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// 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 <dt-bindings/clock/sifive-fu540-prci.h>
#include <linux/clkdev.h>
#include <linux/clk-provider.h>
#include <linux/clk/analogbits-wrpll-cln28hpc.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_clk.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
/*
* 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 Lin
|