| Message ID | 20240401-wpcm-clk-v11-3-379472961244@gmx.net (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | Nuvoton WPCM450 clock and reset driver | expand |
Quoting Jonathan Neuschäfer (2024-04-01 07:06:32) > This driver implements the following features w.r.t. the clock and reset > controller in the WPCM450 SoC: > > - It calculates the rates for all clocks managed by the clock controller > - It leaves the clock tree mostly unchanged, except that it enables/ > disables clock gates based on usage. > - It exposes the reset lines managed by the controller using the > Generic Reset Controller subsystem > > NOTE: If the driver and the corresponding devicetree node are present, > the driver will disable "unused" clocks. This is problem until > the clock relations are properly declared in the devicetree (in a > later patch). Until then, the clk_ignore_unused kernel parameter > can be used as a workaround. > > Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> > Reviewed-by: Joel Stanley <joel@jms.id.au> > --- > > I have considered converting this driver to a platform driver instead of > using CLK_OF_DECLARE, because platform drivers are generally the way > forward. However, the timer-npcm7xx driver used on the same platform > requires is initialized with TIMER_OF_DECLARE and thus requires the > clocks to be available earlier than a platform driver can provide them. In that case you can use CLK_OF_DECLARE_DRIVER(), register the clks needed for the timer driver to probe, and then put the rest of the clk registration in a normal platform driver. > diff --git a/drivers/clk/nuvoton/clk-wpcm450.c b/drivers/clk/nuvoton/clk-wpcm450.c > new file mode 100644 > index 00000000000000..9100c4b8a56483 > --- /dev/null > +++ b/drivers/clk/nuvoton/clk-wpcm450.c > @@ -0,0 +1,372 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Nuvoton WPCM450 clock and reset controller driver. > + * > + * Copyright (C) 2022 Jonathan Neuschäfer <j.neuschaefer@gmx.net> > + */ > + > +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt Isn't KBUILD_MODNAME an option already for dynamic debug? > + > +#include <linux/bitfield.h> > +#include <linux/clk-provider.h> > +#include <linux/io.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/of_address.h> > +#include <linux/reset-controller.h> > +#include <linux/reset/reset-simple.h> > +#include <linux/slab.h> > + [...] > + > +static const struct clk_parent_data default_parents[] = { > + { .name = "pll0" }, > + { .name = "pll1" }, > + { .name = "ref" }, > +}; > + > +static const struct clk_parent_data huart_parents[] = { > + { .fw_name = "ref" }, > + { .name = "refdiv2" }, Please remove all .name elements and use indexes or direct pointers. > +}; > + > +static const struct wpcm450_clksel_data clksel_data[] = { > + { "cpusel", default_parents, ARRAY_SIZE(default_parents), > + parent_table, 0, 2, -1, CLK_IS_CRITICAL }, > + { "clkout", default_parents, ARRAY_SIZE(default_parents), > + parent_table, 2, 2, -1, 0 }, > + { "usbphy", default_parents, ARRAY_SIZE(default_parents), > + parent_table, 6, 2, -1, 0 }, > + { "uartsel", default_parents, ARRAY_SIZE(default_parents), > + parent_table, 8, 2, WPCM450_CLK_USBPHY, 0 }, > + { "huartsel", huart_parents, ARRAY_SIZE(huart_parents), > + parent_table, 10, 1, -1, 0 }, > +}; > + > +static const struct clk_div_table div_fixed2[] = { > + { .val = 0, .div = 2 }, > + { } > +}; > + > +struct wpcm450_clkdiv_data { > + const char *name; > + struct clk_parent_data parent; > + int div_flags; > + const struct clk_div_table *table; > + int shift; > + int width; > + unsigned long flags; > +}; > + > +static struct wpcm450_clkdiv_data clkdiv_data_early[] = { > + { "refdiv2", { .name = "ref" }, 0, div_fixed2, 0, 0 }, > +}; > + > +static const struct wpcm450_clkdiv_data clkdiv_data[] = { > + { "cpu", { .name = "cpusel" }, 0, div_fixed2, 0, 0, CLK_IS_CRITICAL }, > + { "adcdiv", { .name = "ref" }, CLK_DIVIDER_POWER_OF_TWO, NULL, 28, 2, 0 }, > + { "apb", { .name = "ahb" }, CLK_DIVIDER_POWER_OF_TWO, NULL, 26, 2, 0 }, > + { "ahb", { .name = "cpu" }, CLK_DIVIDER_POWER_OF_TWO, NULL, 24, 2, 0 }, > + { "uart", { .name = "uartsel" }, 0, NULL, 16, 4, 0 }, > + { "ahb3", { .name = "ahb" }, CLK_DIVIDER_POWER_OF_TWO, NULL, 8, 2, 0 }, > +}; > + > +struct wpcm450_clken_data { > + const char *name; > + struct clk_parent_data parent; > + int bitnum; > + unsigned long flags; > +}; > + > +static const struct wpcm450_clken_data clken_data[] = { > + { "fiu", { .name = "ahb3" }, WPCM450_CLK_FIU, 0 }, This actually is { .index = 0, .name = "ahb3" } and that is a bad combination. struct clk_parent_data should only have .name as a fallback when there's an old binding out there that doesn't have the 'clocks' property for the clk provider node. There shouldn't be any .name property because this is new code and a new binding. > + { "xbus", { .name = "ahb3" }, WPCM450_CLK_XBUS, 0 }, > + { "kcs", { .name = "apb" }, WPCM450_CLK_KCS, 0 }, > + { "shm", { .name = "ahb3" }, WPCM450_CLK_SHM, 0 }, > + { "usb1", { .name = "ahb" }, WPCM450_CLK_USB1, 0 }, > + { "emc0", { .name = "ahb" }, WPCM450_CLK_EMC0, 0 }, > + { "emc1", { .name = "ahb" }, WPCM450_CLK_EMC1, 0 }, > + { "usb0", { .name = "ahb" }, WPCM450_CLK_USB0, 0 }, > + { "peci", { .name = "apb" }, WPCM450_CLK_PECI, 0 }, > + { "aes", { .name = "apb" }, WPCM450_CLK_AES, 0 }, > + { "uart0", { .name = "uart" }, WPCM450_CLK_UART0, 0 }, > + { "uart1", { .name = "uart" }, WPCM450_CLK_UART1, 0 }, > + { "smb2", { .name = "apb" }, WPCM450_CLK_SMB2, 0 }, > + { "smb3", { .name = "apb" }, WPCM450_CLK_SMB3, 0 }, > + { "smb4", { .name = "apb" }, WPCM450_CLK_SMB4, 0 }, > + { "smb5", { .name = "apb" }, WPCM450_CLK_SMB5, 0 }, > + { "huart", { .name = "huartsel" }, WPCM450_CLK_HUART, 0 }, > + { "pwm", { .name = "apb" }, WPCM450_CLK_PWM, 0 }, > + { "timer0", { .name = "refdiv2" }, WPCM450_CLK_TIMER0, 0 }, > + { "timer1", { .name = "refdiv2" }, WPCM450_CLK_TIMER1, 0 }, > + { "timer2", { .name = "refdiv2" }, WPCM450_CLK_TIMER2, 0 }, > + { "timer3", { .name = "refdiv2" }, WPCM450_CLK_TIMER3, 0 }, > + { "timer4", { .name = "refdiv2" }, WPCM450_CLK_TIMER4, 0 }, > + { "mft0", { .name = "apb" }, WPCM450_CLK_MFT0, 0 }, > + { "mft1", { .name = "apb" }, WPCM450_CLK_MFT1, 0 }, > + { "wdt", { .name = "refdiv2" }, WPCM450_CLK_WDT, 0 }, > + { "adc", { .name = "adcdiv" }, WPCM450_CLK_ADC, 0 }, > + { "sdio", { .name = "ahb" }, WPCM450_CLK_SDIO, 0 }, > + { "sspi", { .name = "apb" }, WPCM450_CLK_SSPI, 0 }, > + { "smb0", { .name = "apb" }, WPCM450_CLK_SMB0, 0 }, > + { "smb1", { .name = "apb" }, WPCM450_CLK_SMB1, 0 }, > +}; > + > +static DEFINE_SPINLOCK(wpcm450_clk_lock); > + > +/* > + * NOTE: Error handling is very rudimentary here. If the clock driver initial- > + * ization fails, the system is probably in bigger trouble than what is caused Don't break words across lines with hyphens. > + * by a few leaked resources. > + */ > + > +static void __init wpcm450_clk_init(struct device_node *np) > +{ > + struct clk_hw_onecell_data *clk_data; > + static struct clk_hw **hws; > + static struct clk_hw *hw; > + void __iomem *clk_base; > + int i, ret; > + struct reset_simple_data *reset; > + > + clk_base = of_iomap(np, 0); > + if (!clk_base) { > + pr_err("%pOFP: failed to map registers\n", np); > + of_node_put(np); > + return; > + } > + of_node_put(np); The 'np' is used later when registering PLLs. You can only put the node after it's no longer used. Also, you never got the node with of_node_get(), so putting it here actually causes an underflow on the refcount. Just remove all the get/puts instead. > + > + clk_data = kzalloc(struct_size(clk_data, hws, WPCM450_NUM_CLKS), GFP_KERNEL); > + if (!clk_data) > + return; > + > + clk_data->num = WPCM450_NUM_CLKS; [...] > + /* Reset controller */ > + reset = kzalloc(sizeof(*reset), GFP_KERNEL); > + if (!reset) > + return; > + reset->rcdev.owner = THIS_MODULE; > + reset->rcdev.nr_resets = WPCM450_NUM_RESETS; > + reset->rcdev.ops = &reset_simple_ops; > + reset->rcdev.of_node = np; > + reset->membase = clk_base + REG_IPSRST; > + ret = reset_controller_register(&reset->rcdev); > + if (ret) > + pr_err("Failed to register reset controller: %pe\n", ERR_PTR(ret)); It would be nicer to register this device as an auxiliary device with a single API call and then have all the resets exist in that file instead of this file. The driver would be put in drivers/reset/ as well. > + > + of_node_put(np); Drop this of_node_put()
Hi, On Fri, Apr 12, 2024 at 12:25:05AM -0700, Stephen Boyd wrote: > Quoting Jonathan Neuschäfer (2024-04-01 07:06:32) > > This driver implements the following features w.r.t. the clock and reset > > controller in the WPCM450 SoC: > > > > - It calculates the rates for all clocks managed by the clock controller > > - It leaves the clock tree mostly unchanged, except that it enables/ > > disables clock gates based on usage. > > - It exposes the reset lines managed by the controller using the > > Generic Reset Controller subsystem > > > > NOTE: If the driver and the corresponding devicetree node are present, > > the driver will disable "unused" clocks. This is problem until > > the clock relations are properly declared in the devicetree (in a > > later patch). Until then, the clk_ignore_unused kernel parameter > > can be used as a workaround. > > > > Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> > > Reviewed-by: Joel Stanley <joel@jms.id.au> > > --- > > > > I have considered converting this driver to a platform driver instead of > > using CLK_OF_DECLARE, because platform drivers are generally the way > > forward. However, the timer-npcm7xx driver used on the same platform > > requires is initialized with TIMER_OF_DECLARE and thus requires the > > clocks to be available earlier than a platform driver can provide them. > > In that case you can use CLK_OF_DECLARE_DRIVER(), register the clks > needed for the timer driver to probe, and then put the rest of the clk > registration in a normal platform driver. I'll give it a try. I'm not sure how to make it work correctly without calling (devm_)of_clk_add_hw_provider twice, though (once for the early clock, timer0; once for the rest). Another (probably simpler) approach seems be to declare a fixed-clock or fixed-factor-clock in the DT, and use that in the timer: refclk_div2: clock-div2 { compatible = "fixed-factor-clock"; clocks = <&refclk>; #clock-cells = <0>; clock-mult = <1>; clock-div = <2>; }; timer0: timer@b8001000 { compatible = "nuvoton,wpcm450-timer"; interrupts = <12 IRQ_TYPE_LEVEL_HIGH>; reg = <0xb8001000 0x1c>; clocks = <&refclk_div2>; }; ... and additionally to mark the timer clocks as critical in clk-wpcm450.c, so they don't get disabled for being "unused". > > diff --git a/drivers/clk/nuvoton/clk-wpcm450.c b/drivers/clk/nuvoton/clk-wpcm450.c > > new file mode 100644 > > index 00000000000000..9100c4b8a56483 > > --- /dev/null > > +++ b/drivers/clk/nuvoton/clk-wpcm450.c > > @@ -0,0 +1,372 @@ > > +// SPDX-License-Identifier: GPL-2.0-only > > +/* > > + * Nuvoton WPCM450 clock and reset controller driver. > > + * > > + * Copyright (C) 2022 Jonathan Neuschäfer <j.neuschaefer@gmx.net> > > + */ > > + > > +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt > > Isn't KBUILD_MODNAME an option already for dynamic debug? Indeed, it's the +m option. My motivation for setting pr_fmt in the first place should become obsolete with the move towards a platform driver anyway, because then I can use dev_err() etc. I'll remove the #define. > > > + > > +#include <linux/bitfield.h> > > +#include <linux/clk-provider.h> > > +#include <linux/io.h> > > +#include <linux/kernel.h> > > +#include <linux/module.h> > > +#include <linux/of.h> > > +#include <linux/of_address.h> > > +#include <linux/reset-controller.h> > > +#include <linux/reset/reset-simple.h> > > +#include <linux/slab.h> > > + > [...] > > + > > +static const struct clk_parent_data default_parents[] = { > > + { .name = "pll0" }, > > + { .name = "pll1" }, > > + { .name = "ref" }, > > +}; > > + > > +static const struct clk_parent_data huart_parents[] = { > > + { .fw_name = "ref" }, > > + { .name = "refdiv2" }, > > Please remove all .name elements and use indexes or direct pointers. Will do. What I'm not yet sure about, is which of these is better: 1. Having two kinds of indexes, 1. for internal use in the driver, identifying all clocks, 2. public as part of the devicetree binding ABI (defined in include/dt-bindings/clock/nuvoton,wpcm450-clk.h) 2. Unifying the two and giving every clock a public index 3. Using the same number space, but only providing public definitions (in the binding) for clocks that can be used outside the clock controller. Option 3 sounds fairly reasonable. > > +static const struct wpcm450_clken_data clken_data[] = { > > + { "fiu", { .name = "ahb3" }, WPCM450_CLK_FIU, 0 }, > > This actually is { .index = 0, .name = "ahb3" } and that is a bad > combination. struct clk_parent_data should only have .name as a fallback > when there's an old binding out there that doesn't have the 'clocks' > property for the clk provider node. There shouldn't be any .name > property because this is new code and a new binding. I'll try switching to .index or .hw instead for the references to internal clocks. [...] > > +/* > > + * NOTE: Error handling is very rudimentary here. If the clock driver initial- > > + * ization fails, the system is probably in bigger trouble than what is caused > > Don't break words across lines with hyphens. Good point. (Due to the switch to a platform driver, this comment will probably become obsolete anyway.) > > + * by a few leaked resources. > > + */ > > + > > +static void __init wpcm450_clk_init(struct device_node *np) > > +{ > > + struct clk_hw_onecell_data *clk_data; > > + static struct clk_hw **hws; > > + static struct clk_hw *hw; > > + void __iomem *clk_base; > > + int i, ret; > > + struct reset_simple_data *reset; > > + > > + clk_base = of_iomap(np, 0); > > + if (!clk_base) { > > + pr_err("%pOFP: failed to map registers\n", np); > > + of_node_put(np); > > + return; > > + } > > + of_node_put(np); > > The 'np' is used later when registering PLLs. You can only put the node > after it's no longer used. Also, you never got the node with > of_node_get(), so putting it here actually causes an underflow on the > refcount. Just remove all the get/puts instead. That simplifies it, thanks for the hint! > > + > > + clk_data = kzalloc(struct_size(clk_data, hws, WPCM450_NUM_CLKS), GFP_KERNEL); > > + if (!clk_data) > > + return; > > + > > + clk_data->num = WPCM450_NUM_CLKS; > [...] > > + /* Reset controller */ > > + reset = kzalloc(sizeof(*reset), GFP_KERNEL); > > + if (!reset) > > + return; > > + reset->rcdev.owner = THIS_MODULE; > > + reset->rcdev.nr_resets = WPCM450_NUM_RESETS; > > + reset->rcdev.ops = &reset_simple_ops; > > + reset->rcdev.of_node = np; > > + reset->membase = clk_base + REG_IPSRST; > > + ret = reset_controller_register(&reset->rcdev); > > + if (ret) > > + pr_err("Failed to register reset controller: %pe\n", ERR_PTR(ret)); > > It would be nicer to register this device as an auxiliary device with a > single API call and then have all the resets exist in that file > instead of this file. The driver would be put in drivers/reset/ as well. Not sure I'd move ten lines to a whole new file, but moving them to a separate function definitely makes sense, I'll do that. > > > + > > + of_node_put(np); > > Drop this of_node_put() Ok. Thanks for your detailed review! I'll send the next revision after testing my changes on the relevant hardware (which I currently don't have with me). -jn
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index 14fa8d4ecc1fbe..cdeb2ecf3a8e99 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -107,7 +107,7 @@ endif obj-y += mstar/ obj-y += mvebu/ obj-$(CONFIG_ARCH_MXS) += mxs/ -obj-$(CONFIG_ARCH_MA35) += nuvoton/ +obj-y += nuvoton/ obj-$(CONFIG_COMMON_CLK_NXP) += nxp/ obj-$(CONFIG_COMMON_CLK_PISTACHIO) += pistachio/ obj-$(CONFIG_COMMON_CLK_PXA) += pxa/ diff --git a/drivers/clk/nuvoton/Kconfig b/drivers/clk/nuvoton/Kconfig index fe4b7f62f46704..908881654b2e91 100644 --- a/drivers/clk/nuvoton/Kconfig +++ b/drivers/clk/nuvoton/Kconfig @@ -3,7 +3,7 @@ config COMMON_CLK_NUVOTON bool "Nuvoton clock controller common support" - depends on ARCH_MA35 || COMPILE_TEST + depends on ARCH_MA35 || ARCH_NPCM || COMPILE_TEST default y help Say y here to enable common clock controller for Nuvoton platforms. @@ -16,4 +16,12 @@ config CLK_MA35D1 help Build the clock controller driver for MA35D1 SoC. +config CLK_WPCM450 + bool "Nuvoton WPCM450 clock/reset controller support" + default y + select RESET_CONTROLLER + select RESET_SIMPLE + help + Build the clock and reset controller driver for the WPCM450 SoC. + endif diff --git a/drivers/clk/nuvoton/Makefile b/drivers/clk/nuvoton/Makefile index c3c59dd9f2aaab..b130f0d3889ca0 100644 --- a/drivers/clk/nuvoton/Makefile +++ b/drivers/clk/nuvoton/Makefile @@ -2,3 +2,4 @@ obj-$(CONFIG_CLK_MA35D1) += clk-ma35d1.o obj-$(CONFIG_CLK_MA35D1) += clk-ma35d1-divider.o obj-$(CONFIG_CLK_MA35D1) += clk-ma35d1-pll.o +obj-$(CONFIG_CLK_WPCM450) += clk-wpcm450.o diff --git a/drivers/clk/nuvoton/clk-wpcm450.c b/drivers/clk/nuvoton/clk-wpcm450.c new file mode 100644 index 00000000000000..9100c4b8a56483 --- /dev/null +++ b/drivers/clk/nuvoton/clk-wpcm450.c @@ -0,0 +1,372 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Nuvoton WPCM450 clock and reset controller driver. + * + * Copyright (C) 2022 Jonathan Neuschäfer <j.neuschaefer@gmx.net> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/bitfield.h> +#include <linux/clk-provider.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/reset-controller.h> +#include <linux/reset/reset-simple.h> +#include <linux/slab.h> + +#include <dt-bindings/clock/nuvoton,wpcm450-clk.h> + +struct wpcm450_clk_pll { + struct clk_hw hw; + void __iomem *pllcon; + u8 flags; +}; + +#define to_wpcm450_clk_pll(_hw) container_of(_hw, struct wpcm450_clk_pll, hw) + +#define PLLCON_FBDV GENMASK(24, 16) +#define PLLCON_PRST BIT(13) +#define PLLCON_PWDEN BIT(12) +#define PLLCON_OTDV GENMASK(10, 8) +#define PLLCON_INDV GENMASK(5, 0) + +static unsigned long wpcm450_clk_pll_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct wpcm450_clk_pll *pll = to_wpcm450_clk_pll(hw); + unsigned long fbdv, indv, otdv; + u64 rate; + u32 pllcon; + + if (parent_rate == 0) + return 0; + + pllcon = readl_relaxed(pll->pllcon); + + indv = FIELD_GET(PLLCON_INDV, pllcon) + 1; + fbdv = FIELD_GET(PLLCON_FBDV, pllcon) + 1; + otdv = FIELD_GET(PLLCON_OTDV, pllcon) + 1; + + rate = (u64)parent_rate * fbdv; + do_div(rate, indv * otdv); + + return rate; +} + +static int wpcm450_clk_pll_is_enabled(struct clk_hw *hw) +{ + struct wpcm450_clk_pll *pll = to_wpcm450_clk_pll(hw); + u32 pllcon; + + pllcon = readl_relaxed(pll->pllcon); + + return !(pllcon & PLLCON_PRST); +} + +static void wpcm450_clk_pll_disable(struct clk_hw *hw) +{ + struct wpcm450_clk_pll *pll = to_wpcm450_clk_pll(hw); + u32 pllcon; + + pllcon = readl_relaxed(pll->pllcon); + pllcon |= PLLCON_PRST | PLLCON_PWDEN; + writel(pllcon, pll->pllcon); +} + +static const struct clk_ops wpcm450_clk_pll_ops = { + .recalc_rate = wpcm450_clk_pll_recalc_rate, + .is_enabled = wpcm450_clk_pll_is_enabled, + .disable = wpcm450_clk_pll_disable +}; + +static struct clk_hw * +wpcm450_clk_register_pll(struct device_node *np, void __iomem *pllcon, const char *name, + const struct clk_parent_data *parent, unsigned long flags) +{ + struct wpcm450_clk_pll *pll; + struct clk_init_data init = {}; + int ret; + + pll = kzalloc(sizeof(*pll), GFP_KERNEL); + if (!pll) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &wpcm450_clk_pll_ops; + init.parent_data = parent; + init.num_parents = 1; + init.flags = flags; + + pll->pllcon = pllcon; + pll->hw.init = &init; + + ret = of_clk_hw_register(np, &pll->hw); + if (ret) { + kfree(pll); + return ERR_PTR(ret); + } + + return &pll->hw; +} + +#define REG_CLKEN 0x00 +#define REG_CLKSEL 0x04 +#define REG_CLKDIV 0x08 +#define REG_PLLCON0 0x0c +#define REG_PLLCON1 0x10 +#define REG_PMCON 0x14 +#define REG_IRQWAKECON 0x18 +#define REG_IRQWAKEFLAG 0x1c +#define REG_IPSRST 0x20 + +struct wpcm450_pll_data { + const char *name; + struct clk_parent_data parent; + unsigned int reg; + unsigned long flags; +}; + +static const struct wpcm450_pll_data pll_data[] = { + { "pll0", { .fw_name = "ref" }, REG_PLLCON0, 0 }, + { "pll1", { .fw_name = "ref" }, REG_PLLCON1, 0 }, +}; + +struct wpcm450_clksel_data { + const char *name; + const struct clk_parent_data *parents; + unsigned int num_parents; + const u32 *table; + int shift; + int width; + int index; + unsigned long flags; +}; + +static const u32 parent_table[] = { 0, 1, 2 }; + +static const struct clk_parent_data default_parents[] = { + { .name = "pll0" }, + { .name = "pll1" }, + { .name = "ref" }, +}; + +static const struct clk_parent_data huart_parents[] = { + { .fw_name = "ref" }, + { .name = "refdiv2" }, +}; + +static const struct wpcm450_clksel_data clksel_data[] = { + { "cpusel", default_parents, ARRAY_SIZE(default_parents), + parent_table, 0, 2, -1, CLK_IS_CRITICAL }, + { "clkout", default_parents, ARRAY_SIZE(default_parents), + parent_table, 2, 2, -1, 0 }, + { "usbphy", default_parents, ARRAY_SIZE(default_parents), + parent_table, 6, 2, -1, 0 }, + { "uartsel", default_parents, ARRAY_SIZE(default_parents), + parent_table, 8, 2, WPCM450_CLK_USBPHY, 0 }, + { "huartsel", huart_parents, ARRAY_SIZE(huart_parents), + parent_table, 10, 1, -1, 0 }, +}; + +static const struct clk_div_table div_fixed2[] = { + { .val = 0, .div = 2 }, + { } +}; + +struct wpcm450_clkdiv_data { + const char *name; + struct clk_parent_data parent; + int div_flags; + const struct clk_div_table *table; + int shift; + int width; + unsigned long flags; +}; + +static struct wpcm450_clkdiv_data clkdiv_data_early[] = { + { "refdiv2", { .name = "ref" }, 0, div_fixed2, 0, 0 }, +}; + +static const struct wpcm450_clkdiv_data clkdiv_data[] = { + { "cpu", { .name = "cpusel" }, 0, div_fixed2, 0, 0, CLK_IS_CRITICAL }, + { "adcdiv", { .name = "ref" }, CLK_DIVIDER_POWER_OF_TWO, NULL, 28, 2, 0 }, + { "apb", { .name = "ahb" }, CLK_DIVIDER_POWER_OF_TWO, NULL, 26, 2, 0 }, + { "ahb", { .name = "cpu" }, CLK_DIVIDER_POWER_OF_TWO, NULL, 24, 2, 0 }, + { "uart", { .name = "uartsel" }, 0, NULL, 16, 4, 0 }, + { "ahb3", { .name = "ahb" }, CLK_DIVIDER_POWER_OF_TWO, NULL, 8, 2, 0 }, +}; + +struct wpcm450_clken_data { + const char *name; + struct clk_parent_data parent; + int bitnum; + unsigned long flags; +}; + +static const struct wpcm450_clken_data clken_data[] = { + { "fiu", { .name = "ahb3" }, WPCM450_CLK_FIU, 0 }, + { "xbus", { .name = "ahb3" }, WPCM450_CLK_XBUS, 0 }, + { "kcs", { .name = "apb" }, WPCM450_CLK_KCS, 0 }, + { "shm", { .name = "ahb3" }, WPCM450_CLK_SHM, 0 }, + { "usb1", { .name = "ahb" }, WPCM450_CLK_USB1, 0 }, + { "emc0", { .name = "ahb" }, WPCM450_CLK_EMC0, 0 }, + { "emc1", { .name = "ahb" }, WPCM450_CLK_EMC1, 0 }, + { "usb0", { .name = "ahb" }, WPCM450_CLK_USB0, 0 }, + { "peci", { .name = "apb" }, WPCM450_CLK_PECI, 0 }, + { "aes", { .name = "apb" }, WPCM450_CLK_AES, 0 }, + { "uart0", { .name = "uart" }, WPCM450_CLK_UART0, 0 }, + { "uart1", { .name = "uart" }, WPCM450_CLK_UART1, 0 }, + { "smb2", { .name = "apb" }, WPCM450_CLK_SMB2, 0 }, + { "smb3", { .name = "apb" }, WPCM450_CLK_SMB3, 0 }, + { "smb4", { .name = "apb" }, WPCM450_CLK_SMB4, 0 }, + { "smb5", { .name = "apb" }, WPCM450_CLK_SMB5, 0 }, + { "huart", { .name = "huartsel" }, WPCM450_CLK_HUART, 0 }, + { "pwm", { .name = "apb" }, WPCM450_CLK_PWM, 0 }, + { "timer0", { .name = "refdiv2" }, WPCM450_CLK_TIMER0, 0 }, + { "timer1", { .name = "refdiv2" }, WPCM450_CLK_TIMER1, 0 }, + { "timer2", { .name = "refdiv2" }, WPCM450_CLK_TIMER2, 0 }, + { "timer3", { .name = "refdiv2" }, WPCM450_CLK_TIMER3, 0 }, + { "timer4", { .name = "refdiv2" }, WPCM450_CLK_TIMER4, 0 }, + { "mft0", { .name = "apb" }, WPCM450_CLK_MFT0, 0 }, + { "mft1", { .name = "apb" }, WPCM450_CLK_MFT1, 0 }, + { "wdt", { .name = "refdiv2" }, WPCM450_CLK_WDT, 0 }, + { "adc", { .name = "adcdiv" }, WPCM450_CLK_ADC, 0 }, + { "sdio", { .name = "ahb" }, WPCM450_CLK_SDIO, 0 }, + { "sspi", { .name = "apb" }, WPCM450_CLK_SSPI, 0 }, + { "smb0", { .name = "apb" }, WPCM450_CLK_SMB0, 0 }, + { "smb1", { .name = "apb" }, WPCM450_CLK_SMB1, 0 }, +}; + +static DEFINE_SPINLOCK(wpcm450_clk_lock); + +/* + * NOTE: Error handling is very rudimentary here. If the clock driver initial- + * ization fails, the system is probably in bigger trouble than what is caused + * by a few leaked resources. + */ + +static void __init wpcm450_clk_init(struct device_node *np) +{ + struct clk_hw_onecell_data *clk_data; + static struct clk_hw **hws; + static struct clk_hw *hw; + void __iomem *clk_base; + int i, ret; + struct reset_simple_data *reset; + + clk_base = of_iomap(np, 0); + if (!clk_base) { + pr_err("%pOFP: failed to map registers\n", np); + of_node_put(np); + return; + } + of_node_put(np); + + clk_data = kzalloc(struct_size(clk_data, hws, WPCM450_NUM_CLKS), GFP_KERNEL); + if (!clk_data) + return; + + clk_data->num = WPCM450_NUM_CLKS; + hws = clk_data->hws; + + for (i = 0; i < WPCM450_NUM_CLKS; i++) + hws[i] = ERR_PTR(-ENOENT); + + /* PLLs */ + for (i = 0; i < ARRAY_SIZE(pll_data); i++) { + const struct wpcm450_pll_data *data = &pll_data[i]; + + hw = wpcm450_clk_register_pll(np, clk_base + data->reg, data->name, + &data->parent, data->flags); + if (IS_ERR(hw)) { + pr_info("Failed to register PLL: %pe\n", hw); + return; + } + } + + /* Early divisors (REF/2) */ + for (i = 0; i < ARRAY_SIZE(clkdiv_data_early); i++) { + const struct wpcm450_clkdiv_data *data = &clkdiv_data_early[i]; + + hw = clk_hw_register_divider_table_parent_data(NULL, data->name, &data->parent, + data->flags, clk_base + REG_CLKDIV, + data->shift, data->width, + data->div_flags, data->table, + &wpcm450_clk_lock); + if (IS_ERR(hw)) { + pr_err("Failed to register div table: %pe\n", hw); + return; + } + } + + /* Selects/muxes */ + for (i = 0; i < ARRAY_SIZE(clksel_data); i++) { + const struct wpcm450_clksel_data *data = &clksel_data[i]; + + hw = clk_hw_register_mux_parent_data(NULL, data->name, data->parents, + data->num_parents, data->flags, + clk_base + REG_CLKSEL, data->shift, + data->width, 0, + &wpcm450_clk_lock); + if (IS_ERR(hw)) { + pr_err("Failed to register mux: %pe\n", hw); + return; + } + if (data->index >= 0) + clk_data->hws[data->index] = hw; + } + + /* Divisors */ + for (i = 0; i < ARRAY_SIZE(clkdiv_data); i++) { + const struct wpcm450_clkdiv_data *data = &clkdiv_data[i]; + + hw = clk_hw_register_divider_table_parent_data(NULL, data->name, &data->parent, + data->flags, clk_base + REG_CLKDIV, + data->shift, data->width, + data->div_flags, data->table, + &wpcm450_clk_lock); + if (IS_ERR(hw)) { + pr_err("Failed to register divider: %pe\n", hw); + return; + } + } + + /* Enables/gates */ + for (i = 0; i < ARRAY_SIZE(clken_data); i++) { + const struct wpcm450_clken_data *data = &clken_data[i]; + + hw = clk_hw_register_gate_parent_data(NULL, data->name, &data->parent, data->flags, + clk_base + REG_CLKEN, data->bitnum, + data->flags, &wpcm450_clk_lock); + if (IS_ERR(hw)) { + pr_err("Failed to register gate: %pe\n", hw); + return; + } + clk_data->hws[data->bitnum] = hw; + } + + ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, clk_data); + if (ret) + pr_err("Failed to add DT provider: %pe\n", ERR_PTR(ret)); + + /* Reset controller */ + reset = kzalloc(sizeof(*reset), GFP_KERNEL); + if (!reset) + return; + reset->rcdev.owner = THIS_MODULE; + reset->rcdev.nr_resets = WPCM450_NUM_RESETS; + reset->rcdev.ops = &reset_simple_ops; + reset->rcdev.of_node = np; + reset->membase = clk_base + REG_IPSRST; + ret = reset_controller_register(&reset->rcdev); + if (ret) + pr_err("Failed to register reset controller: %pe\n", ERR_PTR(ret)); + + of_node_put(np); +} + +CLK_OF_DECLARE(wpcm450_clk_init, "nuvoton,wpcm450-clk", wpcm450_clk_init);
This driver implements the following features w.r.t. the clock and reset controller in the WPCM450 SoC: - It calculates the rates for all clocks managed by the clock controller - It leaves the clock tree mostly unchanged, except that it enables/ disables clock gates based on usage. - It exposes the reset lines managed by the controller using the Generic Reset Controller subsystem NOTE: If the driver and the corresponding devicetree node are present, the driver will disable "unused" clocks. This is problem until the clock relations are properly declared in the devicetree (in a later patch). Until then, the clk_ignore_unused kernel parameter can be used as a workaround. Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Reviewed-by: Joel Stanley <joel@jms.id.au> --- I have considered converting this driver to a platform driver instead of using CLK_OF_DECLARE, because platform drivers are generally the way forward. However, the timer-npcm7xx driver used on the same platform requires is initialized with TIMER_OF_DECLARE and thus requires the clocks to be available earlier than a platform driver can provide them. v11: - no changes v10: - select RESET_{CONTROLLER,SIMPLE} from CLK_WPCM450 instead of messing with the 'default' statement v9: - Apply comments made by Stephen Boyd - Move to drivers/clk/nuvoton/ directory - Update SPDX license identifier from GPL-2.0 to GPL-2.0-only - Rename clk_np variable to np - Use of_clk_hw_register - Refer to clock parents by .fw_name v8: - https://lore.kernel.org/lkml/20230428190226.1304326-3-j.neuschaefer@gmx.net/ - Use %pe format specifier throughout the driver, as suggested by Philipp Zabel - Add Joel's R-b v7: - https://lore.kernel.org/lkml/20230422220240.322572-3-j.neuschaefer@gmx.net/ - Simplify error handling by not deallocating resources v6: - Enable RESET_SIMPLE based on ARCH_WPCM450, not ARCH_NPCM, as suggested by Tomer Maimon v5: - https://lore.kernel.org/lkml/20221104161850.2889894-6-j.neuschaefer@gmx.net/ - Switch to using clk_parent_data v4: - Fix reset controller initialization v3: - Change reference clock name from "refclk" to "ref" - Remove unused variable in return path of wpcm450_clk_register_pll - Remove unused divisor tables v2: - no changes --- drivers/clk/Makefile | 2 +- drivers/clk/nuvoton/Kconfig | 10 +- drivers/clk/nuvoton/Makefile | 1 + drivers/clk/nuvoton/clk-wpcm450.c | 372 ++++++++++++++++++++++++++++++++++++++ 4 files changed, 383 insertions(+), 2 deletions(-) -- 2.43.0