From patchwork Sat Sep 10 23:20:15 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marek Vasut X-Patchwork-Id: 12972728 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 85750C6FA82 for ; Sat, 10 Sep 2022 23:20:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229514AbiIJXUi (ORCPT ); Sat, 10 Sep 2022 19:20:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41220 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229706AbiIJXUi (ORCPT ); Sat, 10 Sep 2022 19:20:38 -0400 Received: from phobos.denx.de (phobos.denx.de [IPv6:2a01:238:438b:c500:173d:9f52:ddab:ee01]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CF98C27152 for ; Sat, 10 Sep 2022 16:20:36 -0700 (PDT) Received: from tr.lan (ip-86-49-12-201.bb.vodafone.cz [86.49.12.201]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: marex@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id 6C9E4845C3; Sun, 11 Sep 2022 01:20:34 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1662852034; bh=STBFrQ1CVzqFty4EsqIatIRHVyvQMGmOjuH4i21Yfa8=; h=From:To:Cc:Subject:Date:From; b=Ox1Jo7gWW2mBp8Gj+URGGEq9miert4h0ap+XSWFyQk8lRsib598M+DdpaCr0BPAAp 4Mf3N3sREyWM8sa75DmKdJElIuEPavM0Rr5k/f+Z35jwDn85otEuZODnw4dEuLSYyK d5xHrRw2Dyv13Su3FUjpy6j76K6V8X6bCI73UGO+8TfZoSGKBDkikvPkL0CRU9d6ac vz69A2YGSAiCaRreKMjUhHGBGQQfc7C59D4/86PoFFpzHbkcGuibDKIn2VQW9HcVCT W3oMfbQOJjzhZ0A64j61QuxmatiqYYVsPDIAt4CKNiaDSqbjbwZJubaLRmyWMASoKS Pgd/nsisnAu1A== From: Marek Vasut To: linux-clk@vger.kernel.org Cc: Marek Vasut , Alexander Stein , Michael Turquette , Stephen Boyd Subject: [PATCH] clk: rs9: Fix I2C accessors Date: Sun, 11 Sep 2022 01:20:15 +0200 Message-Id: <20220910232015.216329-1-marex@denx.de> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 X-Virus-Scanned: clamav-milter 0.103.6 at phobos.denx.de X-Virus-Status: Clean Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org Add custom I2C accessors to this driver, since the regular I2C regmap ones do not generate the exact I2C transfers required by the chip. On I2C write, it is mandatory to send transfer length first, on read the chip returns the transfer length in first byte. Instead of always reading back 8 bytes, which is the default and also the size of the entire register file, set BCP register to 1 to read out 1 byte which is less wasteful. Fixes: 892e0ddea1aa6 ("clk: rs9: Add Renesas 9-series PCIe clock generator driver") Reported-by: Alexander Stein Signed-off-by: Marek Vasut --- Cc: Alexander Stein Cc: Michael Turquette Cc: Stephen Boyd --- drivers/clk/clk-renesas-pcie.c | 53 +++++++++++++++++++++++++++++++++- 1 file changed, 52 insertions(+), 1 deletion(-) diff --git a/drivers/clk/clk-renesas-pcie.c b/drivers/clk/clk-renesas-pcie.c index 4f5df1fc74b46..711ba443f33b7 100644 --- a/drivers/clk/clk-renesas-pcie.c +++ b/drivers/clk/clk-renesas-pcie.c @@ -90,6 +90,49 @@ static const struct regmap_access_table rs9_writeable_table = { .n_yes_ranges = ARRAY_SIZE(rs9_writeable_ranges), }; +static int rs9_regmap_i2c_write(void *context, unsigned int reg, unsigned int val) +{ + struct i2c_client *i2c = context; + const u8 data[3] = { reg, 1, val }; + const int count = ARRAY_SIZE(data); + int ret; + + ret = i2c_master_send(i2c, data, count); + if (ret == count) + return 0; + else if (ret < 0) + return ret; + else + return -EIO; +} + +static int rs9_regmap_i2c_read(void *context, + unsigned int reg, unsigned int *val) +{ + struct i2c_client *i2c = context; + struct i2c_msg xfer[2]; + u8 data[2]; + int ret; + + xfer[0].addr = i2c->addr; + xfer[0].flags = 0; + xfer[0].len = 1; + xfer[0].buf = (void *)® + + xfer[1].addr = i2c->addr; + xfer[1].flags = I2C_M_RD | I2C_M_RECV_LEN; + xfer[1].len = 1; + xfer[1].buf = (void *)data; + + ret = i2c_transfer(i2c->adapter, xfer, 2); + if (ret == 2) + return 0; + else if (ret < 0) + return ret; + else + return -EIO; +} + static const struct regmap_config rs9_regmap_config = { .reg_bits = 8, .val_bits = 8, @@ -97,6 +140,8 @@ static const struct regmap_config rs9_regmap_config = { .max_register = 0x8, .rd_table = &rs9_readable_table, .wr_table = &rs9_writeable_table, + .reg_write = rs9_regmap_i2c_write, + .reg_read = rs9_regmap_i2c_read, }; static int rs9_get_output_config(struct rs9_driver_data *rs9, int idx) @@ -242,11 +287,17 @@ static int rs9_probe(struct i2c_client *client) return ret; } - rs9->regmap = devm_regmap_init_i2c(client, &rs9_regmap_config); + rs9->regmap = devm_regmap_init(&client->dev, NULL, + client, &rs9_regmap_config); if (IS_ERR(rs9->regmap)) return dev_err_probe(&client->dev, PTR_ERR(rs9->regmap), "Failed to allocate register map\n"); + /* Always read back 1 Byte via I2C */ + ret = regmap_write(rs9->regmap, RS9_REG_BCP, 1); + if (ret < 0) + return ret; + /* Register clock */ for (i = 0; i < rs9->chip_info->num_clks; i++) { snprintf(name, 5, "DIF%d", i);