From patchwork Thu Aug 29 13:27:53 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Ivan T. Ivanov" X-Patchwork-Id: 2851365 Return-Path: X-Original-To: patchwork-linux-arm-msm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id C84E4BF546 for ; Thu, 29 Aug 2013 13:29:26 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 60E2920315 for ; Thu, 29 Aug 2013 13:29:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A4ABF2030E for ; Thu, 29 Aug 2013 13:29:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753334Ab3H2N3Q (ORCPT ); Thu, 29 Aug 2013 09:29:16 -0400 Received: from ns.mm-sol.com ([212.124.72.66]:40266 "EHLO extserv.mm-sol.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753078Ab3H2N3O (ORCPT ); Thu, 29 Aug 2013 09:29:14 -0400 Received: from iivanov-dev.int.mm-sol.com (unknown [172.18.0.3]) by extserv.mm-sol.com (Postfix) with ESMTPSA id CA999C69C; Thu, 29 Aug 2013 16:29:12 +0300 (EEST) From: "Ivan T. Ivanov" To: wsa@the-dreams.de Cc: rob.herring@calxeda.com, pawel.moll@arm.com, mark.rutland@arm.com, swarren@wwwdotorg.org, ian.campbell@citrix.com, rob@landley.net, grant.likely@linaro.org, gavidov@codeaurora.org, sdharia@codeaurora.org, alokc@codeaurora.org, linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel, linux-arm-msm@vger.kernel.org, "Ivan T. Ivanov" Subject: [PATCH 2/2] i2c: New bus driver for the QUP I2C controller Date: Thu, 29 Aug 2013 16:27:53 +0300 Message-Id: <1377782873-31931-2-git-send-email-iivanov@mm-sol.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1377782873-31931-1-git-send-email-iivanov@mm-sol.com> References: <1377782873-31931-1-git-send-email-iivanov@mm-sol.com> Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org X-Spam-Status: No, score=-9.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: "Ivan T. Ivanov" This bus driver supports the QUP i2c hardware controller in the Qualcomm MSM SOCs. The Qualcomm Universal Peripheral Engine (QUP) is a general purpose data path engine with input/output FIFOs and an embedded i2c mini-core. The driver supports FIFO mode (for low bandwidth applications) and block mode (interrupt generated for each block-size data transfer). The driver currently does not support DMA transfers. Shamelessly based on codeaurora version of the driver. This controller could be found in the following chip-sets: msm9625, msm8974, msm8610, msm8226, mpq8092. Signed-off-by: Ivan T. Ivanov --- drivers/i2c/busses/Kconfig | 10 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-qup.c | 909 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 920 insertions(+) create mode 100644 drivers/i2c/busses/i2c-qup.c diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index fcdd321..c76ddd4 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -777,6 +777,16 @@ config I2C_RCAR This driver can also be built as a module. If so, the module will be called i2c-rcar. +config I2C_QUP + tristate "Qualcomm QUP based I2C controller" + depends on ARCH_MSM + help + If you say yes to this option, support will be included for the + built-in I2C interface on the MSM family processors. + + This driver can also be built as a module. If so, the module + will be called i2c-qup. + comment "External I2C/SMBus adapter drivers" config I2C_DIOLAN_U2C diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index d00997f..77127df 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -76,6 +76,7 @@ obj-$(CONFIG_I2C_OCTEON) += i2c-octeon.o obj-$(CONFIG_I2C_XILINX) += i2c-xiic.o obj-$(CONFIG_I2C_XLR) += i2c-xlr.o obj-$(CONFIG_I2C_RCAR) += i2c-rcar.o +obj-$(CONFIG_I2C_QUP) += i2c-qup.o # External I2C/SMBus adapter drivers obj-$(CONFIG_I2C_DIOLAN_U2C) += i2c-diolan-u2c.o diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c new file mode 100644 index 0000000..3b5ef91 --- /dev/null +++ b/drivers/i2c/busses/i2c-qup.c @@ -0,0 +1,909 @@ +/* Copyright (c) 2009-2013, The Linux Foundation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ +/* + * QUP driver for Qualcomm MSM platforms + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* QUP Registers */ +#define QUP_CONFIG 0x000 +#define QUP_STATE 0x004 +#define QUP_IO_MODE 0x008 +#define QUP_SW_RESET 0x00c +#define QUP_OPERATIONAL 0x018 +#define QUP_ERROR_FLAGS 0x01c +#define QUP_ERROR_FLAGS_EN 0x020 +#define QUP_HW_VERSION 0x030 +#define QUP_MX_OUTPUT_CNT 0x100 +#define QUP_OUT_FIFO_BASE 0x110 +#define QUP_MX_WRITE_CNT 0x150 +#define QUP_MX_INPUT_CNT 0x200 +#define QUP_MX_READ_CNT 0x208 +#define QUP_IN_FIFO_BASE 0x218 +#define QUP_I2C_CLK_CTL 0x400 +#define QUP_I2C_STATUS 0x404 + +/* QUP States and reset values */ +#define QUP_RESET_STATE 0 +#define QUP_RUN_STATE 1 +#define QUP_PAUSE_STATE 3 +#define QUP_STATE_MASK 3 + +#define QUP_STATE_VALID BIT(2) +#define QUP_I2C_MAST_GEN BIT(4) + +#define QUP_OPERATIONAL_RESET 0x000ff0 +#define QUP_I2C_STATUS_RESET 0xfffffc + +/* QUP OPERATIONAL FLAGS */ +#define QUP_OUT_SVC_FLAG BIT(8) +#define QUP_IN_SVC_FLAG BIT(9) +#define QUP_MX_INPUT_DONE BIT(11) + +/* I2C mini core related values */ +#define I2C_MINI_CORE (2 << 8) +#define I2C_N_VAL 15 +/* Most significant word offset in FIFO port */ +#define QUP_MSW_SHIFT (I2C_N_VAL + 1) +#define QUP_CLOCK_AUTO_GATE BIT(13) + +/* Packing/Unpacking words in FIFOs, and IO modes */ +#define QUP_UNPACK_EN BIT(14) +#define QUP_PACK_EN BIT(15) +#define QUP_OUTPUT_BLK_MODE (1 << 10) +#define QUP_INPUT_BLK_MODE (1 << 12) + +#define QUP_REPACK_EN (QUP_UNPACK_EN | QUP_PACK_EN) + +#define QUP_OUTPUT_BLOCK_SIZE(x)(((x) & (0x03 << 0)) >> 0) +#define QUP_OUTPUT_FIFO_SIZE(x) (((x) & (0x07 << 2)) >> 2) +#define QUP_INPUT_BLOCK_SIZE(x) (((x) & (0x03 << 5)) >> 5) +#define QUP_INPUT_FIFO_SIZE(x) (((x) & (0x07 << 7)) >> 7) + +/* QUP tags */ +#define QUP_OUT_NOP (0 << 8) +#define QUP_OUT_START (1 << 8) +#define QUP_OUT_DATA (2 << 8) +#define QUP_OUT_STOP (3 << 8) +#define QUP_OUT_REC (4 << 8) +#define QUP_IN_DATA (5 << 8) +#define QUP_IN_STOP (6 << 8) +#define QUP_IN_NACK (7 << 8) + +/* Status, Error flags */ +#define I2C_STATUS_WR_BUFFER_FULL BIT(0) +#define I2C_STATUS_BUS_ACTIVE BIT(8) +#define I2C_STATUS_BUS_MASTER BIT(9) +#define I2C_STATUS_ERROR_MASK 0x38000fc +#define QUP_I2C_NACK_FLAG BIT(3) +#define QUP_IN_NOT_EMPTY BIT(5) +#define QUP_STATUS_ERROR_FLAGS 0x7c + +/* Master bus_err clock states */ +#define I2C_CLK_RESET_BUSIDLE_STATE 0 +#define I2C_CLK_FORCED_LOW_STATE 5 + +#define QUP_MAX_CLK_STATE_RETRIES 300 +#define DEFAULT_CLK_RATE 19200000 +#define I2C_STATUS_CLK_STATE 13 +#define QUP_OUT_FIFO_NOT_EMPTY 0x10 +#define QUP_READ_LIMIT 256 + +struct qup_i2c_dev { + struct device *dev; + void __iomem *base; + struct pinctrl *pctrl; + int irq; + struct clk *clk; + struct clk *pclk; + struct i2c_adapter adap; + + int src_clk_freq; + int clk_freq; + int clk_ctl; + int one_bit_t; + int out_fifo_sz; + int in_fifo_sz; + int out_blk_sz; + int in_blk_sz; + unsigned long xfer_time; + unsigned long wait_idle; + + struct i2c_msg *msg; + /* Current possion in user message buffer */ + int pos; + /* Keep number of bytes left to be transmitted */ + int cnt; + /* I2C protocol errors */ + u32 bus_err; + /* QUP core errors */ + u32 qup_err; + /* + * maximum bytes that could be send (per iterration). could be + * equal of fifo size or block size (in block mode) + */ + int chunk_sz; + struct completion xfer; +}; + +static irqreturn_t qup_i2c_interrupt(int irq, void *dev) +{ + struct qup_i2c_dev *qup = dev; + u32 bus_err; + u32 qup_err; + u32 opflags; + + bus_err = readl(qup->base + QUP_I2C_STATUS); + qup_err = readl(qup->base + QUP_ERROR_FLAGS); + opflags = readl(qup->base + QUP_OPERATIONAL); + + if (!qup->msg) { + /* Clear Error interrupt */ + writel(QUP_RESET_STATE, qup->base + QUP_STATE); + return IRQ_HANDLED; + } + + bus_err &= I2C_STATUS_ERROR_MASK; + qup_err &= QUP_STATUS_ERROR_FLAGS; + + if (qup_err) { + /* Clear Error interrupt */ + writel(qup_err & QUP_STATUS_ERROR_FLAGS, + qup->base + QUP_ERROR_FLAGS); + goto done; + } + + if (bus_err) { + /* Clear Error interrupt */ + writel(QUP_RESET_STATE, qup->base + QUP_STATE); + goto done; + } + + if (opflags & QUP_OUT_SVC_FLAG) + writel(QUP_OUT_SVC_FLAG, qup->base + QUP_OPERATIONAL); + + if (!(qup->msg->flags == I2C_M_RD)) + return IRQ_HANDLED; + + if ((opflags & QUP_MX_INPUT_DONE) || (opflags & QUP_IN_SVC_FLAG)) + writel(QUP_IN_SVC_FLAG, qup->base + QUP_OPERATIONAL); + +done: + qup->qup_err = qup_err; + qup->bus_err = bus_err; + complete(&qup->xfer); + return IRQ_HANDLED; +} + +static int +qup_i2c_poll_state(struct qup_i2c_dev *qup, u32 req_state, bool only_valid) +{ + int retries = 0; + u32 state; + + do { + state = readl(qup->base + QUP_STATE); + + /* + * If only valid bit needs to be checked, requested state is + * 'don't care' + */ + if (state & QUP_STATE_VALID) { + if (only_valid) + return 0; + if ((req_state & QUP_I2C_MAST_GEN) + && (state & QUP_I2C_MAST_GEN)) + return 0; + if ((state & QUP_STATE_MASK) == req_state) + return 0; + } + + if (retries++ == 1000) + udelay(100); + + } while (retries != 2000); + + return -ETIMEDOUT; +} + +static int qup_i2c_change_state(struct qup_i2c_dev *qup, u32 state) +{ + if (qup_i2c_poll_state(qup, 0, true) != 0) + return -EIO; + + writel(state, qup->base + QUP_STATE); + + if (qup_i2c_poll_state(qup, state, false) != 0) + return -EIO; + return 0; +} + +static void qup_i2c_enable(struct qup_i2c_dev *qup, bool state) +{ + u32 config; + + if (state) { + clk_prepare_enable(qup->clk); + clk_prepare_enable(qup->pclk); + } else { + qup_i2c_change_state(qup, QUP_RESET_STATE); + clk_disable_unprepare(qup->clk); + config = readl(qup->base + QUP_CONFIG); + config |= QUP_CLOCK_AUTO_GATE; + writel(config, qup->base + QUP_CONFIG); + clk_disable_unprepare(qup->pclk); + } +} + +static int qup_i2c_wait_idle(struct qup_i2c_dev *qup, struct i2c_msg *msg) +{ + bool buf_full, bus_active; + int retries = 0; + u32 status; + + do { + status = readl(qup->base + QUP_I2C_STATUS); + buf_full = status & I2C_STATUS_WR_BUFFER_FULL; + bus_active = status & I2C_STATUS_BUS_ACTIVE; + + if (!buf_full) { + if ((msg->flags & I2C_M_RD) && !bus_active) + return 0; + else if (msg->flags == 0) + return 0; + else /* 1-bit delay before we check for bus busy */ + udelay(qup->one_bit_t); + } + + if (retries++ == 1000) + usleep_range(qup->wait_idle, qup->wait_idle + 10); + + } while (retries != 2000); + + dev_err(qup->dev, "Timeout waiting bus idle\n"); + return -ETIMEDOUT; +} + +static void qup_i2c_wait_clock_ready(struct qup_i2c_dev *qup) +{ + u32 have_data, clk_state, bus_state; + int retries = 0; + + /* + * Wait for the clock state to transition to either IDLE or FORCED + * LOW. This will usually happen within one cycle of the i2c clock. + */ + do { + bus_state = readl(qup->base + QUP_I2C_STATUS); + clk_state = (bus_state >> I2C_STATUS_CLK_STATE) & 0x7; + + have_data = readl(qup->base + QUP_OPERATIONAL); + have_data &= QUP_OUT_FIFO_NOT_EMPTY; + + /* + * In very corner case when slave do clock stretching and + * output fifo will have 1 block of data space have_data at + * the same time. So i2c dev will get output service + * interrupt and as it doesn't have more data to be written. + * This can lead to issue where output fifo is not have_data. + */ + if (!have_data && + (clk_state == I2C_CLK_RESET_BUSIDLE_STATE || + clk_state == I2C_CLK_FORCED_LOW_STATE)) { + return; + } + + /* 1-bit delay before we check again */ + udelay(qup->one_bit_t); + } while (retries++ < QUP_MAX_CLK_STATE_RETRIES); + + dev_warn(qup->dev, "Timeout clk_state: %x buffer %sempty\n", clk_state, + have_data ? "not-" : ""); +} + +static void qup_i2c_set_read_mode(struct qup_i2c_dev *qup) +{ + /* + * QUP limit QUP_READ_LIMIT bytes per read. By HW design, 0 in the + * 8-bit field is treated as QUP_READ_LIMIT byte read. + */ + u16 len = (qup->cnt >= QUP_READ_LIMIT) ? QUP_READ_LIMIT : qup->cnt; + + if (len <= qup->in_fifo_sz) { + /* FIFO mode */ + writel(QUP_REPACK_EN, qup->base + QUP_IO_MODE); + writel(len, qup->base + QUP_MX_READ_CNT); + } else { + /* BLOCK mode (transfer data on chunks) */ + writel(QUP_INPUT_BLK_MODE | QUP_REPACK_EN, + qup->base + QUP_IO_MODE); + writel(len, qup->base + QUP_MX_INPUT_CNT); + } +} + +static void qup_i2c_issue_read(struct qup_i2c_dev *qup, struct i2c_msg *msg) +{ + u32 addr = (msg->addr << 1) | 1; + /* + * QUP limit 256 bytes per read. By HW design, 0 in the + * 8-bit field is treated as 256 byte read. + */ + u32 len = (qup->cnt >= QUP_READ_LIMIT) ? 0 : qup->cnt; + u32 val; + + val = ((QUP_OUT_REC | len) << QUP_MSW_SHIFT) | QUP_OUT_START | addr; + + writel(val, qup->base + QUP_OUT_FIFO_BASE); +} + + +static void qup_i2c_read_fifo(struct qup_i2c_dev *qup, struct i2c_msg *msg) +{ + u32 val, stat; + int idx; + + val = 0; + for (idx = 0; qup->pos < msg->len; idx++, qup->pos++, qup->cnt--) { + if ((idx & 1) == 0) { + /* Check that FIFO have_data */ + stat = readl(qup->base + QUP_OPERATIONAL); + if ((stat & QUP_IN_NOT_EMPTY) == 0) + break; + + /* Reading 2 words at time */ + val = readl(qup->base + QUP_IN_FIFO_BASE); + + msg->buf[qup->pos] = val & 0xFF; + } else { + msg->buf[qup->pos] = val >> QUP_MSW_SHIFT; + } + } +} + +static bool +qup_i2c_set_write_mode(struct qup_i2c_dev *qup, struct i2c_msg *msg) +{ + bool block = false; + int total; + + if (msg->len <= qup->out_fifo_sz) { + /* FIFO mode */ + writel(QUP_REPACK_EN, qup->base + QUP_IO_MODE); + } else { + /* BLOCK mode (transfer data on chunks) */ + total = msg->len + 1 + (msg->len / (qup->out_blk_sz - 1)); + writel(QUP_OUTPUT_BLK_MODE | QUP_REPACK_EN, + qup->base + QUP_IO_MODE); + writel(total, qup->base + QUP_MX_OUTPUT_CNT); + block = true; + } + + return block; +} + +static void qup_i2c_issue_write(struct qup_i2c_dev *qup, struct i2c_msg *msg) +{ + u32 addr = msg->addr << 1; + u32 val, qup_tag; + int idx, entries; + + if (qup->pos == 0) { + val = QUP_OUT_START | addr; + } else { + /* + * Avoid setup time issue by adding 1 NOP when number of bytes + * are more than FIFO/BLOCK size. setup time issue can't appear + * otherwise since next byte to be written will always be ready + */ + val = (QUP_OUT_NOP | 1); + } + + entries = qup->cnt + 1; + + if (entries > qup->chunk_sz) + entries = qup->chunk_sz; + + qup_tag = QUP_OUT_DATA; + + /* Reserve one entry for STOP */ + for (idx = 1; idx < (entries - 1); idx++, qup->pos++) { + + if (idx & 1) { + val |= (qup_tag | msg->buf[qup->pos]) << QUP_MSW_SHIFT; + writel(val, qup->base + QUP_OUT_FIFO_BASE); + } else { + val = qup_tag | msg->buf[qup->pos]; + } + } + + if (qup->pos == (msg->len - 1)) + qup_tag = QUP_OUT_STOP; + + if (idx & 1) + val |= (qup_tag | msg->buf[qup->pos]) << QUP_MSW_SHIFT; + else + val = qup_tag | msg->buf[qup->pos]; + + writel(val, qup->base + QUP_OUT_FIFO_BASE); + + qup->pos++; + qup->cnt = msg->len - qup->pos; +} + +static int qup_i2c_write_one(struct qup_i2c_dev *qup, struct i2c_msg *msg) +{ + unsigned long left; + bool block; + int ret; + + if (!msg->len) + return -EINVAL; + + qup->msg = msg; + qup->cnt = msg->len; + + qup->chunk_sz = qup->out_fifo_sz; + qup->bus_err = 0; + qup->qup_err = 0; + qup->pos = 0; + + enable_irq(qup->irq); + + block = qup_i2c_set_write_mode(qup, msg); + + INIT_COMPLETION(qup->xfer); + ret = qup_i2c_change_state(qup, QUP_RUN_STATE); + if (ret < 0) + goto err; + + writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL); + + if (block) { + /* Don't fill block till we get interrupt */ + qup->chunk_sz = qup->out_blk_sz; + left = wait_for_completion_timeout(&qup->xfer, qup->xfer_time); + if (!left) { + writel(1, qup->base + QUP_SW_RESET); + ret = -ETIMEDOUT; + goto err; + } + } + + do { + /* Note: transition to PAUSE state only possible from RUN */ + ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE); + if (ret < 0) + goto err; + + qup_i2c_issue_write(qup, msg); + + INIT_COMPLETION(qup->xfer); + ret = qup_i2c_change_state(qup, QUP_RUN_STATE); + if (ret < 0) + goto err; + + left = wait_for_completion_timeout(&qup->xfer, qup->xfer_time); + if (!left) { + writel(1, qup->base + QUP_SW_RESET); + ret = -ETIMEDOUT; + goto err; + } + + if (qup->bus_err || qup->qup_err) { + if (qup->bus_err & QUP_I2C_NACK_FLAG) + dev_err(qup->dev, "NACK from %x\n", msg->addr); + ret = -EIO; + goto err; + } + } while (qup->cnt > 0); + + err: + disable_irq(qup->irq); + qup->msg = NULL; + + qup_i2c_wait_clock_ready(qup); + + ret = qup_i2c_change_state(qup, QUP_RESET_STATE); + if (!ret) + ret = qup_i2c_wait_idle(qup, msg); + + return ret; +} + +static int qup_i2c_read_one(struct qup_i2c_dev *qup, struct i2c_msg *msg) +{ + unsigned long left; + int ret; + + if (!msg->len) + return -EINVAL; + + qup->cnt = msg->len; + qup->msg = msg; + + qup->chunk_sz = qup->in_fifo_sz; + qup->bus_err = 0; + qup->qup_err = 0; + qup->pos = 0; + + enable_irq(qup->irq); + + do { + qup_i2c_set_read_mode(qup); + + INIT_COMPLETION(qup->xfer); + ret = qup_i2c_change_state(qup, QUP_RUN_STATE); + if (ret < 0) + goto err; + + writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL); + + /* Note: transition to PAUSE state only possible from RUN */ + ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE); + if (ret < 0) + goto err; + + /* + * HW limits READ up to QUP_READ_LIMIT bytes in 1 + * read without stop + */ + qup_i2c_issue_read(qup, msg); + + ret = qup_i2c_change_state(qup, QUP_RUN_STATE); + if (ret < 0) + goto err; + + left = wait_for_completion_timeout(&qup->xfer, qup->xfer_time); + if (!left) { + writel(1, qup->base + QUP_SW_RESET); + ret = -ETIMEDOUT; + goto err; + } + + if (qup->bus_err || qup->qup_err) { + if (qup->bus_err & QUP_I2C_NACK_FLAG) + dev_err(qup->dev, "NACK from %x\n", msg->addr); + ret = -EIO; + goto err; + } + + qup_i2c_read_fifo(qup, msg); + } while (qup->cnt > 0); + + err: + disable_irq(qup->irq); + qup->msg = NULL; + + ret = qup_i2c_change_state(qup, QUP_RESET_STATE); + if (!ret) + ret = qup_i2c_wait_idle(qup, msg); + + return ret; +} + +/* + * Prepare controller for a transaction and call omap_i2c_xfer_msg + * to do the work during IRQ processing. + */ +static int +qup_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) +{ + struct qup_i2c_dev *qup = i2c_get_adapdata(adap); + int ret, idx; + + ret = pm_runtime_get_sync(qup->dev); + if (IS_ERR_VALUE(ret)) + goto out; + + writel(1, qup->base + QUP_SW_RESET); + ret = qup_i2c_poll_state(qup, QUP_RESET_STATE, false); + if (ret) { + dev_err(qup->dev, "cannot goto reset state\n"); + goto out; + } + + /* Initialize QUP registers */ + writel(0, qup->base + QUP_CONFIG); + writel(QUP_OPERATIONAL_RESET, qup->base + QUP_OPERATIONAL); + writel(QUP_STATUS_ERROR_FLAGS, qup->base + QUP_ERROR_FLAGS_EN); + writel(I2C_MINI_CORE | I2C_N_VAL, qup->base + QUP_CONFIG); + + /* Initialize I2C mini core registers */ + writel(0, qup->base + QUP_I2C_CLK_CTL); + writel(QUP_I2C_STATUS_RESET, qup->base + QUP_I2C_STATUS); + + for (idx = 0; idx < num; idx++) { + + if (qup_i2c_poll_state(qup, QUP_I2C_MAST_GEN, false) != 0) { + ret = -EIO; + goto out; + } + + if (msgs[idx].flags & I2C_M_RD) + ret = qup_i2c_read_one(qup, &msgs[idx]); + else + ret = qup_i2c_write_one(qup, &msgs[idx]); + + if (ret) + break; + } + + if (ret == 0) + ret = num; +out: + pm_runtime_mark_last_busy(qup->dev); + pm_runtime_put_autosuspend(qup->dev); + return ret; +} + +static u32 qup_i2c_func(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK); +} + +static const struct i2c_algorithm qup_i2c_algo = { + .master_xfer = qup_i2c_xfer, + .functionality = qup_i2c_func, +}; + +static int qup_i2c_probe(struct platform_device *pdev) +{ + struct device_node *node = pdev->dev.of_node; + struct qup_i2c_dev *qup; + struct resource *res; + u32 val, io_mode, hw_ver, size; + int ret, fs_div, hs_div; + + qup = devm_kzalloc(&pdev->dev, sizeof(*qup), GFP_KERNEL); + if (!qup) + return -ENOMEM; + + platform_set_drvdata(pdev, qup); + + ret = of_alias_get_id(node, "i2c"); + if (ret >= 0) + pdev->id = ret; + + qup->dev = &pdev->dev; + + qup->pctrl = devm_pinctrl_get_select_default(qup->dev); + if (IS_ERR(qup->pctrl)) { + dev_err(qup->dev, "failed to request pinctrl\n"); + return PTR_ERR(qup->pctrl); + } + + qup->clk_freq = 100000; + if (!of_property_read_u32(node, "clock-frequency", &val)) + qup->clk_freq = val; + + qup->src_clk_freq = DEFAULT_CLK_RATE; + if (!of_property_read_u32(node, "qcom,src-freq", &val)) + qup->src_clk_freq = val; + + /* We support frequencies up to FAST Mode(400KHz) */ + if (qup->clk_freq <= 0 || qup->clk_freq > 400000) { + dev_err(qup->dev, "clock frequency not supported %d\n", + qup->clk_freq); + return -EIO; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + qup->base = devm_ioremap_resource(qup->dev, res); + if (IS_ERR(qup->base)) + return PTR_ERR(qup->base); + + qup->irq = platform_get_irq(pdev, 0); + if (qup->irq < 0) { + dev_err(qup->dev, "No IRQ defined\n"); + return qup->irq; + } + + qup->clk = devm_clk_get(qup->dev, "core"); + if (IS_ERR(qup->clk)) { + dev_err(qup->dev, "Could not get core clock\n"); + return PTR_ERR(qup->clk); + } + + qup->pclk = devm_clk_get(qup->dev, "iface"); + if (IS_ERR(qup->pclk)) { + dev_err(qup->dev, "Could not get iface clock\n"); + return PTR_ERR(qup->pclk); + } + + ret = devm_request_irq(qup->dev, qup->irq, qup_i2c_interrupt, + IRQF_TRIGGER_HIGH, "i2c_qup", qup); + if (ret) { + dev_err(qup->dev, "Request %d IRQ failed\n", qup->irq); + return ret; + } + + disable_irq(qup->irq); + + init_completion(&qup->xfer); + + ret = clk_set_rate(qup->clk, qup->src_clk_freq); + if (ret) + dev_info(qup->dev, "Fail to set core clk, %dHz:%d\n", + qup->src_clk_freq, ret); + + qup_i2c_enable(qup, true); + + /* + * If bootloaders leave a pending interrupt on certain QUP's, + * then we reset the core before registering for interrupts. + */ + writel(1, qup->base + QUP_SW_RESET); + ret = qup_i2c_poll_state(qup, 0, true); + if (ret) + goto fail; + + hw_ver = readl(qup->base + QUP_HW_VERSION); + dev_dbg(qup->dev, "%d Revision %x\n", pdev->id, hw_ver); + + fs_div = ((qup->src_clk_freq / qup->clk_freq) / 2) - 3; + hs_div = 3; + qup->clk_ctl = (hs_div << 8) | (fs_div & 0xff); + qup->one_bit_t = (USEC_PER_SEC / qup->clk_freq) + 1; + + io_mode = readl(qup->base + QUP_IO_MODE); + + size = QUP_OUTPUT_BLOCK_SIZE(io_mode); + if (size) + qup->out_blk_sz = size * 16; + else + qup->out_blk_sz = 16; + + size = QUP_INPUT_BLOCK_SIZE(io_mode); + if (size) + qup->in_blk_sz = size * 16; + else + qup->in_blk_sz = 16; + + qup->xfer_time = msecs_to_jiffies(qup->out_fifo_sz); + + /* + * The block/fifo size w.r.t. 'actual data' is 1/2 due to 'tag' + * associated with each byte written/received + */ + qup->out_blk_sz /= 2; + qup->in_blk_sz /= 2; + + size = QUP_OUTPUT_FIFO_SIZE(io_mode); + qup->out_fifo_sz = qup->out_blk_sz * (2 << size); + + size = QUP_INPUT_FIFO_SIZE(io_mode); + qup->in_fifo_sz = qup->in_blk_sz * (2 << size); + + /* + * Wait for FIFO number of bytes to be absolutely sure + * that I2C write state machine is not idle. Each byte + * takes 9 clock cycles. (8 bits + 1 ack) + */ + qup->wait_idle = qup->one_bit_t * 9; + qup->wait_idle *= qup->out_fifo_sz; + + dev_info(qup->dev, "IN:block:%d, fifo:%d, OUT:block:%d, fifo:%d\n", + qup->in_blk_sz, qup->in_fifo_sz, + qup->out_blk_sz, qup->out_fifo_sz); + + i2c_set_adapdata(&qup->adap, qup); + qup->adap.algo = &qup_i2c_algo; + qup->adap.nr = pdev->id; + qup->adap.dev.parent = qup->dev; + qup->adap.dev.of_node = pdev->dev.of_node; + strlcpy(qup->adap.name, "QUP I2C adapter", sizeof(qup->adap.name)); + + ret = i2c_add_numbered_adapter(&qup->adap); + if (!ret) { + of_i2c_register_devices(&qup->adap); + pm_runtime_set_autosuspend_delay(qup->dev, MSEC_PER_SEC); + pm_runtime_use_autosuspend(qup->dev); + pm_runtime_enable(qup->dev); + return 0; + } +fail: + qup_i2c_enable(qup, false); + return ret; +} + +static int qup_i2c_remove(struct platform_device *pdev) +{ + struct qup_i2c_dev *qup = platform_get_drvdata(pdev); + + disable_irq(qup->irq); + qup_i2c_enable(qup, false); + i2c_del_adapter(&qup->adap); + pm_runtime_disable(qup->dev); + pm_runtime_set_suspended(qup->dev); + return 0; +} + +#ifdef CONFIG_PM +static int qup_i2c_pm_suspend_runtime(struct device *device) +{ + struct qup_i2c_dev *qup = dev_get_drvdata(device); + + dev_dbg(device, "pm_runtime: suspending...\n"); + qup_i2c_enable(qup, false); + return 0; +} + +static int qup_i2c_pm_resume_runtime(struct device *device) +{ + struct qup_i2c_dev *qup = dev_get_drvdata(device); + + dev_dbg(device, "pm_runtime: resuming...\n"); + qup_i2c_enable(qup, true); + return 0; +} + +static int qup_i2c_suspend(struct device *device) +{ + dev_dbg(device, "system suspend"); + qup_i2c_pm_suspend_runtime(device); + return 0; +} + +static int qup_i2c_resume(struct device *device) +{ + dev_dbg(device, "system resume"); + qup_i2c_pm_resume_runtime(device); + pm_runtime_mark_last_busy(device); + pm_request_autosuspend(device); + return 0; +} +#endif /* CONFIG_PM */ + +static const struct dev_pm_ops qup_i2c_qup_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS( + qup_i2c_suspend, + qup_i2c_resume) + SET_RUNTIME_PM_OPS( + qup_i2c_pm_suspend_runtime, + qup_i2c_pm_resume_runtime, + NULL) +}; + +static struct of_device_id qup_i2c_dt_match[] = { + {.compatible = "qcom,i2c-qup"}, + {} +}; + +static struct platform_driver qup_i2c_driver = { + .probe = qup_i2c_probe, + .remove = qup_i2c_remove, + .driver = { + .name = "i2c_qup", + .owner = THIS_MODULE, + .pm = &qup_i2c_qup_pm_ops, + .of_match_table = qup_i2c_dt_match, + }, +}; + +module_platform_driver(qup_i2c_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:i2c_qup");