clk: at91: add generated clock driver

Message ID	1434547409-12232-1-git-send-email-nicolas.ferre@atmel.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org> From: Nicolas Ferre <nicolas.ferre@atmel.com> To: Boris BREZILLON <boris.brezillon@free-electrons.com>, <linux-arm-kernel@lists.infradead.org> Subject: [PATCH] clk: at91: add generated clock driver Date: Wed, 17 Jun 2015 15:23:29 +0200 Message-ID: <1434547409-12232-1-git-send-email-nicolas.ferre@atmel.com> MIME-Version: 1.0 Cc: mturquette@baylibre.com, Nicolas Ferre <nicolas.ferre@atmel.com>, linux-kernel@vger.kernel.org, Josh Wu <josh.wu@atmel.com>, Ludovic Desroches <ludovic.desroches@atmel.com>, Alexandre Belloni <alexandre.belloni@free-electrons.com> Precedence: list Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" <linux-arm-kernel-bounces@lists.infradead.org> Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org

diff --git a/Documentation/devicetree/bindings/clock/at91-clock.txt b/Documentation/devicetree/bindings/clock/at91-clock.txt index 5ba6450693b9..5e737d2cd05d 100644 --- a/Documentation/devicetree/bindings/clock/at91-clock.txt +++ b/Documentation/devicetree/bindings/clock/at91-clock.txt @@ -77,6 +77,9 @@ Required properties: "atmel,sama5d4-clk-h32mx": at91 h32mx clock + "atmel,sama5d2-clk-generated": + at91 generated clock + Required properties for SCKC node: - reg : defines the IO memory reserved for the SCKC. - #size-cells : shall be 0 (reg is used to encode clk id). @@ -461,3 +464,35 @@ For example: compatible = "atmel,sama5d4-clk-h32mx"; clocks = <&mck>; }; + +Required properties for generated clocks: +- #size-cells : shall be 0 (reg is used to encode clk id). +- #address-cells : shall be 1 (reg is used to encode clk id). +- clocks : shall be the generated clock source phandles. + e.g. clocks = <&clk32k>, <&main>, <&plladiv>, <&utmi>, <&mck>; +- name: device tree node describing a specific generated clock. + * #clock-cells : from common clock binding; shall be set to 0. + * reg: peripheral id. See Atmel's datasheets to get a full + list of peripheral ids. + * atmel,clk-output-range : minimum and maximum clock frequency + (two u32 fields). + +For example: + gck { + compatible = "atmel,sama5d2-clk-generated"; + #address-cells = <1>; + #size-cells = <0>; + clocks = <&clk32k>, <&main>, <&plladiv>, <&utmi>, <&mck>; + + tcb0_gclk: tcb0_gclk { + #clock-cells = <0>; + reg = <35>; + atmel,clk-output-range = <0 83000000>; + }; + + pwm_gclk: pwm_gclk { + #clock-cells = <0>; + reg = <38>; + atmel,clk-output-range = <0 83000000>; + }; + }; diff --git a/arch/arm/mach-at91/Kconfig b/arch/arm/mach-at91/Kconfig index fd95f34945f4..43ec794d1057 100644 --- a/arch/arm/mach-at91/Kconfig +++ b/arch/arm/mach-at91/Kconfig @@ -90,6 +90,9 @@ config HAVE_AT91_SMD config HAVE_AT91_H32MX bool +config HAVE_AT91_GENERATED + bool + config SOC_SAM_V4_V5 bool diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile index 89a48a7bd5df..867e5d1b295e 100644 --- a/drivers/clk/at91/Makefile +++ b/drivers/clk/at91/Makefile @@ -10,3 +10,4 @@ obj-$(CONFIG_HAVE_AT91_UTMI) += clk-utmi.o obj-$(CONFIG_HAVE_AT91_USB_CLK) += clk-usb.o obj-$(CONFIG_HAVE_AT91_SMD) += clk-smd.o obj-$(CONFIG_HAVE_AT91_H32MX) += clk-h32mx.o +obj-$(CONFIG_HAVE_AT91_GENERATED) += clk-generated.o diff --git a/drivers/clk/at91/clk-generated.c b/drivers/clk/at91/clk-generated.c new file mode 100644 index 000000000000..4db46b0f07b4 --- /dev/null +++ b/drivers/clk/at91/clk-generated.c @@ -0,0 +1,329 @@ +/* + * Copyright (C) 2015 Atmel Corporation, + * Nicolas Ferre <nicolas.ferre@atmel.com> + * + * Based on clk-programmable & clk-peripheral drivers by Boris BREZILLON. + * + * 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. + * + */ + +#include <linux/clk-provider.h> +#include <linux/clkdev.h> +#include <linux/clk/at91_pmc.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/io.h> + +#include "pmc.h" + +#define PERIPHERAL_MAX 64 + +#define PERIPHERAL_ID_MIN 2 + +#define GENERATED_SOURCE_MAX 6 +#define GENERATED_MAX_DIV 255 + +struct clk_generated { + struct clk_hw hw; + struct at91_pmc *pmc; + struct clk_range range; + u32 id; + u32 gckdiv; + u8 parent_id; +}; + +#define to_clk_generated(hw) \ + container_of(hw, struct clk_generated, hw) + +static int clk_generated_enable(struct clk_hw *hw) +{ + struct clk_generated *gck = to_clk_generated(hw); + struct at91_pmc *pmc = gck->pmc; + u32 tmp; + + if (gck->id < PERIPHERAL_ID_MIN) + return 0; + + pr_debug("GCLK: %s, gckdiv = %d, parent id = %d\n", + __FUNCTION__, gck->gckdiv, gck->parent_id); + + pmc_lock(pmc); + pmc_write(pmc, AT91_PMC_PCR, (gck->id & AT91_PMC_PCR_PID_MASK)); + tmp = pmc_read(pmc, AT91_PMC_PCR) & + ~(AT91_PMC_PCR_GCKDIV_MASK | AT91_PMC_PCR_GCKCSS_MASK); + pmc_write(pmc, AT91_PMC_PCR, tmp | AT91_PMC_PCR_GCKCSS(gck->parent_id) + | AT91_PMC_PCR_CMD + | AT91_PMC_PCR_GCKDIV(gck->gckdiv) + | AT91_PMC_PCR_GCKEN); + pmc_unlock(pmc); + return 0; +} + +static void clk_generated_disable(struct clk_hw *hw) +{ + struct clk_generated *gck = to_clk_generated(hw); + struct at91_pmc *pmc = gck->pmc; + u32 tmp; + + if (gck->id < PERIPHERAL_ID_MIN) + return; + + pmc_lock(pmc); + pmc_write(pmc, AT91_PMC_PCR, (gck->id & AT91_PMC_PCR_PID_MASK)); + tmp = pmc_read(pmc, AT91_PMC_PCR) & ~AT91_PMC_PCR_GCKEN; + pmc_write(pmc, AT91_PMC_PCR, tmp | AT91_PMC_PCR_CMD); + pmc_unlock(pmc); +} + +static int clk_generated_is_enabled(struct clk_hw *hw) +{ + struct clk_generated *gck = to_clk_generated(hw); + struct at91_pmc *pmc = gck->pmc; + int ret; + + if (gck->id < PERIPHERAL_ID_MIN) + return 1; + + pmc_lock(pmc); + pmc_write(pmc, AT91_PMC_PCR, (gck->id & AT91_PMC_PCR_PID_MASK)); + ret = !!(pmc_read(pmc, AT91_PMC_PCR) & AT91_PMC_PCR_GCKEN); + pmc_unlock(pmc); + + return ret; +} + +static unsigned long +clk_generated_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_generated *gck = to_clk_generated(hw); + + if (gck->id < PERIPHERAL_ID_MIN) + return parent_rate; + + return DIV_ROUND_CLOSEST(parent_rate, gck->gckdiv + 1); +} + +static long clk_generated_determine_rate(struct clk_hw *hw, + unsigned long rate, + unsigned long *best_parent_rate, + struct clk_hw **best_parent_hw) +{ + struct clk_generated *gck = to_clk_generated(hw); + struct clk *parent = NULL; + long best_rate = -EINVAL; + unsigned long tmp_rate; + int best_diff = -1; + int tmp_diff; + int i; + + for (i = 0; i < __clk_get_num_parents(hw->clk); i++) { + u32 div; + unsigned long parent_rate; + + parent = clk_get_parent_by_index(hw->clk, i); + if (!parent) + continue; + + parent_rate = __clk_get_rate(parent); + if (!parent_rate + || DIV_ROUND_CLOSEST(parent_rate, GENERATED_MAX_DIV + 1) + > gck->range.max) + continue; + + for (div = 1; div < GENERATED_MAX_DIV + 2; div++) { + + tmp_rate = DIV_ROUND_CLOSEST(parent_rate, div); + tmp_diff = abs(rate - tmp_rate); + + if (best_diff < 0 || best_diff > tmp_diff) { + best_rate = tmp_rate; + best_diff = tmp_diff; + *best_parent_rate = parent_rate; + *best_parent_hw = __clk_get_hw(parent); + } + + if (!best_diff || tmp_rate < rate) + break; + } + + if (!best_diff) + break; + } + + pr_debug("GCLK: %s, best_rate = %ld, parent clk: %s @ %ld\n" , + __FUNCTION__ , best_rate, + __clk_get_name((*best_parent_hw)->clk), *best_parent_rate); + + return best_rate; +} + +/* No modification of hardware as we have the flag CLK_SET_PARENT_GATE set */ +static int clk_generated_set_parent(struct clk_hw *hw, u8 index) +{ + struct clk_generated *gck = to_clk_generated(hw); + + if (index >= __clk_get_num_parents(hw->clk)) + return -EINVAL; + + gck->parent_id = index; + return 0; +} + +static u8 clk_generated_get_parent(struct clk_hw *hw) +{ + struct clk_generated *gck = to_clk_generated(hw); + + return gck->parent_id; +} + +/* No modification of hardware as we have the flag CLK_SET_RATE_GATE set */ +static int clk_generated_set_rate(struct clk_hw *hw, + unsigned long rate, + unsigned long parent_rate) +{ + struct clk_generated *gck = to_clk_generated(hw); + u32 div; + + if (!rate) + return -EINVAL; + + if (gck->id < PERIPHERAL_ID_MIN || !gck->range.max) { + if (parent_rate == rate) { + gck->gckdiv = 0; + return 0; + } else { + return -EINVAL; + } + } + + if (rate > gck->range.max) + return -EINVAL; + + div = DIV_ROUND_CLOSEST(parent_rate, rate); + if (div > GENERATED_MAX_DIV + 1 || !div) + return -EINVAL; + + gck->gckdiv = div - 1; + return 0; +} + +static const struct clk_ops generated_ops = { + .enable = clk_generated_enable, + .disable = clk_generated_disable, + .is_enabled = clk_generated_is_enabled, + .recalc_rate = clk_generated_recalc_rate, + .determine_rate = clk_generated_determine_rate, + .get_parent = clk_generated_get_parent, + .set_parent = clk_generated_set_parent, + .set_rate = clk_generated_set_rate, +}; + +/** + * clk_generated_startup - Initialize a given clock to its default parent and + * divisor parameter. + * + * @gck: Generated clock to set the startup parameters for. + * + * Take parameters from the hardware and update local clock configuration + * accordingly. + */ +static void clk_generated_startup(struct clk_generated *gck) +{ + struct at91_pmc *pmc = gck->pmc; + u32 tmp; + + pmc_lock(pmc); + pmc_write(pmc, AT91_PMC_PCR, (gck->id & AT91_PMC_PCR_PID_MASK)); + tmp = pmc_read(pmc, AT91_PMC_PCR); + pmc_unlock(pmc); + + gck->parent_id = (tmp & AT91_PMC_PCR_GCKCSS_MASK) >> AT91_PMC_PCR_GCKCSS_OFFSET; + gck->gckdiv = (tmp & AT91_PMC_PCR_GCKDIV_MASK) >> AT91_PMC_PCR_GCKDIV_OFFSET; +} + +static struct clk * __init +at91_clk_register_generated(struct at91_pmc *pmc, const char *name, + const char **parent_names, u8 num_parents, + u8 id, const struct clk_range *range) +{ + struct clk_generated *gck; + struct clk *clk = NULL; + struct clk_init_data init; + + gck = kzalloc(sizeof(*gck), GFP_KERNEL); + if (!gck) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &generated_ops; + init.parent_names = parent_names; + init.num_parents = num_parents; + init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE; + + gck->id = id; + gck->hw.init = &init; + gck->pmc = pmc; + gck->range = *range; + + clk = clk_register(NULL, &gck->hw); + if (IS_ERR(clk)) + kfree(gck); + else + clk_generated_startup(gck); + + return clk; +} + +void __init of_sama5d2_clk_generated_setup(struct device_node *np, + struct at91_pmc *pmc) +{ + int i; + int num; + u32 id; + const char *name; + struct clk *clk; + int num_parents; + const char *parent_names[GENERATED_SOURCE_MAX]; + struct device_node *gcknp; + struct clk_range range = CLK_RANGE(0, 0); + + num_parents = of_count_phandle_with_args(np, "clocks", "#clock-cells"); + if (num_parents <= 0 || num_parents > GENERATED_SOURCE_MAX) + return; + + for (i = 0; i < num_parents; ++i) { + parent_names[i] = of_clk_get_parent_name(np, i); + if (!parent_names[i]) + return; + } + + num = of_get_child_count(np); + if (!num || num > PERIPHERAL_MAX) + return; + + for_each_child_of_node(np, gcknp) { + if (of_property_read_u32(gcknp, "reg", &id)) + continue; + + if (id >= PERIPHERAL_MAX) + continue; + + if (of_property_read_string(np, "clock-output-names", &name)) + name = gcknp->name; + + of_at91_get_clk_range(gcknp, "atmel,clk-output-range", + &range); + + clk = at91_clk_register_generated(pmc, name, parent_names, + num_parents, id, &range); + if (IS_ERR(clk)) + continue; + + of_clk_add_provider(gcknp, of_clk_src_simple_get, clk); + } +} diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c index 39be2be82b0a..bed2ce6b3cb9 100644 --- a/drivers/clk/at91/pmc.c +++ b/drivers/clk/at91/pmc.c @@ -370,6 +370,12 @@ static const struct of_device_id pmc_clk_ids[] __initconst = { .data = of_sama5d4_clk_h32mx_setup, }, #endif +#if defined(CONFIG_HAVE_AT91_GENERATED) + { + .compatible = "atmel,sama5d2-clk-generated", + .data = of_sama5d2_clk_generated_setup, + }, +#endif { /*sentinel*/ } }; diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h index 69abb08cf146..e40623a4d7aa 100644 --- a/drivers/clk/at91/pmc.h +++ b/drivers/clk/at91/pmc.h @@ -126,4 +126,9 @@ extern void __init of_sama5d4_clk_h32mx_setup(struct device_node *np, struct at91_pmc *pmc); #endif +#if defined(CONFIG_HAVE_AT91_GENERATED) +extern void __init of_sama5d2_clk_generated_setup(struct device_node *np, + struct at91_pmc *pmc); +#endif + #endif /* __PMC_H_ */ diff --git a/include/linux/clk/at91_pmc.h b/include/linux/clk/at91_pmc.h index dfc59e2b64fb..ae61860e6892 100644 --- a/include/linux/clk/at91_pmc.h +++ b/include/linux/clk/at91_pmc.h @@ -183,10 +183,17 @@ extern void __iomem *at91_pmc_base; #define AT91_PMC_PCR 0x10c /* Peripheral Control Register [some SAM9 and SAMA5] */ #define AT91_PMC_PCR_PID_MASK 0x3f +#define AT91_PMC_PCR_GCKCSS_OFFSET 8 +#define AT91_PMC_PCR_GCKCSS_MASK (0x7 << AT91_PMC_PCR_GCKCSS_OFFSET) +#define AT91_PMC_PCR_GCKCSS(n) ((n) << AT91_PMC_PCR_GCKCSS_OFFSET) /* GCK Clock Source Selection */ #define AT91_PMC_PCR_CMD (0x1 << 12) /* Command (read=0, write=1) */ #define AT91_PMC_PCR_DIV_OFFSET 16 #define AT91_PMC_PCR_DIV_MASK (0x3 << AT91_PMC_PCR_DIV_OFFSET) #define AT91_PMC_PCR_DIV(n) ((n) << AT91_PMC_PCR_DIV_OFFSET) /* Divisor Value */ +#define AT91_PMC_PCR_GCKDIV_OFFSET 20 +#define AT91_PMC_PCR_GCKDIV_MASK (0xff << AT91_PMC_PCR_GCKDIV_OFFSET) +#define AT91_PMC_PCR_GCKDIV(n) ((n) << AT91_PMC_PCR_GCKDIV_OFFSET) /* Generated Clock Divisor Value */ #define AT91_PMC_PCR_EN (0x1 << 28) /* Enable */ +#define AT91_PMC_PCR_GCKEN (0x1 << 29) /* GCK Enable */ #endif

clk: at91: add generated clock driver

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