Add clock driver for meson #278

terryzbai · 2024-11-01T06:06:31Z

This clock driver configures all clocks as needed at boot time. The initial configurations are parsed from device tree with a python script (which will replaced with either Zig or Rust) and saved as a C header file to be accessed by clock driver.

The design of clock driver is derived from Linux Common Clock Framework (CCF) that unifies client interfaces and key data structures but simplified for modularity and maintainability. Additionally, clock definitions and operations are implemented as static to avoid dynamic memory allocation and other dangerous behaviours.

The current implementation assumes that all client requests are safe and compatible with the existing configurations, especially for clk_set_rate(), which simply adjust clock rates or propagate one level up to parent clock without any checking. A virtualiser is probably needed to manage requests according to the safety policy. determine_rate() and round_rate() need to be implemented to consider more complicated cases, such as multiple clock consumers requesting different frequencies, and dynamically clock scaling for power management.

Linux clock driver is the main reference but it is not always compatible with what described in the datasheet, and it could go through some obscure code somewhere, so there might be some unknown errors in my code.

~~The clock driver for maaxboard is in progress and coming soon.~~
The implementation for maaxboard is also ready.

wom-bat

These are too close to the Linux drivers. We don't need to provide a run-time interface for different clocks, as any sDDF system runs only on a single SoC --- so get rid of all the ..._ops structures and call the functions directly.

Plus please make sure all lines are under 80 chars wide, and add copyright and SPDX Licence tags where they;re missing. Also remember to sign-off your commit messages.

wom-bat · 2024-11-14T22:44:32Z

drivers/clk/clk-operations.c

+#include <sddf/timer/client.h>
+#include <sddf/util/printf.h>
+
+int reg_write(uint64_t base, uint32_t offset, uint32_t val)


Make static inline and in header

wom-bat · 2024-11-14T22:44:58Z

drivers/clk/clk-operations.c

+    return 0;
+}
+
+int regmap_update_bits(uint64_t base, uint32_t offset, uint8_t shift, uint8_t width, uint32_t val)


Make static inline and in header

wom-bat · 2024-11-14T22:45:37Z

drivers/clk/clk-operations.c

+    return 0;
+}
+
+int regmap_read_bits(uint64_t base, uint32_t offset, uint8_t shift, uint8_t width)


Make static inline; maybe should be uint32_t rather than int

wom-bat · 2024-11-14T22:47:37Z

drivers/clk/clk-operations.c

+    return reg_val;
+}
+
+int regmap_mux_update_bits(uint64_t base, uint32_t offset, uint8_t shift, uint32_t mask, uint32_t val)


You can probably abstract all the regmap_xxx_update functions into a single set instead of having separate mux and ordinary ones

wom-bat · 2024-11-14T22:48:26Z

drivers/clk/clk-operations.c

+    return reg_val;
+}
+
+static int clk_gate_enable(struct clk *clk)


Can be static inline

wom-bat · 2024-11-14T23:17:58Z

drivers/clk/meson/clk-measure.c

@@ -0,0 +1,230 @@
+/*
+ *
+ * This program is derived from:


Add SPDX licence id

wom-bat · 2024-11-14T23:21:09Z

drivers/clk/meson/clk-meson.c

+    return regmap_read_bits(base, parm.reg_off, parm.shift, parm.width);
+}
+
+/* TODO: Replace this doggy dealy() with a standard interface */


delay not dealy

wom-bat · 2024-11-14T23:21:42Z

drivers/clk/meson/clk-meson.c

+    int i;
+    for (i = 0; i < num_regs; i++) {
+        reg_write(base, regs[i].reg, regs[i].def);
+        /* TODO: delay is needed */


Is this TODO not already done?

wom-bat · 2024-11-14T23:25:58Z

drivers/clk/meson/clk-meson.c

+    regmap_update_bits(clk->base, data->sdm.reg_off, data->sdm.shift, data->sdm.width, sdm);
+    regmap_update_bits(clk->base, data->n2.reg_off, data->n2.shift, data->n2.width, n2);
+
+    /* volatile uint32_t *clk_reg = ((void *)clk_base + data->sdm.reg_off); */


wom-bat · 2024-11-14T23:26:49Z

drivers/clk/meson/clk.c

+        clk->hw.init->ops->set_rate(clk, req_rate, prate);
+        *rate = req_rate;
+        return 0;
+    } else {


Else not needed

This implementation includes all clock definitions, basic operations of clock compoents, as well as interfaces to interact with clicnets via PPC. Client should be able to enable/disable a specific gate clock or query the current clock rate by passing the corresponding clock identifier, which is listed in g12a-bindings.h. set_rate() assumes that the rate requst is valid and compatible with the current configurations. Complete implementation that considers more incompatible requests will come in the future when dynamic clock configuration is necessary in lionsos Signed-off-by: Terry Bai <[email protected]>

Signed-off-by: Terry Bai <[email protected]>

Add clock driver for maaxboard. This commit includes all clock component definitions, basic operations, and a simple test on maaxboard. Scripts are added in build systems. A few files are reorganised for reuse Signed-off-by: Terry Bai <[email protected]>

Signed-off-by: Terry Bai <[email protected]>

This commit includes modifiation to the interfaces, primarily for set/get rate, which return error state as well as final rate. More tests are conducted to verify the basic operations of types of clock components. A few bugs are fixed as well. Signed-off-by: Terry Bai <[email protected]>

This commit fixed style and license issues Signed-off-by: Terry Bai <[email protected]>

This commit replaces all platform-dependent data types with fix-sized types, and unifies the return values of interfaces as signed integers. The return value 0 indicates the success on the request to clock driver, and negative values indicate the failure reasons. Signed-off-by: Terry Bai <[email protected]>

Abstract a set of regmap_* operations by combining mux-specific ones and ordinary ones Signed-off-by: Terry Bai <[email protected]>

Add clk_get_parent() and clk_set_parent() interfaces for the clients. Fixed several logic issues in related implementations. More clock component definition checkings and fixup. Signed-off-by: Terry Bai <[email protected]>

This commit adds set_rate() implementations for maaxboard. Now clocks can be set to target rate at initialisation time and configured dynamically. Signed-off-by: Terry Bai <[email protected]>

This commit reorgnises source files to allow more code to be shared for multiple boards. Refactor makefiles: - move objectives to clk_driver directory - use built-in CFLAGS in rules Temporary fixup for a zig build issue: create_clk_config.py cannot find the lazypath `zig-out/bin` when executing. The current solution is to create an install directory in advance, but it would be a bit of trouble to find the generated header file if someone want to read or modify it. Moved clock specifier binding files to `include/sddf/clk`, so the clients will be able to configure clocks with macro constants Signed-off-by: Terry Bai <[email protected]>

terryzbai force-pushed the clk_driver branch 2 times, most recently from 642cb84 to d53cb39 Compare November 1, 2024 06:28

terryzbai marked this pull request as draft November 4, 2024 06:32

wom-bat requested changes Nov 14, 2024

View reviewed changes

terryzbai force-pushed the clk_driver branch from ef8af8f to bd71cc8 Compare November 15, 2024 04:47

terryzbai added 5 commits November 18, 2024 12:07

add Makefile

1e28903

Signed-off-by: Terry Bai <[email protected]>

Clock driver for maaxboard

1f03995

Add clock driver for maaxboard. This commit includes all clock component definitions, basic operations, and a simple test on maaxboard. Scripts are added in build systems. A few files are reorganised for reuse Signed-off-by: Terry Bai <[email protected]>

Clk: fix style

06bd8b6

Signed-off-by: Terry Bai <[email protected]>

terryzbai force-pushed the clk_driver branch 2 times, most recently from 160af1b to 3ec98a8 Compare November 18, 2024 01:25

clk: fix style and add licenses

1acc8de

This commit fixed style and license issues Signed-off-by: Terry Bai <[email protected]>

terryzbai force-pushed the clk_driver branch 2 times, most recently from b13868e to 2007cd7 Compare November 18, 2024 05:29

terryzbai force-pushed the clk_driver branch from 2007cd7 to 0a6c664 Compare November 18, 2024 05:35

terryzbai added 4 commits November 18, 2024 17:05

clk: combine regmap_* and regmap_mux_* operations

d8a400c

Abstract a set of regmap_* operations by combining mux-specific ones and ordinary ones Signed-off-by: Terry Bai <[email protected]>

clk: add get/set parent interfaces

e38a2d3

Add clk_get_parent() and clk_set_parent() interfaces for the clients. Fixed several logic issues in related implementations. More clock component definition checkings and fixup. Signed-off-by: Terry Bai <[email protected]>

clk: set_rate for maaxboard clocks

38d9f73

This commit adds set_rate() implementations for maaxboard. Now clocks can be set to target rate at initialisation time and configured dynamically. Signed-off-by: Terry Bai <[email protected]>

terryzbai mentioned this pull request Nov 21, 2024

I2C: Add real clock control #175

Open

terryzbai marked this pull request as ready for review November 21, 2024 01:44

terryzbai requested a review from wom-bat November 21, 2024 01:46

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Add clock driver for meson #278

Add clock driver for meson #278

terryzbai commented Nov 1, 2024 •

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Add clock driver for meson #278

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terryzbai commented Nov 1, 2024 • edited Loading

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terryzbai commented Nov 1, 2024 •

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