBF_MUX_OFFSET, + CBF_MUX_AUTO_CLK_SEL_ALWAYS_ON_MASK, + CBF_MUX_AUTO_CLK_SEL_ALWAYS_ON_GPLL0_SEL); + + clk_alpha_pll_configure(&cbf_pll, regmap, &cbfpll_config); + + /* Wait for PLL(s) to lock */ + udelay(50); + + /* Enable auto clock selection for CBF */ + regmap_update_bits(regmap, CBF_MUX_OFFSET, + CBF_MUX_AUTO_CLK_SEL_BIT, + CBF_MUX_AUTO_CLK_SEL_BIT); + + /* Ensure write goes through before muxes are switched */ + udelay(5); + + /* Switch CBF to use the primary PLL */ + regmap_update_bits(regmap, CBF_MUX_OFFSET, + CBF_MUX_PARENT_MASK, 0x1); + + for (i = 0; i < ARRAY_SIZE(cbf_msm8996_hw_clks); i++) { + ret = devm_clk_hw_register(dev, cbf_msm8996_hw_clks[i]); + if (ret) + return ret; + } + + for (i = 0; i < ARRAY_SIZE(cbf_msm8996_clks); i++) { + ret = devm_clk_register_regmap(dev, cbf_msm8996_clks[i]); + if (ret) + return ret; + } + + ret = devm_clk_notifier_register(dev, cbf_mux.clkr.hw.clk, &cbf_mux.nb); + if (ret) + return ret; + + return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, &cbf_mux.clkr.hw); +} + +static const struct of_device_id qcom_msm8996_cbf_match_table[] = { + { .compatible = "qcom,msm8996-cbf" }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, qcom_msm8996_cbf_match_table); + +static struct platform_driver qcom_msm8996_cbf_driver = { + .probe = qcom_msm8996_cbf_probe, + .driver = { + .name = "qcom-msm8996-cbf", + .of_match_table = qcom_msm8996_cbf_match_table, + }, +}; + +/* Register early enough to fix the clock to be used for other cores */ +static int __init qcom_msm8996_cbf_init(void) +{ + return platform_driver_register(&qcom_msm8996_cbf_driver); +} +postcore_initcall(qcom_msm8996_cbf_init); + +static void __exit qcom_msm8996_cbf_exit(void) +{ + platform_driver_unregister(&qcom_msm8996_cbf_driver); +} +module_exit(qcom_msm8996_cbf_exit); + +MODULE_DESCRIPTION("QCOM MSM8996 CPU Bus Fabric Clock Driver"); +MODULE_LICENSE("GPL v2"); -- 2.30.2
