Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755674Ab3FGOiO (ORCPT ); Fri, 7 Jun 2013 10:38:14 -0400 Received: from 13.mo1.mail-out.ovh.net ([178.33.253.128]:51213 "EHLO mo1.mail-out.ovh.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755157Ab3FGOiL (ORCPT ); Fri, 7 Jun 2013 10:38:11 -0400 X-Greylist: delayed 20566 seconds by postgrey-1.27 at vger.kernel.org; Fri, 07 Jun 2013 10:38:11 EDT From: Boris BREZILLON To: Mike Turquette , Jean-Christophe Plagniol-Villard , Nicolas Ferre , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Grant Likely , Rob Herring Cc: Boris BREZILLON , devicetree-discuss@lists.ozlabs.org X-Ovh-Mailout: 178.32.228.1 (mo1.mail-out.ovh.net) Subject: [RFC PATCH 07/50] ARM: at91: add PMC programmable clocks Date: Fri, 7 Jun 2013 16:24:15 +0200 Message-Id: <1370615115-16979-8-git-send-email-b.brezillon@overkiz.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1370615115-16979-1-git-send-email-b.brezillon@overkiz.com> References: <1370615115-16979-1-git-send-email-b.brezillon@overkiz.com> X-Ovh-Tracer-Id: 17284533896806053036 X-Ovh-Remote: 80.245.18.66 () X-Ovh-Local: 213.186.33.20 (ns0.ovh.net) X-OVH-SPAMSTATE: OK X-OVH-SPAMSCORE: -100 X-OVH-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrfeeiiedrgedtucetufdoteggodetrfcurfhrohhfihhlvgemucfqggfjnecuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmd X-Spam-Check: DONE|U 0.5/N X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrfeeiiedrgedtucetufdoteggodetrfcurfhrohhfihhlvgemucfqggfjnecuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmd Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 11434 Lines: 447 This is the at91 programmable clocks implementation using common clk framework. A programmable clock is a clock which can be exported on a given pin to clock external devices. Each programmable clock is given an id (from 0 to 8). The number of available programmable clocks depends on the SoC you're using. Programmable clock driver only implements the clock setting (clock rate and parent setting). It must be chained to a system clock in order to enable/disable the generated clock. The PCKX pins used to output the clock signals must be assigned to the appropriate peripheral (see atmel's datasheets). Signed-off-by: Boris BREZILLON --- drivers/clk/at91/Makefile | 2 + drivers/clk/at91/clk-programmable.c | 370 +++++++++++++++++++++++++++++++++++ include/linux/clk/at91.h | 18 ++ 3 files changed, 390 insertions(+) diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile index 3e2a670..2d7c119 100644 --- a/drivers/clk/at91/Makefile +++ b/drivers/clk/at91/Makefile @@ -4,3 +4,5 @@ obj-y += clk-main.o clk-pll.o clk-plldiv.o clk-master.o obj-y += clk-system.o clk-peripheral.o + +obj-$(CONFIG_AT91_PROGRAMMABLE_CLOCKS) += clk-programmable.o diff --git a/drivers/clk/at91/clk-programmable.c b/drivers/clk/at91/clk-programmable.c new file mode 100644 index 0000000..e4b1fb0 --- /dev/null +++ b/drivers/clk/at91/clk-programmable.c @@ -0,0 +1,370 @@ +/* + * drivers/clk/at91/clk-programmable.c + * + * Copyright (C) 2013 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 +#include +#include +#include +#include +#include + +#define PROG_SOURCE_MAX 5 +#define PROG_MAX 8 + +#define to_clk_programmable(hw) container_of(hw, struct clk_programmable, hw) +struct clk_programmable { + struct clk_hw hw; + u8 id; + u8 css; + u8 pres; + u8 slckmck; + struct clk_programmable_layout *layout; +}; + +static int clk_programmable_prepare(struct clk_hw *hw) +{ + u32 tmp; + struct clk_programmable *prog = to_clk_programmable(hw); + struct clk_programmable_layout *layout = prog->layout; + tmp = prog->css | (prog->pres << layout->pres_shift); + if (layout->have_slck_mck && prog->slckmck) + tmp |= 1 << 8; + at91_pmc_write(AT91_PMC_PCKR(prog->id), tmp); + while (!(at91_pmc_read(AT91_PMC_SR) & (AT91_PMC_PCK0RDY << prog->id))) + ; + return 0; +} + +static int clk_programmable_is_prepared(struct clk_hw *hw) +{ + struct clk_programmable *prog = to_clk_programmable(hw); + return !!(at91_pmc_read(AT91_PMC_SR) & (AT91_PMC_PCK0RDY << prog->id)); +} + +static unsigned long clk_programmable_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + u32 tmp; + struct clk_programmable *prog = to_clk_programmable(hw); + struct clk_programmable_layout *layout = prog->layout; + tmp = at91_pmc_read(AT91_PMC_PCKR(prog->id)); + prog->pres = (tmp >> layout->pres_shift) & 0x7; + return parent_rate >> prog->pres; +} + +static long clk_programmable_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + unsigned long best_rate = *parent_rate; + unsigned long best_diff; + unsigned long new_diff; + unsigned long cur_rate; + int shift = shift; + + if (rate > *parent_rate) + return *parent_rate; + else + best_diff = *parent_rate - rate; + + if (!best_diff) + return best_rate; + + for (shift = 1; shift < 7; shift++) { + cur_rate = *parent_rate >> shift; + + if (cur_rate > rate) + new_diff = cur_rate - rate; + else + new_diff = rate - cur_rate; + + if (!new_diff) + return cur_rate; + + if (new_diff < best_diff) { + best_diff = new_diff; + best_rate = cur_rate; + } + + if (rate > cur_rate) + break; + + } + + return best_rate; +} + +static int clk_programmable_set_parent(struct clk_hw *hw, u8 index) +{ + struct clk_programmable *prog = to_clk_programmable(hw); + struct clk_programmable_layout *layout = prog->layout; + if (index > layout->css_mask) { + if (index == 4 && layout->have_slck_mck) { + prog->css = 0; + prog->slckmck = 1; + return 0; + } else + return -EINVAL; + } + + prog->css = index; + return 0; +} + +static u8 clk_programmable_get_parent(struct clk_hw *hw) +{ + u32 tmp; + u8 ret; + struct clk_programmable *prog = to_clk_programmable(hw); + struct clk_programmable_layout *layout = prog->layout; + tmp = at91_pmc_read(AT91_PMC_PCKR(prog->id)); + prog->css = tmp & layout->css_mask; + ret = prog->css; + if (layout->have_slck_mck) { + prog->slckmck = !!(tmp & (1 << 8)); + if (prog->slckmck && !ret) + ret = 4; + } + + return ret; +} + +static int clk_programmable_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct clk_programmable *prog = to_clk_programmable(hw); + unsigned long best_rate = parent_rate; + unsigned long best_diff; + unsigned long new_diff; + unsigned long cur_rate; + int shift = 0; + + if (rate > parent_rate) + return parent_rate; + else + best_diff = parent_rate - rate; + + if (!best_diff) { + prog->pres = shift; + return 0; + } + + for (shift = 1; shift < 7; shift++) { + cur_rate = parent_rate >> shift; + + if (cur_rate > rate) + new_diff = cur_rate - rate; + else + new_diff = rate - cur_rate; + + if (!new_diff) + break; + + if (new_diff < best_diff) { + best_diff = new_diff; + best_rate = cur_rate; + } + + if (rate > cur_rate) + break; + + } + + prog->pres = shift; + return 0; +} + +static const struct clk_ops programmable_ops = { + .prepare = clk_programmable_prepare, + .is_prepared = clk_programmable_is_prepared, + .recalc_rate = clk_programmable_recalc_rate, + .round_rate = clk_programmable_round_rate, + .get_parent = clk_programmable_get_parent, + .set_parent = clk_programmable_set_parent, + .set_rate = clk_programmable_set_rate, +}; + +struct clk * __init +at91_clk_register_programmable(const char *name, const char **parent_names, + u8 num_parents, u8 id, + struct clk_programmable_layout *layout) +{ + struct clk_programmable *prog; + struct clk *clk = NULL; + struct clk_init_data init; + + id &= 7; + + prog = kzalloc(sizeof(*prog), GFP_KERNEL); + if (!prog) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &programmable_ops; + init.parent_names = parent_names; + init.num_parents = num_parents; + init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE; + + prog->id = id; + prog->layout = layout; + prog->hw.init = &init; + + clk = clk_register(NULL, &prog->hw); + + if (IS_ERR(clk)) + kfree(prog); + + return clk; +} + +struct clk_programmable_layout at91rm9200_programmable_layout = { + .pres_shift = 2, + .css_mask = 0x3, + .have_slck_mck = 0, +}; + +struct clk_programmable_layout at91sam9g45_programmable_layout = { + .pres_shift = 2, + .css_mask = 0x3, + .have_slck_mck = 1, +}; + +struct clk_programmable_layout at91sam9x5_programmable_layout = { + .pres_shift = 4, + .css_mask = 0x7, + .have_slck_mck = 0, +}; + +#if defined(CONFIG_OF) +struct clk_prog_data { + struct clk **clks; + u8 *ids; + unsigned int clk_num; +}; + +static struct clk * __init +of_clk_src_periph_get(struct of_phandle_args *clkspec, void *data) +{ + struct clk_prog_data *clk_data = data; + unsigned int id = clkspec->args[0]; + int i; + + if (id >= PROG_MAX) + goto err; + + for (i = 0; i < clk_data->clk_num; i++) { + if (clk_data->ids[i] == id) + return clk_data->clks[i]; + } + +err: + pr_err("%s: invalid clock id %d\n", __func__, id); + return ERR_PTR(-EINVAL); +} + +static void __init +of_at91_clk_prog_setup(struct device_node *np, + struct clk_programmable_layout *layout) +{ + int num; + u32 id; + int i; + struct clk *clk; + int num_parents; + u8 *ids; + struct clk **clks; + struct clk_prog_data *clktab; + const char *parent_names[PROG_SOURCE_MAX]; + const char *name = np->name; + + num_parents = of_count_phandle_with_args(np, "clocks", "#clock-cells"); + if (num_parents <= 0 || num_parents > PROG_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; + } + + if (!of_get_property(np, "ids", &num)) + return; + + num /= 4; + if (num > PROG_MAX) + return; + + if (of_property_count_strings(np, "clock-output-names") != num) + return; + + clktab = kzalloc(sizeof(*clktab), GFP_KERNEL); + if (!clktab) + return; + + ids = kzalloc(num * sizeof(*ids), GFP_KERNEL); + if (!ids) + goto out_free_clktab; + + clks = kzalloc(num * sizeof(*clks), GFP_KERNEL); + if (!clks) + goto out_free_ids; + + for (i = 0; i < num; i++) { + of_property_read_u32_index(np, "ids", i, &id); + if (id >= PROG_MAX) + goto out_free_clks; + of_property_read_string_index(np, "clock-output-names", + i, &name); + clk = at91_clk_register_programmable(name, parent_names, + num_parents, id, layout); + + if (IS_ERR(clk)) + goto out_free_clks; + clks[i] = clk; + ids[i] = id; + } + + clktab->clk_num = num; + clktab->clks = clks; + clktab->ids = ids; + of_clk_add_provider(np, of_clk_src_periph_get, clktab); + return; + +out_free_clks: + kfree(clks); +out_free_ids: + kfree(ids); +out_free_clktab: + kfree(clktab); +} + + +static void __init of_at91rm9200_clk_prog_setup(struct device_node *np) +{ + of_at91_clk_prog_setup(np, &at91rm9200_programmable_layout); +} +CLK_OF_DECLARE(at91rm9200_clk_prog, "atmel,at91rm9200-clk-programmable", + of_at91rm9200_clk_prog_setup); + +static void __init of_at91sam9g45_clk_prog_setup(struct device_node *np) +{ + of_at91_clk_prog_setup(np, &at91sam9g45_programmable_layout); +} +CLK_OF_DECLARE(at91sam9g45_clk_prog, "atmel,at91sam9g45-clk-programmable", + of_at91sam9g45_clk_prog_setup); + +static void __init of_at91sam9x5_clk_prog_setup(struct device_node *np) +{ + of_at91_clk_prog_setup(np, &at91sam9x5_programmable_layout); +} +CLK_OF_DECLARE(at91sam9x5_clk_prog, "atmel,at91sam9x5-clk-programmable", + of_at91sam9x5_clk_prog_setup); +#endif diff --git a/include/linux/clk/at91.h b/include/linux/clk/at91.h index 4addfd6..eccdf74 100644 --- a/include/linux/clk/at91.h +++ b/include/linux/clk/at91.h @@ -221,6 +221,12 @@ struct clk_master_layout { u8 pres_shift; }; +struct clk_programmable_layout { + u8 pres_shift; + u8 css_mask; + u8 have_slck_mck; +}; + struct clk * __init at91_clk_register_main(const char *name, @@ -267,4 +273,16 @@ struct clk * __init at91_clk_register_sam9x5_peripheral(const char *name, const char *parent_name, u32 id, u32 default_div); + +extern struct clk_programmable_layout at91rm9200_programmable_layout; + +extern struct clk_programmable_layout at91sam9g45_programmable_layout; + +extern struct clk_programmable_layout at91sam9x5_programmable_layout; + +struct clk * __init +at91_clk_register_programmable(const char *name, const char **parent_names, + u8 num_parents, u8 id, + struct clk_programmable_layout *layout); + #endif -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/