// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2018-2019 SiFive, Inc. * Wesley Terpstra * Paul Walmsley * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * The FU540 PRCI implements clock and reset control for the SiFive * FU540-C000 chip. This driver assumes that it has sole control * over all PRCI resources. * * This driver is based on the PRCI driver written by Wesley Terpstra: * https://github.com/riscv/riscv-linux/commit/999529edf517ed75b56659d456d221b2ee56bb60 * * References: * - SiFive FU540-C000 manual v1p0, Chapter 7 "Clocking and Reset" */ #include #include #include #include #include #include #include #include #include #include #include #include /* * EXPECTED_CLK_PARENT_COUNT: how many parent clocks this driver expects: * hfclk and rtcclk */ #define EXPECTED_CLK_PARENT_COUNT 2 /* * Register offsets and bitmasks */ /* COREPLLCFG0 */ #define PRCI_COREPLLCFG0_OFFSET 0x4 # define PRCI_COREPLLCFG0_DIVR_SHIFT 0 # define PRCI_COREPLLCFG0_DIVR_MASK (0x3f << PRCI_COREPLLCFG0_DIVR_SHIFT) # define PRCI_COREPLLCFG0_DIVF_SHIFT 6 # define PRCI_COREPLLCFG0_DIVF_MASK (0x1ff << PRCI_COREPLLCFG0_DIVF_SHIFT) # define PRCI_COREPLLCFG0_DIVQ_SHIFT 15 # define PRCI_COREPLLCFG0_DIVQ_MASK (0x7 << PRCI_COREPLLCFG0_DIVQ_SHIFT) # define PRCI_COREPLLCFG0_RANGE_SHIFT 18 # define PRCI_COREPLLCFG0_RANGE_MASK (0x7 << PRCI_COREPLLCFG0_RANGE_SHIFT) # define PRCI_COREPLLCFG0_BYPASS_SHIFT 24 # define PRCI_COREPLLCFG0_BYPASS_MASK (0x1 << PRCI_COREPLLCFG0_BYPASS_SHIFT) # define PRCI_COREPLLCFG0_FSE_SHIFT 25 # define PRCI_COREPLLCFG0_FSE_MASK (0x1 << PRCI_COREPLLCFG0_FSE_SHIFT) # define PRCI_COREPLLCFG0_LOCK_SHIFT 31 # define PRCI_COREPLLCFG0_LOCK_MASK (0x1 << PRCI_COREPLLCFG0_LOCK_SHIFT) /* DDRPLLCFG0 */ #define PRCI_DDRPLLCFG0_OFFSET 0xc # define PRCI_DDRPLLCFG0_DIVR_SHIFT 0 # define PRCI_DDRPLLCFG0_DIVR_MASK (0x3f << PRCI_DDRPLLCFG0_DIVR_SHIFT) # define PRCI_DDRPLLCFG0_DIVF_SHIFT 6 # define PRCI_DDRPLLCFG0_DIVF_MASK (0x1ff << PRCI_DDRPLLCFG0_DIVF_SHIFT) # define PRCI_DDRPLLCFG0_DIVQ_SHIFT 15 # define PRCI_DDRPLLCFG0_DIVQ_MASK (0x7 << PRCI_DDRPLLCFG0_DIVQ_SHIFT) # define PRCI_DDRPLLCFG0_RANGE_SHIFT 18 # define PRCI_DDRPLLCFG0_RANGE_MASK (0x7 << PRCI_DDRPLLCFG0_RANGE_SHIFT) # define PRCI_DDRPLLCFG0_BYPASS_SHIFT 24 # define PRCI_DDRPLLCFG0_BYPASS_MASK (0x1 << PRCI_DDRPLLCFG0_BYPASS_SHIFT) # define PRCI_DDRPLLCFG0_FSE_SHIFT 25 # define PRCI_DDRPLLCFG0_FSE_MASK (0x1 << PRCI_DDRPLLCFG0_FSE_SHIFT) # define PRCI_DDRPLLCFG0_LOCK_SHIFT 31 # define PRCI_DDRPLLCFG0_LOCK_MASK (0x1 << PRCI_DDRPLLCFG0_LOCK_SHIFT) /* DDRPLLCFG1 */ #define PRCI_DDRPLLCFG1_OFFSET 0x10 # define PRCI_DDRPLLCFG1_CKE_SHIFT 24 # define PRCI_DDRPLLCFG1_CKE_MASK (0x1 << PRCI_DDRPLLCFG1_CKE_SHIFT) /* GEMGXLPLLCFG0 */ #define PRCI_GEMGXLPLLCFG0_OFFSET 0x1c # define PRCI_GEMGXLPLLCFG0_DIVR_SHIFT 0 # define PRCI_GEMGXLPLLCFG0_DIVR_MASK (0x3f << PRCI_GEMGXLPLLCFG0_DIVR_SHIFT) # define PRCI_GEMGXLPLLCFG0_DIVF_SHIFT 6 # define PRCI_GEMGXLPLLCFG0_DIVF_MASK (0x1ff << PRCI_GEMGXLPLLCFG0_DIVF_SHIFT) # define PRCI_GEMGXLPLLCFG0_DIVQ_SHIFT 15 # define PRCI_GEMGXLPLLCFG0_DIVQ_MASK (0x7 << PRCI_GEMGXLPLLCFG0_DIVQ_SHIFT) # define PRCI_GEMGXLPLLCFG0_RANGE_SHIFT 18 # define PRCI_GEMGXLPLLCFG0_RANGE_MASK (0x7 << PRCI_GEMGXLPLLCFG0_RANGE_SHIFT) # define PRCI_GEMGXLPLLCFG0_BYPASS_SHIFT 24 # define PRCI_GEMGXLPLLCFG0_BYPASS_MASK (0x1 << PRCI_GEMGXLPLLCFG0_BYPASS_SHIFT) # define PRCI_GEMGXLPLLCFG0_FSE_SHIFT 25 # define PRCI_GEMGXLPLLCFG0_FSE_MASK (0x1 << PRCI_GEMGXLPLLCFG0_FSE_SHIFT) # define PRCI_GEMGXLPLLCFG0_LOCK_SHIFT 31 # define PRCI_GEMGXLPLLCFG0_LOCK_MASK (0x1 << PRCI_GEMGXLPLLCFG0_LOCK_SHIFT) /* GEMGXLPLLCFG1 */ #define PRCI_GEMGXLPLLCFG1_OFFSET 0x20 # define PRCI_GEMGXLPLLCFG1_CKE_SHIFT 24 # define PRCI_GEMGXLPLLCFG1_CKE_MASK (0x1 << PRCI_GEMGXLPLLCFG1_CKE_SHIFT) /* CORECLKSEL */ #define PRCI_CORECLKSEL_OFFSET 0x24 # define PRCI_CORECLKSEL_CORECLKSEL_SHIFT 0 # define PRCI_CORECLKSEL_CORECLKSEL_MASK (0x1 << PRCI_CORECLKSEL_CORECLKSEL_SHIFT) /* DEVICESRESETREG */ #define PRCI_DEVICESRESETREG_OFFSET 0x28 # define PRCI_DEVICESRESETREG_DDR_CTRL_RST_N_SHIFT 0 # define PRCI_DEVICESRESETREG_DDR_CTRL_RST_N_MASK (0x1 << PRCI_DEVICESRESETREG_DDR_CTRL_RST_N_SHIFT) # define PRCI_DEVICESRESETREG_DDR_AXI_RST_N_SHIFT 1 # define PRCI_DEVICESRESETREG_DDR_AXI_RST_N_MASK (0x1 << PRCI_DEVICESRESETREG_DDR_AXI_RST_N_SHIFT) # define PRCI_DEVICESRESETREG_DDR_AHB_RST_N_SHIFT 2 # define PRCI_DEVICESRESETREG_DDR_AHB_RST_N_MASK (0x1 << PRCI_DEVICESRESETREG_DDR_AHB_RST_N_SHIFT) # define PRCI_DEVICESRESETREG_DDR_PHY_RST_N_SHIFT 3 # define PRCI_DEVICESRESETREG_DDR_PHY_RST_N_MASK (0x1 << PRCI_DEVICESRESETREG_DDR_PHY_RST_N_SHIFT) # define PRCI_DEVICESRESETREG_GEMGXL_RST_N_SHIFT 5 # define PRCI_DEVICESRESETREG_GEMGXL_RST_N_MASK (0x1 << PRCI_DEVICESRESETREG_GEMGXL_RST_N_SHIFT) /* CLKMUXSTATUSREG */ #define PRCI_CLKMUXSTATUSREG_OFFSET 0x2c # define PRCI_CLKMUXSTATUSREG_TLCLKSEL_STATUS_SHIFT 1 # define PRCI_CLKMUXSTATUSREG_TLCLKSEL_STATUS_MASK (0x1 << PRCI_CLKMUXSTATUSREG_TLCLKSEL_STATUS_SHIFT) /* * Private structures */ /** * struct __prci_data - per-device-instance data * @va: base virtual address of the PRCI IP block * @hw_clks: encapsulates struct clk_hw records * * PRCI per-device instance data */ struct __prci_data { void __iomem *va; struct clk_hw_onecell_data hw_clks; }; /** * struct __prci_wrpll_data - WRPLL configuration and integration data * @c: WRPLL current configuration record * @enable_bypass: fn ptr to code to bypass the WRPLL (if applicable; else NULL) * @disable_bypass: fn ptr to code to not bypass the WRPLL (or NULL) * @cfg0_offs: WRPLL CFG0 register offset (in bytes) from the PRCI base address * * @enable_bypass and @disable_bypass are used for WRPLL instances * that contain a separate external glitchless clock mux downstream * from the PLL. The WRPLL internal bypass mux is not glitchless. */ struct __prci_wrpll_data { struct wrpll_cfg c; void (*enable_bypass)(struct __prci_data *pd); void (*disable_bypass)(struct __prci_data *pd); u8 cfg0_offs; }; /** * struct __prci_clock - describes a clock device managed by PRCI * @name: user-readable clock name string - should match the manual * @parent_name: parent name for this clock * @ops: struct clk_ops for the Linux clock framework to use for control * @hw: Linux-private clock data * @pwd: WRPLL-specific data, associated with this clock (if not NULL) * @pd: PRCI-specific data associated with this clock (if not NULL) * * PRCI clock data. Used by the PRCI driver to register PRCI-provided * clocks to the Linux clock infrastructure. */ struct __prci_clock { const char *name; const char *parent_name; const struct clk_ops *ops; struct clk_hw hw; struct __prci_wrpll_data *pwd; struct __prci_data *pd; }; #define clk_hw_to_prci_clock(pwd) container_of(pwd, struct __prci_clock, hw) /* * Private functions */ /** * __prci_readl() - read from a PRCI register * @pd: PRCI context * @offs: register offset to read from (in bytes, from PRCI base address) * * Read the register located at offset @offs from the base virtual * address of the PRCI register target described by @pd, and return * the value to the caller. * * Context: Any context. * * Return: the contents of the register described by @pd and @offs. */ static u32 __prci_readl(struct __prci_data *pd, u32 offs) { return readl_relaxed(pd->va + offs); } static void __prci_writel(u32 v, u32 offs, struct __prci_data *pd) { writel_relaxed(v, pd->va + offs); } /* WRPLL-related private functions */ /** * __prci_wrpll_unpack() - unpack WRPLL configuration registers into parameters * @c: ptr to a struct wrpll_cfg record to write config into * @r: value read from the PRCI PLL configuration register * * Given a value @r read from an FU540 PRCI PLL configuration register, * split it into fields and populate it into the WRPLL configuration record * pointed to by @c. * * The COREPLLCFG0 macros are used below, but the other *PLLCFG0 macros * have the same register layout. * * Context: Any context. */ static void __prci_wrpll_unpack(struct wrpll_cfg *c, u32 r) { u32 v; v = r & PRCI_COREPLLCFG0_DIVR_MASK; v >>= PRCI_COREPLLCFG0_DIVR_SHIFT; c->divr = v; v = r & PRCI_COREPLLCFG0_DIVF_MASK; v >>= PRCI_COREPLLCFG0_DIVF_SHIFT; c->divf = v; v = r & PRCI_COREPLLCFG0_DIVQ_MASK; v >>= PRCI_COREPLLCFG0_DIVQ_SHIFT; c->divq = v; v = r & PRCI_COREPLLCFG0_RANGE_MASK; v >>= PRCI_COREPLLCFG0_RANGE_SHIFT; c->range = v; c->flags &= (WRPLL_FLAGS_INT_FEEDBACK_MASK | WRPLL_FLAGS_EXT_FEEDBACK_MASK); /* external feedback mode not supported */ c->flags |= WRPLL_FLAGS_INT_FEEDBACK_MASK; } /** * __prci_wrpll_pack() - pack PLL configuration parameters into a register value * @c: pointer to a struct wrpll_cfg record containing the PLL's cfg * * Using a set of WRPLL configuration values pointed to by @c, * assemble a PRCI PLL configuration register value, and return it to * the caller. * * Context: Any context. Caller must ensure that the contents of the * record pointed to by @c do not change during the execution * of this function. * * Returns: a value suitable for writing into a PRCI PLL configuration * register */ static u32 __prci_wrpll_pack(const struct wrpll_cfg *c) { u32 r = 0; r |= c->divr << PRCI_COREPLLCFG0_DIVR_SHIFT; r |= c->divf << PRCI_COREPLLCFG0_DIVF_SHIFT; r |= c->divq << PRCI_COREPLLCFG0_DIVQ_SHIFT; r |= c->range << PRCI_COREPLLCFG0_RANGE_SHIFT; /* external feedback mode not supported */ r |= PRCI_COREPLLCFG0_FSE_MASK; return r; } /** * __prci_wrpll_read_cfg() - read the WRPLL configuration from the PRCI * @pd: PRCI context * @pwd: PRCI WRPLL metadata * * Read the current configuration of the PLL identified by @pwd from * the PRCI identified by @pd, and store it into the local configuration * cache in @pwd. * * Context: Any context. Caller must prevent the records pointed to by * @pd and @pwd from changing during execution. */ static void __prci_wrpll_read_cfg(struct __prci_data *pd, struct __prci_wrpll_data *pwd) { __prci_wrpll_unpack(&pwd->c, __prci_readl(pd, pwd->cfg0_offs)); } /** * __prci_wrpll_write_cfg() - write WRPLL configuration into the PRCI * @pd: PRCI context * @pwd: PRCI WRPLL metadata * @c: WRPLL configuration record to write * * Write the WRPLL configuration described by @c into the WRPLL * configuration register identified by @pwd in the PRCI instance * described by @c. Make a cached copy of the WRPLL's current * configuration so it can be used by other code. * * Context: Any context. Caller must prevent the records pointed to by * @pd and @pwd from changing during execution. */ static void __prci_wrpll_write_cfg(struct __prci_data *pd, struct __prci_wrpll_data *pwd, struct wrpll_cfg *c) { __prci_writel(__prci_wrpll_pack(c), pwd->cfg0_offs, pd); memcpy(&pwd->c, c, sizeof(*c)); } /* Core clock mux control */ /** * __prci_coreclksel_use_hfclk() - switch the CORECLK mux to output HFCLK * @pd: struct __prci_data * for the PRCI containing the CORECLK mux reg * * Switch the CORECLK mux to the HFCLK input source; return once complete. * * Context: Any context. Caller must prevent concurrent changes to the * PRCI_CORECLKSEL_OFFSET register. */ static void __prci_coreclksel_use_hfclk(struct __prci_data *pd) { u32 r; r = __prci_readl(pd, PRCI_CORECLKSEL_OFFSET); r |= PRCI_CORECLKSEL_CORECLKSEL_MASK; __prci_writel(r, PRCI_CORECLKSEL_OFFSET, pd); r = __prci_readl(pd, PRCI_CORECLKSEL_OFFSET); /* barrier */ } /** * __prci_coreclksel_use_corepll() - switch the CORECLK mux to output COREPLL * @pd: struct __prci_data * for the PRCI containing the CORECLK mux reg * * Switch the CORECLK mux to the PLL output clock; return once complete. * * Context: Any context. Caller must prevent concurrent changes to the * PRCI_CORECLKSEL_OFFSET register. */ static void __prci_coreclksel_use_corepll(struct __prci_data *pd) { u32 r; r = __prci_readl(pd, PRCI_CORECLKSEL_OFFSET); r &= ~PRCI_CORECLKSEL_CORECLKSEL_MASK; __prci_writel(r, PRCI_CORECLKSEL_OFFSET, pd); r = __prci_readl(pd, PRCI_CORECLKSEL_OFFSET); /* barrier */ } /* * Linux clock framework integration * * See the Linux clock framework documentation for more information on * these functions. */ static unsigned long sifive_fu540_prci_wrpll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { struct __prci_clock *pc = clk_hw_to_prci_clock(hw); struct __prci_wrpll_data *pwd = pc->pwd; return wrpll_calc_output_rate(&pwd->c, parent_rate); } static long sifive_fu540_prci_wrpll_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *parent_rate) { struct __prci_clock *pc = clk_hw_to_prci_clock(hw); struct __prci_wrpll_data *pwd = pc->pwd; struct wrpll_cfg c; memcpy(&c, &pwd->c, sizeof(c)); wrpll_configure_for_rate(&c, rate, *parent_rate); return wrpll_calc_output_rate(&c, *parent_rate); } static int sifive_fu540_prci_wrpll_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long parent_rate) { struct __prci_clock *pc = clk_hw_to_prci_clock(hw); struct __prci_wrpll_data *pwd = pc->pwd; struct __prci_data *pd = pc->pd; int r; r = wrpll_configure_for_rate(&pwd->c, rate, parent_rate); if (r) return r; if (pwd->enable_bypass) pwd->enable_bypass(pd); __prci_wrpll_write_cfg(pd, pwd, &pwd->c); udelay(wrpll_calc_max_lock_us(&pwd->c)); if (pwd->disable_bypass) pwd->disable_bypass(pd); return 0; } static const struct clk_ops sifive_fu540_prci_wrpll_clk_ops = { .set_rate = sifive_fu540_prci_wrpll_set_rate, .round_rate = sifive_fu540_prci_wrpll_round_rate, .recalc_rate = sifive_fu540_prci_wrpll_recalc_rate, }; static const struct clk_ops sifive_fu540_prci_wrpll_ro_clk_ops = { .recalc_rate = sifive_fu540_prci_wrpll_recalc_rate, }; /* TLCLKSEL clock integration */ static unsigned long sifive_fu540_prci_tlclksel_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { struct __prci_clock *pc = clk_hw_to_prci_clock(hw); struct __prci_data *pd = pc->pd; u32 v; u8 div; v = __prci_readl(pd, PRCI_CLKMUXSTATUSREG_OFFSET); v &= PRCI_CLKMUXSTATUSREG_TLCLKSEL_STATUS_MASK; div = v ? 1 : 2; return div_u64(parent_rate, div); } static const struct clk_ops sifive_fu540_prci_tlclksel_clk_ops = { .recalc_rate = sifive_fu540_prci_tlclksel_recalc_rate, }; /* * PRCI integration data for each WRPLL instance */ static struct __prci_wrpll_data __prci_corepll_data = { .cfg0_offs = PRCI_COREPLLCFG0_OFFSET, .enable_bypass = __prci_coreclksel_use_hfclk, .disable_bypass = __prci_coreclksel_use_corepll, }; static struct __prci_wrpll_data __prci_ddrpll_data = { .cfg0_offs = PRCI_DDRPLLCFG0_OFFSET, }; static struct __prci_wrpll_data __prci_gemgxlpll_data = { .cfg0_offs = PRCI_GEMGXLPLLCFG0_OFFSET, }; /* * List of clock controls provided by the PRCI */ static struct __prci_clock __prci_init_clocks[] = { [PRCI_CLK_COREPLL] = { .name = "corepll", .parent_name = "hfclk", .ops = &sifive_fu540_prci_wrpll_clk_ops, .pwd = &__prci_corepll_data, }, [PRCI_CLK_DDRPLL] = { .name = "ddrpll", .parent_name = "hfclk", .ops = &sifive_fu540_prci_wrpll_ro_clk_ops, .pwd = &__prci_ddrpll_data, }, [PRCI_CLK_GEMGXLPLL] = { .name = "gemgxlpll", .parent_name = "hfclk", .ops = &sifive_fu540_prci_wrpll_clk_ops, .pwd = &__prci_gemgxlpll_data, }, [PRCI_CLK_TLCLK] = { .name = "tlclk", .parent_name = "corepll", .ops = &sifive_fu540_prci_tlclksel_clk_ops, }, }; /** * __prci_register_clocks() - register clock controls in the PRCI with Linux * @dev: Linux struct device * * * Register the list of clock controls described in __prci_init_plls[] with * the Linux clock framework. * * Return: 0 upon success or a negative error code upon failure. */ static int __prci_register_clocks(struct device *dev, struct __prci_data *pd) { struct clk_init_data init = { }; struct __prci_clock *pic; int parent_count, i, r; parent_count = of_clk_get_parent_count(dev->of_node); if (parent_count != EXPECTED_CLK_PARENT_COUNT) { dev_err(dev, "expected only two parent clocks, found %d\n", parent_count); return -EINVAL; } /* Register PLLs */ for (i = 0; i < ARRAY_SIZE(__prci_init_clocks); ++i) { pic = &__prci_init_clocks[i]; init.name = pic->name; init.parent_names = &pic->parent_name; init.num_parents = 1; init.ops = pic->ops; pic->hw.init = &init; pic->pd = pd; if (pic->pwd) __prci_wrpll_read_cfg(pd, pic->pwd); r = devm_clk_hw_register(dev, &pic->hw); if (r) { dev_warn(dev, "Failed to register clock %s: %d\n", init.name, r); return r; } r = clk_hw_register_clkdev(&pic->hw, pic->name, dev_name(dev)); if (r) { dev_warn(dev, "Failed to register clkdev for %s: %d\n", init.name, r); return r; } pd->hw_clks.hws[i] = &pic->hw; } pd->hw_clks.num = i; r = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, &pd->hw_clks); if (r) { dev_err(dev, "could not add hw_provider: %d\n", r); return r; } return 0; } /* * Linux device model integration * * See the Linux device model documentation for more information about * these functions. */ static int sifive_fu540_prci_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct resource *res; struct __prci_data *pd; int r; pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL); if (!pd) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); pd->va = devm_ioremap_resource(dev, res); if (IS_ERR(pd->va)) return PTR_ERR(pd->va); r = __prci_register_clocks(dev, pd); if (r) { dev_err(dev, "could not register clocks: %d\n", r); return r; } dev_dbg(dev, "SiFive FU540 PRCI probed\n"); return 0; } static const struct of_device_id sifive_fu540_prci_of_match[] = { { .compatible = "sifive,fu540-c000-prci", }, {} }; MODULE_DEVICE_TABLE(of, sifive_fu540_prci_of_match); static struct platform_driver sifive_fu540_prci_driver = { .driver = { .name = "sifive-fu540-prci", .of_match_table = sifive_fu540_prci_of_match, }, .probe = sifive_fu540_prci_probe, }; static int __init sifive_fu540_prci_init(void) { return platform_driver_register(&sifive_fu540_prci_driver); } core_initcall(sifive_fu540_prci_init);