Re: [PATCH v4 1/5] clk: Add clock driver for ASPEED BMC SoCs

From: Andrew Jeffery
Date: Thu Oct 05 2017 - 02:36:47 EST


On Tue, 2017-10-03 at 17:25 +1030, Joel Stanley wrote:
> This adds the stub of a driver for the ASPEED SoCs. The clocks are
> defined and the static registration is set up.
>Â
> Signed-off-by: Joel Stanley <joel@xxxxxxxxx>

With respect to use of the Aspeed hardware,

Reviewed-by: Andrew Jeffery <andrew@xxxxxxxx>

> ---
> v3:
> Â- use named initlisers for aspeed_gates table
> Â- fix clocks typo
> Â- Move ASPEED_NUM_CLKS to the bottom of the list
> Â- Put gates at the start of the list, so we can use them to initalise
> ÂÂÂthe aspeed_gates table
> Â- Add ASPEED_CLK_SELECTION_2
> Â- Set parent of network MAC gates
> ---
> Âdrivers/clk/KconfigÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ|ÂÂ12 +++
> Âdrivers/clk/MakefileÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ|ÂÂÂ1 +
> Âdrivers/clk/clk-aspeed.cÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ| 148 +++++++++++++++++++++++++++++++
> Âinclude/dt-bindings/clock/aspeed-clock.h |ÂÂ42 +++++++++
> Â4 files changed, 203 insertions(+)
> Âcreate mode 100644 drivers/clk/clk-aspeed.c
> Âcreate mode 100644 include/dt-bindings/clock/aspeed-clock.h
>Â
> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> index 1c4e1aa6767e..9abe063ef8d2 100644
> --- a/drivers/clk/Kconfig
> +++ b/drivers/clk/Kconfig
> @@ -142,6 +142,18 @@ config COMMON_CLK_GEMINI
> Â ÂÂThis driver supports the SoC clocks on the Cortina Systems Gemini
> Â ÂÂplatform, also known as SL3516 or CS3516.
> Â
> +config COMMON_CLK_ASPEED
> + bool "Clock driver for Aspeed BMC SoCs"
> + depends on ARCH_ASPEED || COMPILE_TEST
> + default ARCH_ASPEED
> + select MFD_SYSCON
> + select RESET_CONTROLLER
> + ---help---
> + ÂÂThis driver supports the SoC clocks on the Aspeed BMC platforms.
> +
> + ÂÂThe G4 and G5 series, including the ast2400 and ast2500, are supported
> + ÂÂby this driver.
> +
> Âconfig COMMON_CLK_S2MPS11
> Â tristate "Clock driver for S2MPS1X/S5M8767 MFD"
> Â depends on MFD_SEC_CORE || COMPILE_TEST
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index c99f363826f0..575c68919d9b 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -26,6 +26,7 @@ obj-$(CONFIG_ARCH_CLPS711X) += clk-clps711x.o
> Âobj-$(CONFIG_COMMON_CLK_CS2000_CP) += clk-cs2000-cp.o
> Âobj-$(CONFIG_ARCH_EFM32) += clk-efm32gg.o
> Âobj-$(CONFIG_COMMON_CLK_GEMINI) += clk-gemini.o
> +obj-$(CONFIG_COMMON_CLK_ASPEED) += clk-aspeed.o
> Âobj-$(CONFIG_ARCH_HIGHBANK) += clk-highbank.o
> Âobj-$(CONFIG_CLK_HSDK) += clk-hsdk-pll.o
> Âobj-$(CONFIG_COMMON_CLK_MAX77686) += clk-max77686.o
> diff --git a/drivers/clk/clk-aspeed.c b/drivers/clk/clk-aspeed.c
> new file mode 100644
> index 000000000000..a45eb351bb05
> --- /dev/null
> +++ b/drivers/clk/clk-aspeed.c
> @@ -0,0 +1,148 @@
> +/*
> + * Copyright 2017 IBM Corporation
> + *
> + * Joel Stanley <joel@xxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version
> + * 2 of the License, or (at your option) any later version.
> + */
> +
> +#define pr_fmt(fmt) "clk-aspeed: " fmt
> +
> +#include <linux/clk-provider.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/of_address.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +#include <linux/spinlock.h>
> +
> +#include <dt-bindings/clock/aspeed-clock.h>
> +
> +#define ASPEED_STRAP 0x70
> +
> +/* Keeps track of all clocks */
> +static struct clk_hw_onecell_data *aspeed_clk_data;
> +
> +static void __iomem *scu_base;
> +
> +/**
> + * struct aspeed_gate_data - Aspeed gated clocks
> + * @clock_idx: bit used to gate this clock in the clock register
> + * @reset_idx: bit used to reset this IP in the reset register. -1 if no
> + *ÂÂÂÂÂÂÂÂÂÂÂÂÂreset is required when enabling the clock
> + * @name: the clock name
> + * @parent_name: the name of the parent clock
> + * @flags: standard clock framework flags
> + */
> +struct aspeed_gate_data {
> + u8 clock_idx;
> + s8 reset_idx;
> + const char *name;
> + const char *parent_name;
> + unsigned long flags;
> +};
> +
> +/**
> + * struct aspeed_clk_gate - Aspeed specific clk_gate structure
> + * @hw: handle between common and hardware-specific interfaces
> + * @reg: register controlling gate
> + * @clock_idx: bit used to gate this clock in the clock register
> + * @reset_idx: bit used to reset this IP in the reset register. -1 if no
> + * reset is required when enabling the clock
> + * @flags: hardware-specific flags
> + * @lock: register lock
> + *
> + * Some of the clocks in the Aspeed SoC must be put in reset before enabling.
> + * This modified version of clk_gate allows an optional reset bit to be
> + * specified.
> + */
> +struct aspeed_clk_gate {
> + struct clk_hw hw;
> + struct regmap *map;
> + u8 clock_idx;
> + s8 reset_idx;
> + u8 flags;
> + spinlock_t *lock;
> +};
> +
> +#define to_aspeed_clk_gate(_hw) container_of(_hw, struct aspeed_clk_gate, hw)
> +
> +/* TODO: ask Aspeed about the actual parent data */
> +static const struct aspeed_gate_data aspeed_gates[] __initconst = {
> + /* Âclk rstÂÂÂname parent flags */
> + [ASPEED_CLK_GATE_ECLK] = {ÂÂ0, -1, "eclk-gate", "eclk", 0 }, /* Video Engine */
> + [ASPEED_CLK_GATE_GCLK] = {ÂÂ1,ÂÂ7, "gclk-gate", NULL, 0 }, /* 2D engine */
> + [ASPEED_CLK_GATE_MCLK] = {ÂÂ2, -1, "mclk-gate", "mpll", CLK_IS_CRITICAL }, /* SDRAM */
> + [ASPEED_CLK_GATE_VCLK] = {ÂÂ3,ÂÂ6, "vclk-gate", NULL, 0 }, /* Video Capture */
> + [ASPEED_CLK_GATE_BCLK] = {ÂÂ4, 10, "bclk-gate", "bclk", 0 }, /* PCIe/PCI */
> + [ASPEED_CLK_GATE_DCLK] = {ÂÂ5, -1, "dclk-gate", NULL, 0 }, /* DAC */
> + [ASPEED_CLK_GATE_REFCLK] = {ÂÂ6, -1, "refclk-gate", "clkin", CLK_IS_CRITICAL },
> + [ASPEED_CLK_GATE_USBPORT2CLK] = {ÂÂ7,ÂÂ3, "usb-port2-gate", NULL, 0 }, /* USB2.0 Host port 2 */
> + [ASPEED_CLK_GATE_LCLK] = {ÂÂ8,ÂÂ5, "lclk-gate", NULL, 0 }, /* LPC */
> + [ASPEED_CLK_GATE_USBUHCICLK] = {ÂÂ9, 15, "usb-uhci-gate", NULL, 0 }, /* USB1.1 (requires port 2 enabled) */
> + [ASPEED_CLK_GATE_D1CLK] = { 10, 13, "d1clk-gate", NULL, 0 }, /* GFX CRT */
> + [ASPEED_CLK_GATE_YCLK] = { 13,ÂÂ4, "yclk-gate", NULL, 0 }, /* HAC */
> + [ASPEED_CLK_GATE_USBPORT1CLK] = { 14, 14, "usb-port1-gate", NULL, 0 }, /* USB2 hub/USB2 host port 1/USB1.1 dev */
> + [ASPEED_CLK_GATE_UART1CLK] = { 15, -1, "uart1clk-gate", "uart", 0 }, /* UART1 */
> + [ASPEED_CLK_GATE_UART2CLK] = { 16, -1, "uart2clk-gate", "uart", 0 }, /* UART2 */
> + [ASPEED_CLK_GATE_UART5CLK] = { 17, -1, "uart5clk-gate", "uart", 0 }, /* UART5 */
> + [ASPEED_CLK_GATE_ESPICLK] = { 19, -1, "espiclk-gate", NULL, 0 }, /* eSPI */
> + [ASPEED_CLK_GATE_MAC1CLK] = { 20, 11, "mac1clk-gate", "mac", 0 }, /* MAC1 */
> + [ASPEED_CLK_GATE_MAC2CLK] = { 21, 12, "mac2clk-gate", "mac", 0 }, /* MAC2 */
> + [ASPEED_CLK_GATE_RSACLK] = { 24, -1, "rsaclk-gate", NULL, 0 }, /* RSA */
> + [ASPEED_CLK_GATE_UART3CLK] = { 25, -1, "uart3clk-gate", "uart", 0 }, /* UART3 */
> + [ASPEED_CLK_GATE_UART4CLK] = { 26, -1, "uart4clk-gate", "uart", 0 }, /* UART4 */
> + [ASPEED_CLK_GATE_SDCLKCLK] = { 27, 16, "sdclk-gate", NULL, 0 }, /* SDIO/SD */
> + [ASPEED_CLK_GATE_LHCCLK] = { 28, -1, "lhclk-gate", "lhclk", 0 }, /* LPC master/LPC+ */
> +};
> +
> +static void __init aspeed_cc_init(struct device_node *np)
> +{
> + struct regmap *map;
> + u32 val;
> + int ret;
> + int i;
> +
> + scu_base = of_iomap(np, 0);
> + if (IS_ERR(scu_base))
> + return;
> +
> + aspeed_clk_data = kzalloc(sizeof(*aspeed_clk_data) +
> + sizeof(*aspeed_clk_data->hws) * ASPEED_NUM_CLKS,
> + GFP_KERNEL);
> + if (!aspeed_clk_data)
> + return;
> +
> + /*
> + Â* This way all clocks fetched before the platform device probes,
> + Â* except those we assign here for early use, will be deferred.
> + Â*/
> + for (i = 0; i < ASPEED_NUM_CLKS; i++)
> + aspeed_clk_data->hws[i] = ERR_PTR(-EPROBE_DEFER);
> +
> + map = syscon_node_to_regmap(np);
> + if (IS_ERR(map)) {
> + pr_err("no syscon regmap\n");
> + return;
> + }
> + /*
> + Â* We check that the regmap works on this very first access,
> + Â* but as this is an MMIO-backed regmap, subsequent regmap
> + Â* access is not going to fail and we skip error checks from
> + Â* this point.
> + Â*/
> + ret = regmap_read(map, ASPEED_STRAP, &val);
> + if (ret) {
> + pr_err("failed to read strapping register\n");
> + return;
> + }
> +
> + aspeed_clk_data->num = ASPEED_NUM_CLKS;
> + ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, aspeed_clk_data);
> + if (ret)
> + pr_err("failed to add DT provider: %d\n", ret);
> +};
> +CLK_OF_DECLARE_DRIVER(aspeed_cc_g5, "aspeed,ast2500-scu", aspeed_cc_init);
> +CLK_OF_DECLARE_DRIVER(aspeed_cc_g4, "aspeed,ast2400-scu", aspeed_cc_init);
> diff --git a/include/dt-bindings/clock/aspeed-clock.h b/include/dt-bindings/clock/aspeed-clock.h
> new file mode 100644
> index 000000000000..4a99421d77c8
> --- /dev/null
> +++ b/include/dt-bindings/clock/aspeed-clock.h
> @@ -0,0 +1,42 @@
> +#ifndef DT_BINDINGS_ASPEED_CLOCK_H
> +#define DT_BINDINGS_ASPEED_CLOCK_H
> +
> +#define ASPEED_CLK_GATE_ECLK 0
> +#define ASPEED_CLK_GATE_GCLK 1
> +#define ASPEED_CLK_GATE_MCLK 2
> +#define ASPEED_CLK_GATE_VCLK 3
> +#define ASPEED_CLK_GATE_BCLK 4
> +#define ASPEED_CLK_GATE_DCLK 5
> +#define ASPEED_CLK_GATE_REFCLK 6
> +#define ASPEED_CLK_GATE_USBPORT2CLK 7
> +#define ASPEED_CLK_GATE_LCLK 8
> +#define ASPEED_CLK_GATE_USBUHCICLK 9
> +#define ASPEED_CLK_GATE_D1CLK 10
> +#define ASPEED_CLK_GATE_YCLK 11
> +#define ASPEED_CLK_GATE_USBPORT1CLK 12
> +#define ASPEED_CLK_GATE_UART1CLK 13
> +#define ASPEED_CLK_GATE_UART2CLK 14
> +#define ASPEED_CLK_GATE_UART5CLK 15
> +#define ASPEED_CLK_GATE_ESPICLK 16
> +#define ASPEED_CLK_GATE_MAC1CLK 17
> +#define ASPEED_CLK_GATE_MAC2CLK 18
> +#define ASPEED_CLK_GATE_RSACLK 19
> +#define ASPEED_CLK_GATE_UART3CLK 20
> +#define ASPEED_CLK_GATE_UART4CLK 21
> +#define ASPEED_CLK_GATE_SDCLKCLK 22
> +#define ASPEED_CLK_GATE_LHCCLK 23
> +#define ASPEED_CLK_HPLL 24
> +#define ASPEED_CLK_AHB 25
> +#define ASPEED_CLK_APB 26
> +#define ASPEED_CLK_UART 27
> +#define ASPEED_CLK_SDIO 28
> +#define ASPEED_CLK_ECLK 29
> +#define ASPEED_CLK_ECLK_MUX 30
> +#define ASPEED_CLK_LHCLK 31
> +#define ASPEED_CLK_MAC 32
> +#define ASPEED_CLK_BCLK 33
> +#define ASPEED_CLK_MPLL 34
> +
> +#define ASPEED_NUM_CLKS 35
> +
> +#endif

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