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linux/drivers/clk/baikal-t1/ccu-div.h

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clk: Add Baikal-T1 CCU Dividers driver Nearly each Baikal-T1 IP-core is supposed to have a clock source of particular frequency. But since there are greater than five IP-blocks embedded into the SoC, the CCU PLLs can't fulfill all the needs. Baikal-T1 CCU provides a set of fixed and configurable clock dividers in order to generate a necessary signal for each chip sub-block. This driver creates the of-based hardware clocks for each divider available in Baikal-T1 CCU. The same way as for PLLs we split the functionality up into the clocks operations (gate, ungate, set rate, etc) and hardware clocks declaration/registration procedures. In accordance with the CCU documentation all its dividers are distributed into two CCU sub-blocks: AXI-bus and system devices reference clocks. The former sub-block is used to supply the clocks for AXI-bus interfaces (AXI clock domains) and the later one provides the SoC IP-cores reference clocks. Each sub-block is represented by a dedicated DT node, so they have different compatible strings to distinguish one from another. For some reason CCU provides the dividers of different types. Some dividers can be gateable some can't, some are fixed while the others are variable, some have special divider' limitations, some've got a non-standard register layout and so on. In order to cover all of these cases the hardware clocks driver is designed with an info-descriptor pattern. So there are special static descriptors declared for the dividers of each type with additional flags describing the block peculiarity. These descriptors are then used to create hardware clocks with proper operations. Some CCU dividers provide a way to reset a domain they generate a clock for. So the CCU AXI-bus and CCU system devices clock drivers also perform the reset controller registration. Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Rob Herring <robh+dt@kernel.org> Cc: linux-mips@vger.kernel.org Cc: devicetree@vger.kernel.org Link: https://lore.kernel.org/r/20200526222056.18072-5-Sergey.Semin@baikalelectronics.ru [sboyd@kernel.org: Drop return from void function, silence sparse warnings about initializing structs with NULL vs. integer] Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2020-05-27 06:20:56 +08:00
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2020 BAIKAL ELECTRONICS, JSC
*
* Baikal-T1 CCU Dividers interface driver
*/
#ifndef __CLK_BT1_CCU_DIV_H__
#define __CLK_BT1_CCU_DIV_H__
#include <linux/clk-provider.h>
#include <linux/spinlock.h>
#include <linux/regmap.h>
#include <linux/bits.h>
#include <linux/of.h>
clk: baikal-t1: Add shared xGMAC ref/ptp clocks internal parent Baikal-T1 CCU reference manual says that both xGMAC reference and xGMAC PTP clocks are generated by two different wrappers with the same constant divider thus each producing a 156.25 MHz signal. But for some reason both of these clock sources are gated by a single switch-flag in the CCU registers space - CCU_SYS_XGMAC_BASE.BIT(0). In order to make the clocks handled independently we need to define a shared parental gate so the base clock signal would be switched off only if both of the child-clocks are disabled. Note the ID is intentionally set to -2 since we are going to add a one more internal clock identifier in the next commit. Fixes: 353afa3a8d2e ("clk: Add Baikal-T1 CCU Dividers driver") Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Link: https://lore.kernel.org/r/20220929225402.9696-4-Sergey.Semin@baikalelectronics.ru Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2022-09-30 06:53:57 +08:00
/*
* CCU Divider private clock IDs
clk: baikal-t1: Add SATA internal ref clock buffer It turns out the internal SATA reference clock signal will stay unavailable for the SATA interface consumer until the buffer on it's way is ungated. So aside with having the actual clock divider enabled we need to ungate a buffer placed on the signal way to the SATA controller (most likely some rudiment from the initial SoC release). Seeing the switch flag is placed in the same register as the SATA-ref clock divider at a non-standard ffset, let's implement it as a separate clock controller with the set-rate propagation to the parental clock divider wrapper. As such we'll be able to disable/enable and still change the original clock source rate. Fixes: 353afa3a8d2e ("clk: Add Baikal-T1 CCU Dividers driver") Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Link: https://lore.kernel.org/r/20220929225402.9696-5-Sergey.Semin@baikalelectronics.ru Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2022-09-30 06:53:58 +08:00
* @CCU_SYS_SATA_CLK: CCU SATA internal clock
clk: baikal-t1: Add shared xGMAC ref/ptp clocks internal parent Baikal-T1 CCU reference manual says that both xGMAC reference and xGMAC PTP clocks are generated by two different wrappers with the same constant divider thus each producing a 156.25 MHz signal. But for some reason both of these clock sources are gated by a single switch-flag in the CCU registers space - CCU_SYS_XGMAC_BASE.BIT(0). In order to make the clocks handled independently we need to define a shared parental gate so the base clock signal would be switched off only if both of the child-clocks are disabled. Note the ID is intentionally set to -2 since we are going to add a one more internal clock identifier in the next commit. Fixes: 353afa3a8d2e ("clk: Add Baikal-T1 CCU Dividers driver") Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Link: https://lore.kernel.org/r/20220929225402.9696-4-Sergey.Semin@baikalelectronics.ru Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2022-09-30 06:53:57 +08:00
* @CCU_SYS_XGMAC_CLK: CCU XGMAC internal clock
*/
clk: baikal-t1: Add SATA internal ref clock buffer It turns out the internal SATA reference clock signal will stay unavailable for the SATA interface consumer until the buffer on it's way is ungated. So aside with having the actual clock divider enabled we need to ungate a buffer placed on the signal way to the SATA controller (most likely some rudiment from the initial SoC release). Seeing the switch flag is placed in the same register as the SATA-ref clock divider at a non-standard ffset, let's implement it as a separate clock controller with the set-rate propagation to the parental clock divider wrapper. As such we'll be able to disable/enable and still change the original clock source rate. Fixes: 353afa3a8d2e ("clk: Add Baikal-T1 CCU Dividers driver") Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Link: https://lore.kernel.org/r/20220929225402.9696-5-Sergey.Semin@baikalelectronics.ru Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2022-09-30 06:53:58 +08:00
#define CCU_SYS_SATA_CLK -1
clk: baikal-t1: Add shared xGMAC ref/ptp clocks internal parent Baikal-T1 CCU reference manual says that both xGMAC reference and xGMAC PTP clocks are generated by two different wrappers with the same constant divider thus each producing a 156.25 MHz signal. But for some reason both of these clock sources are gated by a single switch-flag in the CCU registers space - CCU_SYS_XGMAC_BASE.BIT(0). In order to make the clocks handled independently we need to define a shared parental gate so the base clock signal would be switched off only if both of the child-clocks are disabled. Note the ID is intentionally set to -2 since we are going to add a one more internal clock identifier in the next commit. Fixes: 353afa3a8d2e ("clk: Add Baikal-T1 CCU Dividers driver") Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Link: https://lore.kernel.org/r/20220929225402.9696-4-Sergey.Semin@baikalelectronics.ru Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2022-09-30 06:53:57 +08:00
#define CCU_SYS_XGMAC_CLK -2
clk: Add Baikal-T1 CCU Dividers driver Nearly each Baikal-T1 IP-core is supposed to have a clock source of particular frequency. But since there are greater than five IP-blocks embedded into the SoC, the CCU PLLs can't fulfill all the needs. Baikal-T1 CCU provides a set of fixed and configurable clock dividers in order to generate a necessary signal for each chip sub-block. This driver creates the of-based hardware clocks for each divider available in Baikal-T1 CCU. The same way as for PLLs we split the functionality up into the clocks operations (gate, ungate, set rate, etc) and hardware clocks declaration/registration procedures. In accordance with the CCU documentation all its dividers are distributed into two CCU sub-blocks: AXI-bus and system devices reference clocks. The former sub-block is used to supply the clocks for AXI-bus interfaces (AXI clock domains) and the later one provides the SoC IP-cores reference clocks. Each sub-block is represented by a dedicated DT node, so they have different compatible strings to distinguish one from another. For some reason CCU provides the dividers of different types. Some dividers can be gateable some can't, some are fixed while the others are variable, some have special divider' limitations, some've got a non-standard register layout and so on. In order to cover all of these cases the hardware clocks driver is designed with an info-descriptor pattern. So there are special static descriptors declared for the dividers of each type with additional flags describing the block peculiarity. These descriptors are then used to create hardware clocks with proper operations. Some CCU dividers provide a way to reset a domain they generate a clock for. So the CCU AXI-bus and CCU system devices clock drivers also perform the reset controller registration. Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Rob Herring <robh+dt@kernel.org> Cc: linux-mips@vger.kernel.org Cc: devicetree@vger.kernel.org Link: https://lore.kernel.org/r/20200526222056.18072-5-Sergey.Semin@baikalelectronics.ru [sboyd@kernel.org: Drop return from void function, silence sparse warnings about initializing structs with NULL vs. integer] Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2020-05-27 06:20:56 +08:00
/*
* CCU Divider private flags
clk: baikal-t1: Convert to platform device driver In accordance with the way the MIPS platform is normally design there are only six clock sources which need to be available on the kernel start in order to one end up booting correctly: + CPU PLL: needed by the r4k and MIPS GIC timer drivers. The former one is initialized by the arch code, while the later one is implemented in the mips-gic-timer.c driver as the OF-declared timer. + PCIe PLL: required as a parental clock source for the APB/timer domains. + APB clock: needed in order to access all the SoC CSRs at least for the timer OF-declared drivers. + APB Timer{0-2} clocks: these are the DW APB timers which drivers dw_apb_timer_of.c are implemented as the OF-declared timers. So as long as the clocks above are available early the kernel will normally work. Let's convert the Baikal-T1 CCU drivers to the platform device drivers keeping that in mind. Generally speaking the conversion isn't that complicated since the driver infrastructure has been designed as flexible enough for that. First we need to add a new PLL/Divider clock features flag which indicates the corresponding clock source as a basic one and that clock sources will be available on the kernel early boot stages. Second the internal PLL/Divider descriptors need to be initialized with -EPROBE_DEFER value as the corresponding clock source is unavailable at the early stages. They will be allocated and initialized on the Baikal-T1 clock platform driver probe procedure. Finally the already available PLL/Divider init functions need to be split up into two ones: init procedure performed in the framework of the OF-declared clock initialization (of_clk_init()), and the probe procedure called by the platform devices bus driver. Note the later method will just continue the system clocks initialization started in the former one. Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Link: https://lore.kernel.org/r/20220929225402.9696-9-Sergey.Semin@baikalelectronics.ru [sboyd@kernel.org: Remove module things because the Kconfig is still bool] Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2022-09-30 06:54:02 +08:00
* @CCU_DIV_BASIC: Basic divider clock required by the kernel as early as
* possible.
clk: Add Baikal-T1 CCU Dividers driver Nearly each Baikal-T1 IP-core is supposed to have a clock source of particular frequency. But since there are greater than five IP-blocks embedded into the SoC, the CCU PLLs can't fulfill all the needs. Baikal-T1 CCU provides a set of fixed and configurable clock dividers in order to generate a necessary signal for each chip sub-block. This driver creates the of-based hardware clocks for each divider available in Baikal-T1 CCU. The same way as for PLLs we split the functionality up into the clocks operations (gate, ungate, set rate, etc) and hardware clocks declaration/registration procedures. In accordance with the CCU documentation all its dividers are distributed into two CCU sub-blocks: AXI-bus and system devices reference clocks. The former sub-block is used to supply the clocks for AXI-bus interfaces (AXI clock domains) and the later one provides the SoC IP-cores reference clocks. Each sub-block is represented by a dedicated DT node, so they have different compatible strings to distinguish one from another. For some reason CCU provides the dividers of different types. Some dividers can be gateable some can't, some are fixed while the others are variable, some have special divider' limitations, some've got a non-standard register layout and so on. In order to cover all of these cases the hardware clocks driver is designed with an info-descriptor pattern. So there are special static descriptors declared for the dividers of each type with additional flags describing the block peculiarity. These descriptors are then used to create hardware clocks with proper operations. Some CCU dividers provide a way to reset a domain they generate a clock for. So the CCU AXI-bus and CCU system devices clock drivers also perform the reset controller registration. Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Rob Herring <robh+dt@kernel.org> Cc: linux-mips@vger.kernel.org Cc: devicetree@vger.kernel.org Link: https://lore.kernel.org/r/20200526222056.18072-5-Sergey.Semin@baikalelectronics.ru [sboyd@kernel.org: Drop return from void function, silence sparse warnings about initializing structs with NULL vs. integer] Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2020-05-27 06:20:56 +08:00
* @CCU_DIV_SKIP_ONE: Due to some reason divider can't be set to 1.
* It can be 0 though, which is functionally the same.
* @CCU_DIV_SKIP_ONE_TO_THREE: For some reason divider can't be within [1,3].
* It can be either 0 or greater than 3.
* @CCU_DIV_LOCK_SHIFTED: Find lock-bit at non-standard position.
clk: baikal-t1: Move reset-controls code into a dedicated module Before adding the directly controlled resets support it's reasonable to move the existing resets control functionality into a dedicated object for the sake of the CCU dividers clock driver simplification. After the new functionality was added clk-ccu-div.c would have got to a mixture of the weakly dependent clocks and resets methods. Splitting the methods up into the two objects will make the code easier to read and maintain. It shall also improve the code scalability (though hopefully we won't need this part that much in the future). The reset control functionality is now implemented in the framework of a single unit since splitting it up doesn't make much sense due to relatively simple reset operations. The ccu-rst.c has been designed to be looking like ccu-div.c or ccu-pll.c with two globally available methods for the sake of the code unification and better code readability. This commit doesn't provide any change in the CCU reset implementation semantics. As before the driver will support the trigger-like CCU resets only, which are responsible for the AXI-bus, APB-bus and SATA-ref blocks reset. The assert/de-assert-capable reset controls support will be added in the next commit. Note the CCU Clock dividers and resets functionality split up was possible due to not having any side-effects (at least we didn't found ones) of the regmap-based concurrent access of the common CCU dividers/reset CSRs. Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de> Link: https://lore.kernel.org/r/20220929225402.9696-6-Sergey.Semin@baikalelectronics.ru Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2022-09-30 06:53:59 +08:00
* @CCU_DIV_RESET_DOMAIN: There is a clock domain reset handle.
clk: Add Baikal-T1 CCU Dividers driver Nearly each Baikal-T1 IP-core is supposed to have a clock source of particular frequency. But since there are greater than five IP-blocks embedded into the SoC, the CCU PLLs can't fulfill all the needs. Baikal-T1 CCU provides a set of fixed and configurable clock dividers in order to generate a necessary signal for each chip sub-block. This driver creates the of-based hardware clocks for each divider available in Baikal-T1 CCU. The same way as for PLLs we split the functionality up into the clocks operations (gate, ungate, set rate, etc) and hardware clocks declaration/registration procedures. In accordance with the CCU documentation all its dividers are distributed into two CCU sub-blocks: AXI-bus and system devices reference clocks. The former sub-block is used to supply the clocks for AXI-bus interfaces (AXI clock domains) and the later one provides the SoC IP-cores reference clocks. Each sub-block is represented by a dedicated DT node, so they have different compatible strings to distinguish one from another. For some reason CCU provides the dividers of different types. Some dividers can be gateable some can't, some are fixed while the others are variable, some have special divider' limitations, some've got a non-standard register layout and so on. In order to cover all of these cases the hardware clocks driver is designed with an info-descriptor pattern. So there are special static descriptors declared for the dividers of each type with additional flags describing the block peculiarity. These descriptors are then used to create hardware clocks with proper operations. Some CCU dividers provide a way to reset a domain they generate a clock for. So the CCU AXI-bus and CCU system devices clock drivers also perform the reset controller registration. Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Rob Herring <robh+dt@kernel.org> Cc: linux-mips@vger.kernel.org Cc: devicetree@vger.kernel.org Link: https://lore.kernel.org/r/20200526222056.18072-5-Sergey.Semin@baikalelectronics.ru [sboyd@kernel.org: Drop return from void function, silence sparse warnings about initializing structs with NULL vs. integer] Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2020-05-27 06:20:56 +08:00
*/
clk: baikal-t1: Convert to platform device driver In accordance with the way the MIPS platform is normally design there are only six clock sources which need to be available on the kernel start in order to one end up booting correctly: + CPU PLL: needed by the r4k and MIPS GIC timer drivers. The former one is initialized by the arch code, while the later one is implemented in the mips-gic-timer.c driver as the OF-declared timer. + PCIe PLL: required as a parental clock source for the APB/timer domains. + APB clock: needed in order to access all the SoC CSRs at least for the timer OF-declared drivers. + APB Timer{0-2} clocks: these are the DW APB timers which drivers dw_apb_timer_of.c are implemented as the OF-declared timers. So as long as the clocks above are available early the kernel will normally work. Let's convert the Baikal-T1 CCU drivers to the platform device drivers keeping that in mind. Generally speaking the conversion isn't that complicated since the driver infrastructure has been designed as flexible enough for that. First we need to add a new PLL/Divider clock features flag which indicates the corresponding clock source as a basic one and that clock sources will be available on the kernel early boot stages. Second the internal PLL/Divider descriptors need to be initialized with -EPROBE_DEFER value as the corresponding clock source is unavailable at the early stages. They will be allocated and initialized on the Baikal-T1 clock platform driver probe procedure. Finally the already available PLL/Divider init functions need to be split up into two ones: init procedure performed in the framework of the OF-declared clock initialization (of_clk_init()), and the probe procedure called by the platform devices bus driver. Note the later method will just continue the system clocks initialization started in the former one. Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Link: https://lore.kernel.org/r/20220929225402.9696-9-Sergey.Semin@baikalelectronics.ru [sboyd@kernel.org: Remove module things because the Kconfig is still bool] Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2022-09-30 06:54:02 +08:00
#define CCU_DIV_BASIC BIT(0)
clk: Add Baikal-T1 CCU Dividers driver Nearly each Baikal-T1 IP-core is supposed to have a clock source of particular frequency. But since there are greater than five IP-blocks embedded into the SoC, the CCU PLLs can't fulfill all the needs. Baikal-T1 CCU provides a set of fixed and configurable clock dividers in order to generate a necessary signal for each chip sub-block. This driver creates the of-based hardware clocks for each divider available in Baikal-T1 CCU. The same way as for PLLs we split the functionality up into the clocks operations (gate, ungate, set rate, etc) and hardware clocks declaration/registration procedures. In accordance with the CCU documentation all its dividers are distributed into two CCU sub-blocks: AXI-bus and system devices reference clocks. The former sub-block is used to supply the clocks for AXI-bus interfaces (AXI clock domains) and the later one provides the SoC IP-cores reference clocks. Each sub-block is represented by a dedicated DT node, so they have different compatible strings to distinguish one from another. For some reason CCU provides the dividers of different types. Some dividers can be gateable some can't, some are fixed while the others are variable, some have special divider' limitations, some've got a non-standard register layout and so on. In order to cover all of these cases the hardware clocks driver is designed with an info-descriptor pattern. So there are special static descriptors declared for the dividers of each type with additional flags describing the block peculiarity. These descriptors are then used to create hardware clocks with proper operations. Some CCU dividers provide a way to reset a domain they generate a clock for. So the CCU AXI-bus and CCU system devices clock drivers also perform the reset controller registration. Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Rob Herring <robh+dt@kernel.org> Cc: linux-mips@vger.kernel.org Cc: devicetree@vger.kernel.org Link: https://lore.kernel.org/r/20200526222056.18072-5-Sergey.Semin@baikalelectronics.ru [sboyd@kernel.org: Drop return from void function, silence sparse warnings about initializing structs with NULL vs. integer] Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2020-05-27 06:20:56 +08:00
#define CCU_DIV_SKIP_ONE BIT(1)
#define CCU_DIV_SKIP_ONE_TO_THREE BIT(2)
#define CCU_DIV_LOCK_SHIFTED BIT(3)
#define CCU_DIV_RESET_DOMAIN BIT(4)
/*
* enum ccu_div_type - CCU Divider types
* @CCU_DIV_VAR: Clocks gate with variable divider.
* @CCU_DIV_GATE: Clocks gate with fixed divider.
clk: baikal-t1: Add SATA internal ref clock buffer It turns out the internal SATA reference clock signal will stay unavailable for the SATA interface consumer until the buffer on it's way is ungated. So aside with having the actual clock divider enabled we need to ungate a buffer placed on the signal way to the SATA controller (most likely some rudiment from the initial SoC release). Seeing the switch flag is placed in the same register as the SATA-ref clock divider at a non-standard ffset, let's implement it as a separate clock controller with the set-rate propagation to the parental clock divider wrapper. As such we'll be able to disable/enable and still change the original clock source rate. Fixes: 353afa3a8d2e ("clk: Add Baikal-T1 CCU Dividers driver") Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Link: https://lore.kernel.org/r/20220929225402.9696-5-Sergey.Semin@baikalelectronics.ru Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2022-09-30 06:53:58 +08:00
* @CCU_DIV_BUF: Clock gate with no divider.
clk: Add Baikal-T1 CCU Dividers driver Nearly each Baikal-T1 IP-core is supposed to have a clock source of particular frequency. But since there are greater than five IP-blocks embedded into the SoC, the CCU PLLs can't fulfill all the needs. Baikal-T1 CCU provides a set of fixed and configurable clock dividers in order to generate a necessary signal for each chip sub-block. This driver creates the of-based hardware clocks for each divider available in Baikal-T1 CCU. The same way as for PLLs we split the functionality up into the clocks operations (gate, ungate, set rate, etc) and hardware clocks declaration/registration procedures. In accordance with the CCU documentation all its dividers are distributed into two CCU sub-blocks: AXI-bus and system devices reference clocks. The former sub-block is used to supply the clocks for AXI-bus interfaces (AXI clock domains) and the later one provides the SoC IP-cores reference clocks. Each sub-block is represented by a dedicated DT node, so they have different compatible strings to distinguish one from another. For some reason CCU provides the dividers of different types. Some dividers can be gateable some can't, some are fixed while the others are variable, some have special divider' limitations, some've got a non-standard register layout and so on. In order to cover all of these cases the hardware clocks driver is designed with an info-descriptor pattern. So there are special static descriptors declared for the dividers of each type with additional flags describing the block peculiarity. These descriptors are then used to create hardware clocks with proper operations. Some CCU dividers provide a way to reset a domain they generate a clock for. So the CCU AXI-bus and CCU system devices clock drivers also perform the reset controller registration. Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Rob Herring <robh+dt@kernel.org> Cc: linux-mips@vger.kernel.org Cc: devicetree@vger.kernel.org Link: https://lore.kernel.org/r/20200526222056.18072-5-Sergey.Semin@baikalelectronics.ru [sboyd@kernel.org: Drop return from void function, silence sparse warnings about initializing structs with NULL vs. integer] Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2020-05-27 06:20:56 +08:00
* @CCU_DIV_FIXED: Ungateable clock with fixed divider.
*/
enum ccu_div_type {
CCU_DIV_VAR,
CCU_DIV_GATE,
clk: baikal-t1: Add SATA internal ref clock buffer It turns out the internal SATA reference clock signal will stay unavailable for the SATA interface consumer until the buffer on it's way is ungated. So aside with having the actual clock divider enabled we need to ungate a buffer placed on the signal way to the SATA controller (most likely some rudiment from the initial SoC release). Seeing the switch flag is placed in the same register as the SATA-ref clock divider at a non-standard ffset, let's implement it as a separate clock controller with the set-rate propagation to the parental clock divider wrapper. As such we'll be able to disable/enable and still change the original clock source rate. Fixes: 353afa3a8d2e ("clk: Add Baikal-T1 CCU Dividers driver") Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Link: https://lore.kernel.org/r/20220929225402.9696-5-Sergey.Semin@baikalelectronics.ru Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2022-09-30 06:53:58 +08:00
CCU_DIV_BUF,
clk: Add Baikal-T1 CCU Dividers driver Nearly each Baikal-T1 IP-core is supposed to have a clock source of particular frequency. But since there are greater than five IP-blocks embedded into the SoC, the CCU PLLs can't fulfill all the needs. Baikal-T1 CCU provides a set of fixed and configurable clock dividers in order to generate a necessary signal for each chip sub-block. This driver creates the of-based hardware clocks for each divider available in Baikal-T1 CCU. The same way as for PLLs we split the functionality up into the clocks operations (gate, ungate, set rate, etc) and hardware clocks declaration/registration procedures. In accordance with the CCU documentation all its dividers are distributed into two CCU sub-blocks: AXI-bus and system devices reference clocks. The former sub-block is used to supply the clocks for AXI-bus interfaces (AXI clock domains) and the later one provides the SoC IP-cores reference clocks. Each sub-block is represented by a dedicated DT node, so they have different compatible strings to distinguish one from another. For some reason CCU provides the dividers of different types. Some dividers can be gateable some can't, some are fixed while the others are variable, some have special divider' limitations, some've got a non-standard register layout and so on. In order to cover all of these cases the hardware clocks driver is designed with an info-descriptor pattern. So there are special static descriptors declared for the dividers of each type with additional flags describing the block peculiarity. These descriptors are then used to create hardware clocks with proper operations. Some CCU dividers provide a way to reset a domain they generate a clock for. So the CCU AXI-bus and CCU system devices clock drivers also perform the reset controller registration. Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Rob Herring <robh+dt@kernel.org> Cc: linux-mips@vger.kernel.org Cc: devicetree@vger.kernel.org Link: https://lore.kernel.org/r/20200526222056.18072-5-Sergey.Semin@baikalelectronics.ru [sboyd@kernel.org: Drop return from void function, silence sparse warnings about initializing structs with NULL vs. integer] Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2020-05-27 06:20:56 +08:00
CCU_DIV_FIXED
};
/*
* struct ccu_div_init_data - CCU Divider initialization data
* @id: Clocks private identifier.
* @name: Clocks name.
* @parent_name: Parent clocks name in a fw node.
* @base: Divider register base address with respect to the sys_regs base.
* @sys_regs: Baikal-T1 System Controller registers map.
* @np: Pointer to the node describing the CCU Dividers.
* @type: CCU divider type (variable, fixed with and without gate).
* @width: Divider width if it's variable.
* @divider: Divider fixed value.
* @flags: CCU Divider clock flags.
* @features: CCU Divider private features.
*/
struct ccu_div_init_data {
unsigned int id;
const char *name;
const char *parent_name;
unsigned int base;
struct regmap *sys_regs;
struct device_node *np;
enum ccu_div_type type;
union {
unsigned int width;
unsigned int divider;
};
unsigned long flags;
unsigned long features;
};
/*
* struct ccu_div - CCU Divider descriptor
* @hw: clk_hw of the divider.
* @id: Clock private identifier.
* @reg_ctl: Divider control register base address.
* @sys_regs: Baikal-T1 System Controller registers map.
* @lock: Divider state change spin-lock.
* @mask: Divider field mask.
* @divider: Divider fixed value.
* @flags: Divider clock flags.
* @features: CCU Divider private features.
*/
struct ccu_div {
struct clk_hw hw;
unsigned int id;
unsigned int reg_ctl;
struct regmap *sys_regs;
spinlock_t lock;
union {
u32 mask;
unsigned int divider;
};
unsigned long flags;
unsigned long features;
};
#define to_ccu_div(_hw) container_of(_hw, struct ccu_div, hw)
static inline struct clk_hw *ccu_div_get_clk_hw(struct ccu_div *div)
{
return div ? &div->hw : NULL;
}
struct ccu_div *ccu_div_hw_register(const struct ccu_div_init_data *init);
void ccu_div_hw_unregister(struct ccu_div *div);
#endif /* __CLK_BT1_CCU_DIV_H__ */
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