From 64aa7008e957a0a60f1ca3227d85ad1e507252cd Mon Sep 17 00:00:00 2001 From: Martin Blumenstingl Date: Sun, 17 Nov 2019 15:07:31 +0100 Subject: [PATCH] clk: meson: add a driver for the Meson8/8b/8m2 DDR clock controller The Meson8/Meson8b/Meson8m2 SoCs embed a DDR clock controller in the MMCBUS registers. There is no public documentation, but the u-boot GPL sources from the Amlogic BSP show that the DDR clock controller is identical on all three SoCs: #define CFG_DDR_CLK 792 #define CFG_PLL_M (((CFG_DDR_CLK/12)*12)/24) #define CFG_PLL_N 1 #define CFG_PLL_OD 1 // from set_ddr_clock: t_ddr_pll_cntl= (CFG_PLL_OD << 16)|(CFG_PLL_N<<9)|(CFG_PLL_M<<0) writel(timing_reg->t_ddr_pll_cntl|(1<<29),AM_DDR_PLL_CNTL); writel(readl(AM_DDR_PLL_CNTL) & (~(1<<29)),AM_DDR_PLL_CNTL); // from hx_ddr_power_down_enter: shut down DDR PLL writel(readl(AM_DDR_PLL_CNTL)|(1<<30),AM_DDR_PLL_CNTL); do { ... } while((readl(AM_DDR_PLL_CNTL)&(1<<31))==0) This translates to: - AM_DDR_PLL_CNTL[29] is the reset bit - AM_DDR_PLL_CNTL[30] is the enable bit - AM_DDR_PLL_CNTL[31] is the lock bit - AM_DDR_PLL_CNTL[8:0] is the m value (assuming the width is 9 bits based on the start of the n value) - AM_DDR_PLL_CNTL[13:9] is the n value (assuming the width is 5 bits based on the start of the od) - AM_DDR_PLL_CNTL[17:16] is the od (assuming the width is 2 bits based on other PLLs on this SoC) Add a driver for this PLL setup because it's used as one of the inputs of the audio clocks. There may be more clocks inside that clock controller - those can be added in subsequent patches. Signed-off-by: Martin Blumenstingl Signed-off-by: Jerome Brunet --- drivers/clk/meson/Makefile | 2 +- drivers/clk/meson/meson8-ddr.c | 149 +++++++++++++++++++++++++++++++++ 2 files changed, 150 insertions(+), 1 deletion(-) create mode 100644 drivers/clk/meson/meson8-ddr.c diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile index 3939f218587a..6eca2a406ee3 100644 --- a/drivers/clk/meson/Makefile +++ b/drivers/clk/meson/Makefile @@ -18,4 +18,4 @@ obj-$(CONFIG_COMMON_CLK_AXG) += axg.o axg-aoclk.o obj-$(CONFIG_COMMON_CLK_AXG_AUDIO) += axg-audio.o obj-$(CONFIG_COMMON_CLK_GXBB) += gxbb.o gxbb-aoclk.o obj-$(CONFIG_COMMON_CLK_G12A) += g12a.o g12a-aoclk.o -obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o +obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o meson8-ddr.o diff --git a/drivers/clk/meson/meson8-ddr.c b/drivers/clk/meson/meson8-ddr.c new file mode 100644 index 000000000000..4b73ea244b63 --- /dev/null +++ b/drivers/clk/meson/meson8-ddr.c @@ -0,0 +1,149 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Amlogic Meson8 DDR clock controller + * + * Copyright (C) 2019 Martin Blumenstingl + */ + +#include + +#include +#include + +#include "clk-regmap.h" +#include "clk-pll.h" + +#define AM_DDR_PLL_CNTL 0x00 +#define AM_DDR_PLL_CNTL1 0x04 +#define AM_DDR_PLL_CNTL2 0x08 +#define AM_DDR_PLL_CNTL3 0x0c +#define AM_DDR_PLL_CNTL4 0x10 +#define AM_DDR_PLL_STS 0x14 +#define DDR_CLK_CNTL 0x18 +#define DDR_CLK_STS 0x1c + +static struct clk_regmap meson8_ddr_pll_dco = { + .data = &(struct meson_clk_pll_data){ + .en = { + .reg_off = AM_DDR_PLL_CNTL, + .shift = 30, + .width = 1, + }, + .m = { + .reg_off = AM_DDR_PLL_CNTL, + .shift = 0, + .width = 9, + }, + .n = { + .reg_off = AM_DDR_PLL_CNTL, + .shift = 9, + .width = 5, + }, + .l = { + .reg_off = AM_DDR_PLL_CNTL, + .shift = 31, + .width = 1, + }, + .rst = { + .reg_off = AM_DDR_PLL_CNTL, + .shift = 29, + .width = 1, + }, + }, + .hw.init = &(struct clk_init_data){ + .name = "ddr_pll_dco", + .ops = &meson_clk_pll_ro_ops, + .parent_data = &(const struct clk_parent_data) { + .fw_name = "xtal", + }, + .num_parents = 1, + }, +}; + +static struct clk_regmap meson8_ddr_pll = { + .data = &(struct clk_regmap_div_data){ + .offset = AM_DDR_PLL_CNTL, + .shift = 16, + .width = 2, + .flags = CLK_DIVIDER_POWER_OF_TWO, + }, + .hw.init = &(struct clk_init_data){ + .name = "ddr_pll", + .ops = &clk_regmap_divider_ro_ops, + .parent_hws = (const struct clk_hw *[]) { + &meson8_ddr_pll_dco.hw + }, + .num_parents = 1, + }, +}; + +static struct clk_hw_onecell_data meson8_ddr_clk_hw_onecell_data = { + .hws = { + [DDR_CLKID_DDR_PLL_DCO] = &meson8_ddr_pll_dco.hw, + [DDR_CLKID_DDR_PLL] = &meson8_ddr_pll.hw, + }, + .num = 2, +}; + +static struct clk_regmap *const meson8_ddr_clk_regmaps[] = { + &meson8_ddr_pll_dco, + &meson8_ddr_pll, +}; + +static const struct regmap_config meson8_ddr_clkc_regmap_config = { + .reg_bits = 8, + .val_bits = 32, + .reg_stride = 4, + .max_register = DDR_CLK_STS, +}; + +static int meson8_ddr_clkc_probe(struct platform_device *pdev) +{ + struct regmap *regmap; + void __iomem *base; + struct clk_hw *hw; + int ret, i; + + base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(base)) + return PTR_ERR(base); + + regmap = devm_regmap_init_mmio(&pdev->dev, base, + &meson8_ddr_clkc_regmap_config); + if (IS_ERR(regmap)) + return PTR_ERR(regmap); + + /* Populate regmap */ + for (i = 0; i < ARRAY_SIZE(meson8_ddr_clk_regmaps); i++) + meson8_ddr_clk_regmaps[i]->map = regmap; + + /* Register all clks */ + for (i = 0; i < meson8_ddr_clk_hw_onecell_data.num; i++) { + hw = meson8_ddr_clk_hw_onecell_data.hws[i]; + + ret = devm_clk_hw_register(&pdev->dev, hw); + if (ret) { + dev_err(&pdev->dev, "Clock registration failed\n"); + return ret; + } + } + + return devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_onecell_get, + &meson8_ddr_clk_hw_onecell_data); +} + +static const struct of_device_id meson8_ddr_clkc_match_table[] = { + { .compatible = "amlogic,meson8-ddr-clkc" }, + { .compatible = "amlogic,meson8b-ddr-clkc" }, + { /* sentinel */ } +}; + +static struct platform_driver meson8_ddr_clkc_driver = { + .probe = meson8_ddr_clkc_probe, + .driver = { + .name = "meson8-ddr-clkc", + .of_match_table = meson8_ddr_clkc_match_table, + }, +}; + +builtin_platform_driver(meson8_ddr_clkc_driver);