From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 51449C04A68 for ; Wed, 27 Jul 2022 17:10:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241231AbiG0RK3 (ORCPT ); Wed, 27 Jul 2022 13:10:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44850 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241601AbiG0RJS (ORCPT ); Wed, 27 Jul 2022 13:09:18 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D1D1850044; Wed, 27 Jul 2022 09:40:56 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7BC7960DDB; Wed, 27 Jul 2022 16:40:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 82859C433D6; Wed, 27 Jul 2022 16:40:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658940053; bh=nO9vN98lzG+8FMhdNslgASCIMtubLetqdATFaeG8C6o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pxi2Kg1zAOhs45d6rLvGHU12cwiKum404hulsITdtAqewZtItxPwuG4OjhaRGg5rJ WWqRCXal/ZsTOk4HqjreEOqVM4bZ+O0XPVtLjT3uYPBGVpomkC8zAh3QHTH0wMjw0Y t0yFxnFM3PrQjU4aIvXAn0WYBIVG/PDZJ4nAwT6I= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Trimarchi , Dario Binacchi , Sascha Hauer , Miquel Raynal , Sasha Levin Subject: [PATCH 5.15 071/201] mtd: rawnand: gpmi: validate controller clock rate Date: Wed, 27 Jul 2022 18:09:35 +0200 Message-Id: <20220727161029.886728305@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220727161026.977588183@linuxfoundation.org> References: <20220727161026.977588183@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dario Binacchi [ Upstream commit 15e27d197a7ea69b4643791ca2f8467fdd998359 ] What to do when the real rate of the gpmi clock is not equal to the required one? The solutions proposed in [1] did not lead to a conclusion on how to validate the clock rate, so, inspired by the document [2], I consider the rate correct only if not lower or equal to the rate of the previous edo mode. In fact, in chapter 4.16.2 (NV-DDR) of the document [2], it is written that "If the host selects timing mode n, then its clock period shall be faster than the clock period of timing mode n-1 and slower than or equal to the clock period of timing mode n.". I thought that it could therefore also be used in this case, without therefore having to define the valid rate ranges empirically. For example, suppose that gpmi_nfc_compute_timings() is called to set edo mode 5 (100MHz) but the rate returned by clk_round_rate() is 80MHz (edo mode 4). In this case gpmi_nfc_compute_timings() will return error, and will be called again to set edo mode 4, which this time will be successful. [1] https://lore.kernel.org/r/20210702065350.209646-5-ebiggers@kernel.org [2] http://www.onfi.org/-/media/client/onfi/specs/onfi_3_0_gold.pdf?la=en Co-developed-by: Michael Trimarchi Signed-off-by: Michael Trimarchi Signed-off-by: Dario Binacchi Tested-by: Sascha Hauer Reviewed-by: Sascha Hauer Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20220118095434.35081-4-dario.binacchi@amarulasolutions.com Signed-off-by: Sasha Levin --- drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c index b72b387c08ef..62f4988c2a5f 100644 --- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c +++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c @@ -644,8 +644,8 @@ static int bch_set_geometry(struct gpmi_nand_data *this) * RDN_DELAY = ----------------------- {3} * RP */ -static void gpmi_nfc_compute_timings(struct gpmi_nand_data *this, - const struct nand_sdr_timings *sdr) +static int gpmi_nfc_compute_timings(struct gpmi_nand_data *this, + const struct nand_sdr_timings *sdr) { struct gpmi_nfc_hardware_timing *hw = &this->hw; struct resources *r = &this->resources; @@ -657,23 +657,33 @@ static void gpmi_nfc_compute_timings(struct gpmi_nand_data *this, int sample_delay_ps, sample_delay_factor; u16 busy_timeout_cycles; u8 wrn_dly_sel; + unsigned long clk_rate, min_rate; if (sdr->tRC_min >= 30000) { /* ONFI non-EDO modes [0-3] */ hw->clk_rate = 22000000; + min_rate = 0; wrn_dly_sel = BV_GPMI_CTRL1_WRN_DLY_SEL_4_TO_8NS; } else if (sdr->tRC_min >= 25000) { /* ONFI EDO mode 4 */ hw->clk_rate = 80000000; + min_rate = 22000000; wrn_dly_sel = BV_GPMI_CTRL1_WRN_DLY_SEL_NO_DELAY; } else { /* ONFI EDO mode 5 */ hw->clk_rate = 100000000; + min_rate = 80000000; wrn_dly_sel = BV_GPMI_CTRL1_WRN_DLY_SEL_NO_DELAY; } - hw->clk_rate = clk_round_rate(r->clock[0], hw->clk_rate); + clk_rate = clk_round_rate(r->clock[0], hw->clk_rate); + if (clk_rate <= min_rate) { + dev_err(this->dev, "clock setting: expected %ld, got %ld\n", + hw->clk_rate, clk_rate); + return -ENOTSUPP; + } + hw->clk_rate = clk_rate; /* SDR core timings are given in picoseconds */ period_ps = div_u64((u64)NSEC_PER_SEC * 1000, hw->clk_rate); @@ -714,6 +724,7 @@ static void gpmi_nfc_compute_timings(struct gpmi_nand_data *this, hw->ctrl1n |= BF_GPMI_CTRL1_RDN_DELAY(sample_delay_factor) | BM_GPMI_CTRL1_DLL_ENABLE | (use_half_period ? BM_GPMI_CTRL1_HALF_PERIOD : 0); + return 0; } static int gpmi_nfc_apply_timings(struct gpmi_nand_data *this) @@ -769,6 +780,7 @@ static int gpmi_setup_interface(struct nand_chip *chip, int chipnr, { struct gpmi_nand_data *this = nand_get_controller_data(chip); const struct nand_sdr_timings *sdr; + int ret; /* Retrieve required NAND timings */ sdr = nand_get_sdr_timings(conf); @@ -784,7 +796,9 @@ static int gpmi_setup_interface(struct nand_chip *chip, int chipnr, return 0; /* Do the actual derivation of the controller timings */ - gpmi_nfc_compute_timings(this, sdr); + ret = gpmi_nfc_compute_timings(this, sdr); + if (ret) + return ret; this->hw.must_apply_timings = true; -- 2.35.1