From patchwork Mon May 13 08:20:59 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Prisk X-Patchwork-Id: 2556961 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) by patchwork1.kernel.org (Postfix) with ESMTP id B63683FC5A for ; Mon, 13 May 2013 08:25:27 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Ubo1z-0007vc-Vs; Mon, 13 May 2013 08:22:54 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Ubo0r-0007PO-Qe; Mon, 13 May 2013 08:21:41 +0000 Received: from server.prisktech.co.nz ([115.188.14.127]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Ubo0Z-0007MS-R5 for linux-arm-kernel@lists.infradead.org; Mon, 13 May 2013 08:21:25 +0000 Received: from localhost.localdomain (unknown [192.168.0.102]) by server.prisktech.co.nz (Postfix) with ESMTP id EF0D6FC0DAE; Mon, 13 May 2013 20:21:06 +1200 (NZST) From: Tony Prisk To: Mike Turquette Subject: [PATCH 1/2] clk: vt8500: Add support for clocks on the WM8850 SoCs Date: Mon, 13 May 2013 20:20:59 +1200 Message-Id: <1368433260-16073-2-git-send-email-linux@prisktech.co.nz> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1368433260-16073-1-git-send-email-linux@prisktech.co.nz> References: <1368433260-16073-1-git-send-email-linux@prisktech.co.nz> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130513_042124_416941_D0791602 X-CRM114-Status: GOOD ( 17.79 ) X-Spam-Score: -2.5 (--) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-2.5 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.6 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: vt8500-wm8505-linux-kernel@googlegroups.com, Tony Prisk , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org The WM8850 has a different PLL clock to the previous versions. This patch adds support for the WM8850-style PLL clocks. Signed-off-by: Tony Prisk --- Documentation/devicetree/bindings/clock/vt8500.txt | 2 + drivers/clk/clk-vt8500.c | 71 ++++++++++++++++++++ 2 files changed, 73 insertions(+) diff --git a/Documentation/devicetree/bindings/clock/vt8500.txt b/Documentation/devicetree/bindings/clock/vt8500.txt index a880c70..91d71cc 100644 --- a/Documentation/devicetree/bindings/clock/vt8500.txt +++ b/Documentation/devicetree/bindings/clock/vt8500.txt @@ -8,6 +8,8 @@ Required properties: - compatible : shall be one of the following: "via,vt8500-pll-clock" - for a VT8500/WM8505 PLL clock "wm,wm8650-pll-clock" - for a WM8650 PLL clock + "wm,wm8750-pll-clock" - for a WM8750 PLL clock + "wm,wm8850-pll-clock" - for a WM8850 PLL clock "via,vt8500-device-clock" - for a VT/WM device clock Required properties for PLL clocks: diff --git a/drivers/clk/clk-vt8500.c b/drivers/clk/clk-vt8500.c index debf688..6d5b6e9 100644 --- a/drivers/clk/clk-vt8500.c +++ b/drivers/clk/clk-vt8500.c @@ -42,6 +42,7 @@ struct clk_device { #define PLL_TYPE_VT8500 0 #define PLL_TYPE_WM8650 1 #define PLL_TYPE_WM8750 2 +#define PLL_TYPE_WM8850 3 struct clk_pll { struct clk_hw hw; @@ -327,6 +328,15 @@ CLK_OF_DECLARE(vt8500_device, "via,vt8500-device-clock", vtwm_device_clk_init); #define WM8750_BITS_TO_VAL(f, m, d1, d2) \ ((f << 24) | ((m - 1) << 16) | ((d1 - 1) << 8) | d2) +/* Helper macros for PLL_WM8850 */ +#define WM8850_PLL_MUL(x) ((((x >> 16) & 0x7F) + 1) * 2) +#define WM8850_PLL_DIV(x) ((((x >> 8) & 1) + 1) * (1 << (x & 3))) + +#define WM8850_BITS_TO_FREQ(r, m, d1, d2) \ + (r * ((m + 1) * 2) / ((d1+1) * (1 << d2))) + +#define WM8850_BITS_TO_VAL(m, d1, d2) \ + ((((m / 2) - 1) << 16) | ((d1 - 1) << 8) | d2) static void vt8500_find_pll_bits(unsigned long rate, unsigned long parent_rate, u32 *multiplier, u32 *prediv) @@ -466,6 +476,49 @@ static void wm8750_find_pll_bits(unsigned long rate, unsigned long parent_rate, *divisor2 = best_div2; } +static void wm8850_find_pll_bits(unsigned long rate, unsigned long parent_rate, + u32 *multiplier, u32 *divisor1, u32 *divisor2) +{ + u32 mul, div1, div2; + u32 best_mul, best_div1, best_div2; + unsigned long tclk, rate_err, best_err; + + best_err = (unsigned long)-1; + + /* Find the closest match (lower or equal to requested) */ + for (div1 = 1; div1 >= 0; div1--) + for (div2 = 3; div2 >= 0; div2--) + for (mul = 0; mul <= 127; mul++) { + tclk = parent_rate * ((mul + 1) * 2) / + ((div1 + 1) * (1 << div2)); + if (tclk > rate) + continue; + /* error will always be +ve */ + rate_err = rate - tclk; + if (rate_err == 0) { + *multiplier = mul; + *divisor1 = div1; + *divisor2 = div2; + return; + } + + if (rate_err < best_err) { + best_err = rate_err; + best_mul = mul; + best_div1 = div1; + best_div2 = div2; + } + } + + /* if we got here, it wasn't an exact match */ + pr_warn("%s: requested rate %lu, found rate %lu\n", __func__, rate, + rate - best_err); + + *multiplier = best_mul; + *divisor1 = best_div1; + *divisor2 = best_div2; +} + static int vtwm_pll_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long parent_rate) { @@ -489,6 +542,10 @@ static int vtwm_pll_set_rate(struct clk_hw *hw, unsigned long rate, wm8750_find_pll_bits(rate, parent_rate, &filter, &mul, &div1, &div2); pll_val = WM8750_BITS_TO_VAL(filter, mul, div1, div2); break; + case PLL_TYPE_WM8850: + wm8850_find_pll_bits(rate, parent_rate, &mul, &div1, &div2); + pll_val = WM8850_BITS_TO_VAL(mul, div1, div2); + break; default: pr_err("%s: invalid pll type\n", __func__); return 0; @@ -525,6 +582,10 @@ static long vtwm_pll_round_rate(struct clk_hw *hw, unsigned long rate, wm8750_find_pll_bits(rate, *prate, &filter, &mul, &div1, &div2); round_rate = WM8750_BITS_TO_FREQ(*prate, mul, div1, div2); break; + case PLL_TYPE_WM8850: + wm8850_find_pll_bits(rate, *prate, &mul, &div1, &div2); + round_rate = WM8850_BITS_TO_FREQ(*prate, mul, div1, div2); + break; default: round_rate = 0; } @@ -552,6 +613,10 @@ static unsigned long vtwm_pll_recalc_rate(struct clk_hw *hw, pll_freq = parent_rate * WM8750_PLL_MUL(pll_val); pll_freq /= WM8750_PLL_DIV(pll_val); break; + case PLL_TYPE_WM8850: + pll_freq = parent_rate * WM8850_PLL_MUL(pll_val); + pll_freq /= WM8850_PLL_DIV(pll_val); + break; default: pll_freq = 0; } @@ -628,6 +693,12 @@ static void __init wm8750_pll_init(struct device_node *node) } CLK_OF_DECLARE(wm8750_pll, "wm,wm8750-pll-clock", wm8750_pll_init); +static void __init wm8850_pll_init(struct device_node *node) +{ + vtwm_pll_clk_init(node, PLL_TYPE_WM8850); +} +CLK_OF_DECLARE(wm8850_pll, "wm,wm8850-pll-clock", wm8850_pll_init); + void __init vtwm_clk_init(void __iomem *base) { if (!base)