From patchwork Wed Jun 27 11:01:33 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rajendra Nayak X-Patchwork-Id: 167620 Return-Path: X-Original-To: incoming-imx@patchwork.ozlabs.org Delivered-To: patchwork-incoming-imx@bilbo.ozlabs.org Received: from merlin.infradead.org (unknown [IPv6:2001:4978:20e::2]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 341471007D4 for ; Wed, 27 Jun 2012 21:06:37 +1000 (EST) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1Sjq0H-0001dn-L0; Wed, 27 Jun 2012 11:01:45 +0000 Received: from devils.ext.ti.com ([198.47.26.153]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Sjq0D-0001dC-DX for linux-arm-kernel@lists.infradead.org; Wed, 27 Jun 2012 11:01:42 +0000 Received: from dbdp20.itg.ti.com ([172.24.170.38]) by devils.ext.ti.com (8.13.7/8.13.7) with ESMTP id q5RB1cEp005717; Wed, 27 Jun 2012 06:01:39 -0500 Received: from DBDE71.ent.ti.com (localhost [127.0.0.1]) by dbdp20.itg.ti.com (8.13.8/8.13.8) with ESMTP id q5RB1bg3026671; Wed, 27 Jun 2012 16:31:37 +0530 (IST) Received: from dbdp32.itg.ti.com (172.24.170.251) by DBDE71.ent.ti.com (172.24.170.149) with Microsoft SMTP Server id 14.1.323.3; Wed, 27 Jun 2012 16:31:37 +0530 Received: from ula0131687.apr.dhcp.ti.com (smtpvbd.itg.ti.com [172.24.170.250]) by dbdp32.itg.ti.com (8.13.8/8.13.8) with ESMTP id q5RB1Yra032448; Wed, 27 Jun 2012 16:31:34 +0530 From: Rajendra Nayak To: Subject: [PATCH v2] clk: Add support for rate table based dividers Date: Wed, 27 Jun 2012 16:31:33 +0530 Message-ID: <1340794893-20869-1-git-send-email-rnayak@ti.com> X-Mailer: git-send-email 1.7.1 MIME-Version: 1.0 X-Spam-Note: CRM114 invocation failed X-Spam-Score: -6.9 (------) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-6.9 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at http://www.dnswl.org/, high trust [198.47.26.153 listed in list.dnswl.org] -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -0.0 SPF_PASS SPF: sender matches SPF record -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Sascha Hauer , Rajendra Nayak , Viresh Kumar , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+incoming-imx=patchwork.ozlabs.org@lists.infradead.org List-Id: linux-imx-kernel.lists.patchwork.ozlabs.org Some divider clks do not have any obvious relationship between the divider and the value programmed in the register. For instance, say a value of 1 could signify divide by 6 and a value of 2 could signify divide by 4 etc. Also there are dividers where not all values possible based on the bitfield width are valid. For instance a 3 bit wide bitfield can be used to program a value from 0 to 7. However its possible that only 0 to 4 are valid values. All these cases need the platform code to pass a simple table of divider/value tuple, so the framework knows the exact value to be written based on the divider calculation and can also do better error checking. This patch adds support for such rate table based dividers. Also since this means adding a new parameter to the clk_register_divider(), update all existing users of it. Signed-off-by: Rajendra Nayak Cc: Sascha Hauer Cc: Viresh Kumar --- arch/arm/mach-imx/clk.h | 2 +- drivers/clk/clk-divider.c | 67 ++++++++++++++++++++++++++++++++++-- drivers/clk/spear/spear3xx_clock.c | 4 +- drivers/clk/spear/spear6xx_clock.c | 4 +- include/linux/clk-private.h | 3 +- include/linux/clk-provider.h | 10 +++++- 6 files changed, 80 insertions(+), 10 deletions(-) diff --git a/arch/arm/mach-imx/clk.h b/arch/arm/mach-imx/clk.h index 1bf64fe..8cb6f97 100644 --- a/arch/arm/mach-imx/clk.h +++ b/arch/arm/mach-imx/clk.h @@ -56,7 +56,7 @@ static inline struct clk *imx_clk_divider(const char *name, const char *parent, void __iomem *reg, u8 shift, u8 width) { return clk_register_divider(NULL, name, parent, CLK_SET_RATE_PARENT, - reg, shift, width, 0, &imx_ccm_lock); + reg, shift, width, 0, , NULL, &imx_ccm_lock); } static inline struct clk *imx_clk_gate(const char *name, const char *parent, diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c index e548c43..71e2466 100644 --- a/drivers/clk/clk-divider.c +++ b/drivers/clk/clk-divider.c @@ -32,30 +32,69 @@ #define div_mask(d) ((1 << (d->width)) - 1) #define is_power_of_two(i) !(i & ~i) +static unsigned int _get_table_maxdiv(const struct clk_div_table *table) +{ + unsigned int maxdiv = 0; + const struct clk_div_table *clkt; + + for (clkt = table; clkt->div; clkt++) + if (clkt->div > maxdiv) + maxdiv = clkt->div; + return maxdiv; +} + static unsigned int _get_maxdiv(struct clk_divider *divider) { if (divider->flags & CLK_DIVIDER_ONE_BASED) return div_mask(divider); if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) return 1 << div_mask(divider); + if (divider->table) + return _get_table_maxdiv(divider->table); return div_mask(divider) + 1; } +static unsigned int _get_table_div(const struct clk_div_table *table, + unsigned int val) +{ + const struct clk_div_table *clkt; + + for (clkt = table; clkt->div; clkt++) + if (clkt->val == val) + return clkt->div; + return 0; +} + static unsigned int _get_div(struct clk_divider *divider, unsigned int val) { if (divider->flags & CLK_DIVIDER_ONE_BASED) return val; if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) return 1 << val; + if (divider->table) + return _get_table_div(divider->table, val); return val + 1; } +static unsigned int _get_table_val(const struct clk_div_table *table, + unsigned int div) +{ + const struct clk_div_table *clkt; + + for (clkt = table; clkt->div; clkt++) + if (clkt->div == div) + return clkt->val; + return 0; +} + static unsigned int _get_val(struct clk_divider *divider, u8 div) { if (divider->flags & CLK_DIVIDER_ONE_BASED) return div; if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) return __ffs(div); + if (divider->table) + return _get_table_val(divider->table, div); return div - 1; } @@ -84,6 +123,26 @@ static unsigned long clk_divider_recalc_rate(struct clk_hw *hw, */ #define MULT_ROUND_UP(r, m) ((r) * (m) + (m) - 1) +static bool _is_valid_table_div(const struct clk_div_table *table, + unsigned int div) +{ + const struct clk_div_table *clkt; + + for (clkt = table; clkt->div; clkt++) + if (clkt->div == div) + return true; + return false; +} + +static bool _is_valid_div(struct clk_divider *divider, unsigned int div) +{ + if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) + return is_power_of_two(div); + if (divider->table) + return _is_valid_table_div(divider->table, div); + return true; +} + static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, unsigned long *best_parent_rate) { @@ -111,8 +170,7 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, maxdiv = min(ULONG_MAX / rate, maxdiv); for (i = 1; i <= maxdiv; i++) { - if ((divider->flags & CLK_DIVIDER_POWER_OF_TWO) - && (!is_power_of_two(i))) + if (!_is_valid_div(divider, i)) continue; parent_rate = __clk_round_rate(__clk_get_parent(hw->clk), MULT_ROUND_UP(rate, i)); @@ -186,12 +244,14 @@ EXPORT_SYMBOL_GPL(clk_divider_ops); * @shift: number of bits to shift the bitfield * @width: width of the bitfield * @clk_divider_flags: divider-specific flags for this clock + * @table: array of divider/value pairs ending with a div set to 0 * @lock: shared register lock for this clock */ struct clk *clk_register_divider(struct device *dev, const char *name, const char *parent_name, unsigned long flags, void __iomem *reg, u8 shift, u8 width, - u8 clk_divider_flags, spinlock_t *lock) + u8 clk_divider_flags, const struct clk_div_table *table, + spinlock_t *lock) { struct clk_divider *div; struct clk *clk; @@ -217,6 +277,7 @@ struct clk *clk_register_divider(struct device *dev, const char *name, div->flags = clk_divider_flags; div->lock = lock; div->hw.init = &init; + div->table = table; /* register the clock */ clk = clk_register(dev, &div->hw); diff --git a/drivers/clk/spear/spear3xx_clock.c b/drivers/clk/spear/spear3xx_clock.c index 01dd6da..b00e1e0 100644 --- a/drivers/clk/spear/spear3xx_clock.c +++ b/drivers/clk/spear/spear3xx_clock.c @@ -389,7 +389,7 @@ void __init spear3xx_clk_init(void) clk = clk_register_divider(NULL, "ahb_clk", "pll1_clk", CLK_SET_RATE_PARENT, CORE_CLK_CFG, HCLK_RATIO_SHIFT, - HCLK_RATIO_MASK, 0, &_lock); + HCLK_RATIO_MASK, 0, NULL, &_lock); clk_register_clkdev(clk, "ahb_clk", NULL); clk = clk_register_aux("uart_synth_clk", "uart_synth_gate_clk", @@ -510,7 +510,7 @@ void __init spear3xx_clk_init(void) clk = clk_register_divider(NULL, "apb_clk", "ahb_clk", CLK_SET_RATE_PARENT, CORE_CLK_CFG, PCLK_RATIO_SHIFT, - PCLK_RATIO_MASK, 0, &_lock); + PCLK_RATIO_MASK, 0, NULL, &_lock); clk_register_clkdev(clk, "apb_clk", NULL); clk = clk_register_gate(NULL, "amem_clk", "ahb_clk", 0, AMEM_CLK_CFG, diff --git a/drivers/clk/spear/spear6xx_clock.c b/drivers/clk/spear/spear6xx_clock.c index 61026ae..2b26163 100644 --- a/drivers/clk/spear/spear6xx_clock.c +++ b/drivers/clk/spear/spear6xx_clock.c @@ -162,7 +162,7 @@ void __init spear6xx_clk_init(void) clk = clk_register_divider(NULL, "ahb_clk", "pll1_clk", CLK_SET_RATE_PARENT, CORE_CLK_CFG, HCLK_RATIO_SHIFT, - HCLK_RATIO_MASK, 0, &_lock); + HCLK_RATIO_MASK, 0, NULL, &_lock); clk_register_clkdev(clk, "ahb_clk", NULL); clk = clk_register_aux("uart_synth_clk", "uart_synth_gate_clk", @@ -285,7 +285,7 @@ void __init spear6xx_clk_init(void) clk = clk_register_divider(NULL, "apb_clk", "ahb_clk", CLK_SET_RATE_PARENT, CORE_CLK_CFG, PCLK_RATIO_SHIFT, - PCLK_RATIO_MASK, 0, &_lock); + PCLK_RATIO_MASK, 0, NULL, &_lock); clk_register_clkdev(clk, "apb_clk", NULL); clk = clk_register_gate(NULL, "dma_clk", "ahb_clk", 0, PERIP1_CLK_ENB, diff --git a/include/linux/clk-private.h b/include/linux/clk-private.h index eb3f84b..2479239 100644 --- a/include/linux/clk-private.h +++ b/include/linux/clk-private.h @@ -105,7 +105,7 @@ struct clk { #define DEFINE_CLK_DIVIDER(_name, _parent_name, _parent_ptr, \ _flags, _reg, _shift, _width, \ - _divider_flags, _lock) \ + _divider_flags, _table, _lock) \ static struct clk _name; \ static const char *_name##_parent_names[] = { \ _parent_name, \ @@ -121,6 +121,7 @@ struct clk { .shift = _shift, \ .width = _width, \ .flags = _divider_flags, \ + .table = _table, \ .lock = _lock, \ }; \ DEFINE_CLK(_name, clk_divider_ops, _flags, \ diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 1a8e8ad..aa63aca 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -203,6 +203,11 @@ struct clk *clk_register_gate(struct device *dev, const char *name, void __iomem *reg, u8 bit_idx, u8 clk_gate_flags, spinlock_t *lock); +struct clk_div_table { + unsigned int val; + unsigned int div; +}; + /** * struct clk_divider - adjustable divider clock * @@ -210,6 +215,7 @@ struct clk *clk_register_gate(struct device *dev, const char *name, * @reg: register containing the divider * @shift: shift to the divider bit field * @width: width of the divider bit field + * @table: array of value/divider pairs, last entry should have div = 0 * @lock: register lock * * Clock with an adjustable divider affecting its output frequency. Implements @@ -229,6 +235,7 @@ struct clk_divider { u8 shift; u8 width; u8 flags; + const struct clk_div_table *table; spinlock_t *lock; }; @@ -239,7 +246,8 @@ extern const struct clk_ops clk_divider_ops; struct clk *clk_register_divider(struct device *dev, const char *name, const char *parent_name, unsigned long flags, void __iomem *reg, u8 shift, u8 width, - u8 clk_divider_flags, spinlock_t *lock); + u8 clk_divider_flags, const struct clk_div_table *table, + spinlock_t *lock); /** * struct clk_mux - multiplexer clock