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Message-ID: <1389999819-10648-3-git-send-email-bjorn.andersson@sonymobile.com>
Date: Fri, 17 Jan 2014 15:03:39 -0800
From: Bjorn Andersson <bjorn.andersson@...ymobile.com>
To: Rob Herring <rob.herring@...xeda.com>,
Pawel Moll <pawel.moll@....com>,
Mark Rutland <mark.rutland@....com>,
Ian Campbell <ijc+devicetree@...lion.org.uk>,
Kumar Gala <galak@...eaurora.org>,
Rob Landley <rob@...dley.net>,
Wolfram Sang <wsa@...-dreams.de>,
Grant Likely <grant.likely@...aro.org>,
Bjorn Andersson <bjorn.andersson@...ymobile.com>,
"Ivan T. Ivanov" <iivanov@...sol.com>,
Jean Delvare <khali@...ux-fr.org>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Martin Schwidefsky <schwidefsky@...ibm.com>,
James Ralston <james.d.ralston@...el.com>,
Bill Brown <bill.e.brown@...el.com>,
Matt Porter <matt.porter@...aro.org>,
Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
<devicetree@...r.kernel.org>, <linux-doc@...r.kernel.org>,
<linux-kernel@...r.kernel.org>, <linux-i2c@...r.kernel.org>,
<linux-arm-kernel@...ts.infradead.org>,
<linux-arm-msm@...r.kernel.org>
Subject: [PATCH v3 2/2] i2c: New bus driver for the QUP I2C controller
From: "Ivan T. Ivanov" <iivanov@...sol.com>
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.
Signed-off-by: Ivan T. Ivanov <iivanov@...sol.com>
[bjorn: updated to reflect i2c framework changes
splited up qup_i2c_enable() in enable/disable
don't overwrite ret value on error in xfer functions
initilize core for each transfer
remove explicit pinctrl selection
use existing clock instead of setting new core clock]
Signed-off-by: Bjorn Andersson <bjorn.andersson@...ymobile.com>
---
drivers/i2c/busses/Kconfig | 10 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-qup.c | 894 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 905 insertions(+)
create mode 100644 drivers/i2c/busses/i2c-qup.c
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 3b26129..4eaded0 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -648,6 +648,16 @@ config I2C_PXA_SLAVE
is necessary for systems where the PXA may be a target on the
I2C bus.
+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.
+
config HAVE_S3C2410_I2C
bool
help
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index c73eb0e..c93f593 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -63,6 +63,7 @@ obj-$(CONFIG_I2C_PNX) += i2c-pnx.o
obj-$(CONFIG_I2C_PUV3) += i2c-puv3.o
obj-$(CONFIG_I2C_PXA) += i2c-pxa.o
obj-$(CONFIG_I2C_PXA_PCI) += i2c-pxa-pci.o
+obj-$(CONFIG_I2C_QUP) += i2c-qup.o
obj-$(CONFIG_I2C_S3C2410) += i2c-s3c2410.o
obj-$(CONFIG_I2C_S6000) += i2c-s6000.o
obj-$(CONFIG_I2C_SH7760) += i2c-sh7760.o
diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
new file mode 100644
index 0000000..2e0020e
--- /dev/null
+++ b/drivers/i2c/busses/i2c-qup.c
@@ -0,0 +1,894 @@
+/* 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.
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+/* 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 BIT(10)
+#define QUP_INPUT_BLK_MODE BIT(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 QUP_MAX_QUP_STATE_RETRIES 100
+#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;
+ int irq;
+ struct clk *clk;
+ struct clk *pclk;
+ struct i2c_adapter adap;
+
+ 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 posion 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 iteration). 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) {
+ if ((opflags & QUP_MX_INPUT_DONE) || (opflags & QUP_IN_SVC_FLAG))
+ writel(QUP_IN_SVC_FLAG, qup->base + QUP_OPERATIONAL);
+ else
+ return IRQ_HANDLED;
+ }
+
+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;
+ }
+
+ udelay(1);
+ } while (retries++ != QUP_MAX_QUP_STATE_RETRIES);
+
+ 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_clocks(struct qup_i2c_dev *qup)
+{
+ clk_prepare_enable(qup->clk);
+ clk_prepare_enable(qup->pclk);
+}
+
+static void qup_i2c_disable_clocks(struct qup_i2c_dev *qup)
+{
+ u32 config;
+
+ 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;
+ int tmp;
+
+ 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);
+
+ reinit_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);
+
+ reinit_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);
+
+ tmp = qup_i2c_change_state(qup, QUP_RESET_STATE);
+ if (!tmp)
+ tmp = qup_i2c_wait_idle(qup, msg);
+ if (!ret)
+ ret = tmp;
+
+ return ret;
+}
+
+static int qup_i2c_read_one(struct qup_i2c_dev *qup, struct i2c_msg *msg)
+{
+ unsigned long left;
+ int ret;
+ int tmp;
+
+ 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);
+
+ reinit_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;
+
+ tmp = qup_i2c_change_state(qup, QUP_RESET_STATE);
+ if (!tmp)
+ tmp = qup_i2c_wait_idle(qup, msg);
+ if (!ret)
+ ret = tmp;
+
+ 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;
+ }
+
+ for (idx = 0; idx < num; idx++) {
+ /* 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);
+
+ 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;
+ int src_clk_freq;
+ int clk_freq;
+
+ 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;
+
+ clk_freq = 100000;
+ if (!of_property_read_u32(node, "clock-frequency", &val))
+ clk_freq = val;
+
+ /* We support frequencies up to FAST Mode(400KHz) */
+ if (clk_freq <= 0 || clk_freq > 400000) {
+ dev_err(qup->dev, "clock frequency not supported %d\n",
+ 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);
+ }
+
+ init_completion(&qup->xfer);
+
+ qup_i2c_enable_clocks(qup);
+
+ /*
+ * Bootloaders might leave a pending interrupt on certain QUP's,
+ * so 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;
+
+ 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);
+ goto fail;
+ }
+ disable_irq(qup->irq);
+
+ hw_ver = readl(qup->base + QUP_HW_VERSION);
+ dev_dbg(qup->dev, "%d Revision %x\n", pdev->id, hw_ver);
+
+ src_clk_freq = clk_get_rate(qup->clk);
+ fs_div = ((src_clk_freq / clk_freq) / 2) - 3;
+ hs_div = 3;
+ qup->clk_ctl = (hs_div << 8) | (fs_div & 0xff);
+ qup->one_bit_t = (USEC_PER_SEC / 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) {
+ 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_disable_clocks(qup);
+ 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_disable_clocks(qup);
+ 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_disable_clocks(qup);
+ 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_clocks(qup);
+ return 0;
+}
+#endif
+
+#ifdef CONFIG_PM_SLEEP
+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
+
+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 const struct of_device_id qup_i2c_dt_match[] = {
+ {.compatible = "qcom,i2c-qup"},
+ {}
+};
+MODULE_DEVICE_TABLE(of, qup_i2c_dt_match);
+
+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");
--
1.8.2.2
--
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