From 32cfdd51630506393ca078aa36fa70248d549109 Mon Sep 17 00:00:00 2001 From: Conor Dooley Date: Tue, 25 Oct 2022 08:58:46 +0100 Subject: clk: microchip: mpfs: fix reference clock handling The original devicetrees for PolarFire SoC messed up & defined the msspll's output as a fixed-frequency, 600 MHz clock & used that as the input for the clock controller node. The msspll is not a fixed frequency clock and later devicetrees handled this properly. Check the devicetree & if it is one of the fixed ones, register the msspll. Otherwise, skip registering it & pass the reference clock directly to the cfg clock registration function so that existing devicetrees are not broken by this change. As the MSS PLL is not a "cfg" or a "periph" clock, add a new driver for it, based on the one in Linux. Fixes: 2f27c9219e ("clk: Add Microchip PolarFire SoC clock driver") Signed-off-by: Conor Dooley Reviewed-by: Leo Yu-Chi Liang Reviewed-by: Padmarao Begari Tested-by: Padmarao Begari --- drivers/clk/microchip/mpfs_clk.c | 23 +++++- drivers/clk/microchip/mpfs_clk.h | 8 +++ drivers/clk/microchip/mpfs_clk_msspll.c | 119 ++++++++++++++++++++++++++++++++ 3 files changed, 149 insertions(+), 1 deletion(-) create mode 100644 drivers/clk/microchip/mpfs_clk_msspll.c diff --git a/drivers/clk/microchip/mpfs_clk.c b/drivers/clk/microchip/mpfs_clk.c index 7ba1218b56..f16f716f00 100644 --- a/drivers/clk/microchip/mpfs_clk.c +++ b/drivers/clk/microchip/mpfs_clk.c @@ -20,10 +20,12 @@ static int mpfs_clk_probe(struct udevice *dev) { struct clk *parent_clk = dev_get_priv(dev); struct clk clk_ahb = { .id = CLK_AHB }; + struct clk clk_msspll = { .id = CLK_MSSPLL }; void __iomem *base; + void __iomem *msspll_base; int ret; - base = dev_read_addr_ptr(dev); + base = dev_read_addr_index_ptr(dev, 0); if (!base) return -EINVAL; @@ -31,6 +33,25 @@ static int mpfs_clk_probe(struct udevice *dev) if (ret) return ret; + /* + * The original devicetrees for mpfs messed up & defined the msspll's + * output as a fixed-frequency, 600 MHz clock & used that as the input + * for the clock controller node. The msspll is however not a fixed + * frequency clock and later devicetrees handled this properly. Check + * the devicetree & if it is one of the fixed ones, register the msspll. + * Otherwise, skip registering it & pass the reference clock directly + * to the cfg clock registration function. + */ + msspll_base = dev_read_addr_index_ptr(dev, 1); + if (msspll_base) { + ret = mpfs_clk_register_msspll(msspll_base, parent_clk); + if (ret) + return ret; + + clk_request(dev, &clk_msspll); + parent_clk = &clk_msspll; + } + ret = mpfs_clk_register_cfgs(base, parent_clk); if (ret) return ret; diff --git a/drivers/clk/microchip/mpfs_clk.h b/drivers/clk/microchip/mpfs_clk.h index 35cfeac92e..cb7d303e67 100644 --- a/drivers/clk/microchip/mpfs_clk.h +++ b/drivers/clk/microchip/mpfs_clk.h @@ -15,6 +15,14 @@ * Return: zero on success, or a negative error code. */ int mpfs_clk_register_cfgs(void __iomem *base, struct clk *parent); +/** + * mpfs_clk_register_msspll() - register the mss pll + * + * @base: base address of the mpfs system register. + * @parent: a pointer to parent clock. + * Return: zero on success, or a negative error code. + */ +int mpfs_clk_register_msspll(void __iomem *base, struct clk *parent); /** * mpfs_clk_register_periphs() - register peripheral clocks * diff --git a/drivers/clk/microchip/mpfs_clk_msspll.c b/drivers/clk/microchip/mpfs_clk_msspll.c new file mode 100644 index 0000000000..f37c0d8604 --- /dev/null +++ b/drivers/clk/microchip/mpfs_clk_msspll.c @@ -0,0 +1,119 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2022 Microchip Technology Inc. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "mpfs_clk.h" + +#define MPFS_MSSPLL_CLOCK "mpfs_msspll_clock" + +/* address offset of control registers */ +#define REG_MSSPLL_REF_CR 0x08u +#define REG_MSSPLL_POSTDIV_CR 0x10u +#define REG_MSSPLL_SSCG_2_CR 0x2Cu + +#define MSSPLL_FBDIV_SHIFT 0x00u +#define MSSPLL_FBDIV_WIDTH 0x0Cu +#define MSSPLL_REFDIV_SHIFT 0x08u +#define MSSPLL_REFDIV_WIDTH 0x06u +#define MSSPLL_POSTDIV_SHIFT 0x08u +#define MSSPLL_POSTDIV_WIDTH 0x07u +#define MSSPLL_FIXED_DIV 4u + +/** + * struct mpfs_msspll_hw_clock + * @id: index of the msspll clock + * @name: the msspll clocks name + * @reg_offset: offset to the core complex's output of the msspll + * @shift: shift to the divider bit field of a msspll clock output + * @width: width of the divider bit field of the msspll clock output + * @flags: common clock framework flags + * @prate: the reference clock rate + * @hw: clock instance + */ +struct mpfs_msspll_hw_clock { + void __iomem *base; + unsigned int id; + const char *name; + u32 reg_offset; + u32 shift; + u32 width; + u32 flags; + u32 prate; + struct clk hw; +}; + +#define to_mpfs_msspll_clk(_hw) container_of(_hw, struct mpfs_msspll_hw_clock, hw) + +static unsigned long mpfs_clk_msspll_recalc_rate(struct clk *hw) +{ + struct mpfs_msspll_hw_clock *msspll_hw = to_mpfs_msspll_clk(hw); + void __iomem *mult_addr = msspll_hw->base + msspll_hw->reg_offset; + void __iomem *ref_div_addr = msspll_hw->base + REG_MSSPLL_REF_CR; + void __iomem *postdiv_addr = msspll_hw->base + REG_MSSPLL_POSTDIV_CR; + u32 mult, ref_div, postdiv; + unsigned long temp; + + mult = readl(mult_addr) >> MSSPLL_FBDIV_SHIFT; + mult &= clk_div_mask(MSSPLL_FBDIV_WIDTH); + ref_div = readl(ref_div_addr) >> MSSPLL_REFDIV_SHIFT; + ref_div &= clk_div_mask(MSSPLL_REFDIV_WIDTH); + postdiv = readl(postdiv_addr) >> MSSPLL_POSTDIV_SHIFT; + postdiv &= clk_div_mask(MSSPLL_POSTDIV_WIDTH); + + temp = msspll_hw->prate / (ref_div * MSSPLL_FIXED_DIV * postdiv); + return temp * mult; +} + +#define CLK_PLL(_id, _name, _shift, _width, _reg_offset, _flags) { \ + .id = _id, \ + .name = _name, \ + .shift = _shift, \ + .width = _width, \ + .reg_offset = _reg_offset, \ + .flags = _flags, \ +} + +static struct mpfs_msspll_hw_clock mpfs_msspll_clks[] = { + CLK_PLL(CLK_MSSPLL, "clk_msspll", MSSPLL_FBDIV_SHIFT, + MSSPLL_FBDIV_WIDTH, REG_MSSPLL_SSCG_2_CR, 0), +}; + +int mpfs_clk_register_msspll(void __iomem *base, struct clk *parent) +{ + int id, ret; + const char *name; + struct clk *hw; + + hw = &mpfs_msspll_clks[0].hw; + mpfs_msspll_clks[0].base = base; + mpfs_msspll_clks[0].prate = clk_get_rate(parent); + name = mpfs_msspll_clks[0].name; + ret = clk_register(hw, MPFS_MSSPLL_CLOCK, name, parent->dev->name); + if (ret) + ERR_PTR(ret); + id = mpfs_msspll_clks[0].id; + clk_dm(id, hw); + + return 0; +} + +const struct clk_ops mpfs_msspll_clk_ops = { + .get_rate = mpfs_clk_msspll_recalc_rate, +}; + +U_BOOT_DRIVER(mpfs_msspll_clock) = { + .name = MPFS_MSSPLL_CLOCK, + .id = UCLASS_CLK, + .ops = &mpfs_msspll_clk_ops, +}; + -- cgit v1.2.3