[PATCH RFC 5/7] i2c: i2c-qcom-geni: Add bus driver for the Qualcomm GENI I2C controller

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This bus driver supports the GENI based i2c hardware controller in the
Qualcomm SOCs. The Qualcomm Generic Interface (GENI) is a programmable
module supporting a wide range of serial interfaces including I2C. The
driver supports FIFO mode and DMA mode of transfer and switches modes
dynamically depending on the size of the transfer.

Signed-off-by: Karthikeyan Ramasubramanian <kramasub@xxxxxxxxxxxxxx>
Signed-off-by: Sagar Dharia <sdharia@xxxxxxxxxxxxxx>
Signed-off-by: Girish Mahadevan <girishm@xxxxxxxxxxxxxx>
---
 drivers/i2c/busses/Kconfig         |  10 +
 drivers/i2c/busses/Makefile        |   1 +
 drivers/i2c/busses/i2c-qcom-geni.c | 685 +++++++++++++++++++++++++++++++++++++
 3 files changed, 696 insertions(+)
 create mode 100644 drivers/i2c/busses/i2c-qcom-geni.c

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 009345d..caef309 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -838,6 +838,16 @@ config I2C_PXA_SLAVE
 	  is necessary for systems where the PXA may be a target on the
 	  I2C bus.
 
+config I2C_QCOM_GENI
+	tristate "Qualcomm Technologies Inc.'s GENI based I2C controller"
+	depends on ARCH_QCOM
+	help
+	  If you say yes to this option, support will be included for the
+	  built-in I2C interface on the Qualcomm Technologies Inc.'s SoCs.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called i2c-qcom-geni.
+
 config I2C_QUP
 	tristate "Qualcomm QUP based I2C controller"
 	depends on ARCH_QCOM
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 2ce8576..201fce1 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -84,6 +84,7 @@ 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-$(CONFIG_I2C_QCOM_GENI)	+= i2c-qcom-geni.o
 obj-$(CONFIG_I2C_QUP)		+= i2c-qup.o
 obj-$(CONFIG_I2C_RIIC)		+= i2c-riic.o
 obj-$(CONFIG_I2C_RK3X)		+= i2c-rk3x.o
diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
new file mode 100644
index 0000000..6ffe17e
--- /dev/null
+++ b/drivers/i2c/busses/i2c-qcom-geni.c
@@ -0,0 +1,685 @@
+/*
+ * Copyright (c) 2017, 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/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/dma-mapping.h>
+#include <linux/qcom-geni-se.h>
+
+#define SE_I2C_TX_TRANS_LEN		(0x26C)
+#define SE_I2C_RX_TRANS_LEN		(0x270)
+#define SE_I2C_SCL_COUNTERS		(0x278)
+#define SE_GENI_IOS			(0x908)
+
+#define SE_I2C_ERR  (M_CMD_OVERRUN_EN | M_ILLEGAL_CMD_EN | M_CMD_FAILURE_EN |\
+			M_GP_IRQ_1_EN | M_GP_IRQ_3_EN | M_GP_IRQ_4_EN)
+#define SE_I2C_ABORT (1U << 1)
+/* M_CMD OP codes for I2C */
+#define I2C_WRITE		(0x1)
+#define I2C_READ		(0x2)
+#define I2C_WRITE_READ		(0x3)
+#define I2C_ADDR_ONLY		(0x4)
+#define I2C_BUS_CLEAR		(0x6)
+#define I2C_STOP_ON_BUS		(0x7)
+/* M_CMD params for I2C */
+#define PRE_CMD_DELAY		(BIT(0))
+#define TIMESTAMP_BEFORE	(BIT(1))
+#define STOP_STRETCH		(BIT(2))
+#define TIMESTAMP_AFTER		(BIT(3))
+#define POST_COMMAND_DELAY	(BIT(4))
+#define IGNORE_ADD_NACK		(BIT(6))
+#define READ_FINISHED_WITH_ACK	(BIT(7))
+#define BYPASS_ADDR_PHASE	(BIT(8))
+#define SLV_ADDR_MSK		(GENMASK(15, 9))
+#define SLV_ADDR_SHFT		(9)
+
+#define I2C_CORE2X_VOTE		(10000)
+#define GP_IRQ0			0
+#define GP_IRQ1			1
+#define GP_IRQ2			2
+#define GP_IRQ3			3
+#define GP_IRQ4			4
+#define GP_IRQ5			5
+#define GENI_OVERRUN		6
+#define GENI_ILLEGAL_CMD	7
+#define GENI_ABORT_DONE		8
+#define GENI_TIMEOUT		9
+
+#define I2C_NACK		GP_IRQ1
+#define I2C_BUS_PROTO		GP_IRQ3
+#define I2C_ARB_LOST		GP_IRQ4
+#define DM_I2C_CB_ERR		((BIT(GP_IRQ1) | BIT(GP_IRQ3) | BIT(GP_IRQ4)) \
+									<< 5)
+
+#define I2C_AUTO_SUSPEND_DELAY	250
+#define KHz(freq)		(1000 * freq)
+
+struct geni_i2c_dev {
+	struct device *dev;
+	void __iomem *base;
+	unsigned int tx_wm;
+	int irq;
+	int err;
+	struct i2c_adapter adap;
+	struct completion xfer;
+	struct i2c_msg *cur;
+	struct geni_se_rsc i2c_rsc;
+	int cur_wr;
+	int cur_rd;
+	struct device *wrapper_dev;
+	u32 clk_freq_out;
+	int clk_fld_idx;
+};
+
+struct geni_i2c_err_log {
+	int err;
+	const char *msg;
+};
+
+static struct geni_i2c_err_log gi2c_log[] = {
+	[GP_IRQ0] = {-EINVAL, "Unknown I2C err GP_IRQ0"},
+	[I2C_NACK] = {-ENOTCONN,
+			"NACK: slv unresponsive, check its power/reset-ln"},
+	[GP_IRQ2] = {-EINVAL, "Unknown I2C err GP IRQ2"},
+	[I2C_BUS_PROTO] = {-EPROTO,
+				"Bus proto err, noisy/unepxected start/stop"},
+	[I2C_ARB_LOST] = {-EBUSY,
+				"Bus arbitration lost, clock line undriveable"},
+	[GP_IRQ5] = {-EINVAL, "Unknown I2C err GP IRQ5"},
+	[GENI_OVERRUN] = {-EIO, "Cmd overrun, check GENI cmd-state machine"},
+	[GENI_ILLEGAL_CMD] = {-EILSEQ,
+				"Illegal cmd, check GENI cmd-state machine"},
+	[GENI_ABORT_DONE] = {-ETIMEDOUT, "Abort after timeout successful"},
+	[GENI_TIMEOUT] = {-ETIMEDOUT, "I2C TXN timed out"},
+};
+
+struct geni_i2c_clk_fld {
+	u32	clk_freq_out;
+	u8	clk_div;
+	u8	t_high;
+	u8	t_low;
+	u8	t_cycle;
+};
+
+static struct geni_i2c_clk_fld geni_i2c_clk_map[] = {
+	{KHz(100), 7, 10, 11, 26},
+	{KHz(400), 2,  5, 12, 24},
+	{KHz(1000), 1, 3,  9, 18},
+};
+
+static int geni_i2c_clk_map_idx(struct geni_i2c_dev *gi2c)
+{
+	int i;
+	int ret = 0;
+	bool clk_map_present = false;
+	struct geni_i2c_clk_fld *itr = geni_i2c_clk_map;
+
+	for (i = 0; i < ARRAY_SIZE(geni_i2c_clk_map); i++, itr++) {
+		if (itr->clk_freq_out == gi2c->clk_freq_out) {
+			clk_map_present = true;
+			break;
+		}
+	}
+
+	if (clk_map_present)
+		gi2c->clk_fld_idx = i;
+	else
+		ret = -EINVAL;
+
+	return ret;
+}
+
+static inline void qcom_geni_i2c_conf(struct geni_i2c_dev *gi2c, int dfs)
+{
+	struct geni_i2c_clk_fld *itr = geni_i2c_clk_map + gi2c->clk_fld_idx;
+
+	geni_write_reg(dfs, gi2c->base, SE_GENI_CLK_SEL);
+
+	geni_write_reg((itr->clk_div << 4) | 1, gi2c->base, GENI_SER_M_CLK_CFG);
+	geni_write_reg(((itr->t_high << 20) | (itr->t_low << 10) |
+			itr->t_cycle), gi2c->base, SE_I2C_SCL_COUNTERS);
+
+	/* Ensure Clk config completes before return */
+	mb();
+}
+
+static void geni_i2c_err(struct geni_i2c_dev *gi2c, int err)
+{
+	u32 m_cmd = readl_relaxed(gi2c->base + SE_GENI_M_CMD0);
+	u32 m_stat = readl_relaxed(gi2c->base + SE_GENI_M_IRQ_STATUS);
+	u32 geni_s = readl_relaxed(gi2c->base + SE_GENI_STATUS);
+	u32 geni_ios = readl_relaxed(gi2c->base + SE_GENI_IOS);
+	u32 dma = readl_relaxed(gi2c->base + SE_GENI_DMA_MODE_EN);
+	u32 rx_st, tx_st;
+
+	if (gi2c->cur)
+		dev_dbg(gi2c->dev, "len:%d, slv-addr:0x%x, RD/WR:%d\n",
+			gi2c->cur->len, gi2c->cur->addr, gi2c->cur->flags);
+
+	if (err == I2C_NACK || err == GENI_ABORT_DONE) {
+		dev_dbg(gi2c->dev, "%s\n", gi2c_log[err].msg);
+		goto err_ret;
+	} else {
+		dev_err(gi2c->dev, "%s\n", gi2c_log[err].msg);
+	}
+
+	if (dma) {
+		rx_st = readl_relaxed(gi2c->base + SE_DMA_RX_IRQ_STAT);
+		tx_st = readl_relaxed(gi2c->base + SE_DMA_TX_IRQ_STAT);
+	} else {
+		rx_st = readl_relaxed(gi2c->base + SE_GENI_RX_FIFO_STATUS);
+		tx_st = readl_relaxed(gi2c->base + SE_GENI_TX_FIFO_STATUS);
+	}
+	dev_dbg(gi2c->dev, "DMA:%d tx_stat:0x%x, rx_stat:0x%x, irq-stat:0x%x\n",
+		dma, tx_st, rx_st, m_stat);
+	dev_dbg(gi2c->dev, "m_cmd:0x%x, geni_status:0x%x, geni_ios:0x%x\n",
+		m_cmd, geni_s, geni_ios);
+err_ret:
+	gi2c->err = gi2c_log[err].err;
+}
+
+static irqreturn_t geni_i2c_irq(int irq, void *dev)
+{
+	struct geni_i2c_dev *gi2c = dev;
+	int i, j;
+	u32 m_stat = readl_relaxed(gi2c->base + SE_GENI_M_IRQ_STATUS);
+	u32 rx_st = readl_relaxed(gi2c->base + SE_GENI_RX_FIFO_STATUS);
+	u32 dm_tx_st = readl_relaxed(gi2c->base + SE_DMA_TX_IRQ_STAT);
+	u32 dm_rx_st = readl_relaxed(gi2c->base + SE_DMA_RX_IRQ_STAT);
+	u32 dma = readl_relaxed(gi2c->base + SE_GENI_DMA_MODE_EN);
+	struct i2c_msg *cur = gi2c->cur;
+
+	if (!cur || (m_stat & M_CMD_FAILURE_EN) ||
+		    (dm_rx_st & (DM_I2C_CB_ERR)) ||
+		    (m_stat & M_CMD_ABORT_EN)) {
+
+		if (m_stat & M_GP_IRQ_1_EN)
+			geni_i2c_err(gi2c, I2C_NACK);
+		if (m_stat & M_GP_IRQ_3_EN)
+			geni_i2c_err(gi2c, I2C_BUS_PROTO);
+		if (m_stat & M_GP_IRQ_4_EN)
+			geni_i2c_err(gi2c, I2C_ARB_LOST);
+		if (m_stat & M_CMD_OVERRUN_EN)
+			geni_i2c_err(gi2c, GENI_OVERRUN);
+		if (m_stat & M_ILLEGAL_CMD_EN)
+			geni_i2c_err(gi2c, GENI_ILLEGAL_CMD);
+		if (m_stat & M_CMD_ABORT_EN)
+			geni_i2c_err(gi2c, GENI_ABORT_DONE);
+		if (m_stat & M_GP_IRQ_0_EN)
+			geni_i2c_err(gi2c, GP_IRQ0);
+
+		if (!dma)
+			writel_relaxed(0, (gi2c->base +
+					   SE_GENI_TX_WATERMARK_REG));
+		goto irqret;
+	}
+
+	if (dma) {
+		dev_dbg(gi2c->dev, "i2c dma tx:0x%x, dma rx:0x%x\n", dm_tx_st,
+			dm_rx_st);
+		goto irqret;
+	}
+
+	if (((m_stat & M_RX_FIFO_WATERMARK_EN) ||
+		(m_stat & M_RX_FIFO_LAST_EN)) && (cur->flags & I2C_M_RD)) {
+		u32 rxcnt = rx_st & RX_FIFO_WC_MSK;
+
+		for (j = 0; j < rxcnt; j++) {
+			u32 temp;
+			int p;
+
+			temp = readl_relaxed(gi2c->base + SE_GENI_RX_FIFOn);
+			for (i = gi2c->cur_rd, p = 0; (i < cur->len && p < 4);
+				i++, p++)
+				cur->buf[i] = (u8) ((temp >> (p * 8)) & 0xff);
+			gi2c->cur_rd = i;
+			if (gi2c->cur_rd == cur->len) {
+				dev_dbg(gi2c->dev, "FIFO i:%d,read 0x%x\n",
+					i, temp);
+				break;
+			}
+		}
+	} else if ((m_stat & M_TX_FIFO_WATERMARK_EN) &&
+					!(cur->flags & I2C_M_RD)) {
+		for (j = 0; j < gi2c->tx_wm; j++) {
+			u32 temp = 0;
+			int p;
+
+			for (i = gi2c->cur_wr, p = 0; (i < cur->len && p < 4);
+				i++, p++)
+				temp |= (((u32)(cur->buf[i]) << (p * 8)));
+			writel_relaxed(temp, gi2c->base + SE_GENI_TX_FIFOn);
+			gi2c->cur_wr = i;
+			dev_dbg(gi2c->dev, "FIFO i:%d,wrote 0x%x\n", i, temp);
+			if (gi2c->cur_wr == cur->len) {
+				dev_dbg(gi2c->dev, "FIFO i2c bytes done writing\n");
+				writel_relaxed(0,
+				(gi2c->base + SE_GENI_TX_WATERMARK_REG));
+				break;
+			}
+		}
+	}
+irqret:
+	if (m_stat)
+		writel_relaxed(m_stat, gi2c->base + SE_GENI_M_IRQ_CLEAR);
+
+	if (dma) {
+		if (dm_tx_st)
+			writel_relaxed(dm_tx_st, gi2c->base +
+				       SE_DMA_TX_IRQ_CLR);
+		if (dm_rx_st)
+			writel_relaxed(dm_rx_st, gi2c->base +
+				       SE_DMA_RX_IRQ_CLR);
+		/* Ensure all writes are done before returning from ISR. */
+		wmb();
+	}
+	/* if this is err with done-bit not set, handle that thr' timeout. */
+	if (m_stat & M_CMD_DONE_EN)
+		complete(&gi2c->xfer);
+	else if ((dm_tx_st & TX_DMA_DONE) || (dm_rx_st & RX_DMA_DONE))
+		complete(&gi2c->xfer);
+
+	return IRQ_HANDLED;
+}
+
+static int geni_i2c_xfer(struct i2c_adapter *adap,
+			 struct i2c_msg msgs[],
+			 int num)
+{
+	struct geni_i2c_dev *gi2c = i2c_get_adapdata(adap);
+	int i, ret = 0, timeout = 0;
+
+	gi2c->err = 0;
+	gi2c->cur = &msgs[0];
+	reinit_completion(&gi2c->xfer);
+	ret = pm_runtime_get_sync(gi2c->dev);
+	if (ret < 0) {
+		dev_err(gi2c->dev, "error turning SE resources:%d\n", ret);
+		pm_runtime_put_noidle(gi2c->dev);
+		/* Set device in suspended since resume failed */
+		pm_runtime_set_suspended(gi2c->dev);
+		return ret;
+	}
+
+	qcom_geni_i2c_conf(gi2c, 0);
+	dev_dbg(gi2c->dev, "i2c xfer:num:%d, msgs:len:%d,flg:%d\n",
+				num, msgs[0].len, msgs[0].flags);
+	for (i = 0; i < num; i++) {
+		int stretch = (i < (num - 1));
+		u32 m_param = 0;
+		u32 m_cmd = 0;
+		dma_addr_t tx_dma = 0;
+		dma_addr_t rx_dma = 0;
+		enum geni_se_xfer_mode mode = FIFO_MODE;
+
+		m_param |= (stretch ? STOP_STRETCH : 0);
+		m_param |= ((msgs[i].addr & 0x7F) << SLV_ADDR_SHFT);
+
+		gi2c->cur = &msgs[i];
+		mode = msgs[i].len > 32 ? SE_DMA : FIFO_MODE;
+		ret = geni_se_select_mode(gi2c->base, mode);
+		if (ret) {
+			dev_err(gi2c->dev, "%s: Error mode init %d:%d:%d\n",
+				__func__, mode, i, msgs[i].len);
+			break;
+		}
+		if (msgs[i].flags & I2C_M_RD) {
+			dev_dbg(gi2c->dev,
+				"READ,n:%d,i:%d len:%d, stretch:%d\n",
+					num, i, msgs[i].len, stretch);
+			geni_write_reg(msgs[i].len,
+				       gi2c->base, SE_I2C_RX_TRANS_LEN);
+			m_cmd = I2C_READ;
+			geni_se_setup_m_cmd(gi2c->base, m_cmd, m_param);
+			if (mode == SE_DMA) {
+				ret = geni_se_rx_dma_prep(gi2c->wrapper_dev,
+							gi2c->base, msgs[i].buf,
+							msgs[i].len, &rx_dma);
+				if (ret) {
+					mode = FIFO_MODE;
+					ret = geni_se_select_mode(gi2c->base,
+								  mode);
+				}
+			}
+		} else {
+			dev_dbg(gi2c->dev,
+				"WRITE:n:%d,i:%d len:%d, stretch:%d, m_param:0x%x\n",
+					num, i, msgs[i].len, stretch, m_param);
+			geni_write_reg(msgs[i].len, gi2c->base,
+						SE_I2C_TX_TRANS_LEN);
+			m_cmd = I2C_WRITE;
+			geni_se_setup_m_cmd(gi2c->base, m_cmd, m_param);
+			if (mode == SE_DMA) {
+				ret = geni_se_tx_dma_prep(gi2c->wrapper_dev,
+							gi2c->base, msgs[i].buf,
+							msgs[i].len, &tx_dma);
+				if (ret) {
+					mode = FIFO_MODE;
+					ret = geni_se_select_mode(gi2c->base,
+								  mode);
+				}
+			}
+			if (mode == FIFO_MODE) /* Get FIFO IRQ */
+				geni_write_reg(1, gi2c->base,
+						SE_GENI_TX_WATERMARK_REG);
+		}
+		/* Ensure FIFO write go through before waiting for Done evet */
+		mb();
+		timeout = wait_for_completion_timeout(&gi2c->xfer, HZ);
+		if (!timeout) {
+			geni_i2c_err(gi2c, GENI_TIMEOUT);
+			gi2c->cur = NULL;
+			geni_se_abort_m_cmd(gi2c->base);
+			timeout = wait_for_completion_timeout(&gi2c->xfer, HZ);
+		}
+		gi2c->cur_wr = 0;
+		gi2c->cur_rd = 0;
+		if (mode == SE_DMA) {
+			if (gi2c->err) {
+				if (msgs[i].flags != I2C_M_RD)
+					writel_relaxed(1, gi2c->base +
+							SE_DMA_TX_FSM_RST);
+				else
+					writel_relaxed(1, gi2c->base +
+							SE_DMA_RX_FSM_RST);
+				wait_for_completion_timeout(&gi2c->xfer, HZ);
+			}
+			geni_se_rx_dma_unprep(gi2c->wrapper_dev, rx_dma,
+					      msgs[i].len);
+			geni_se_tx_dma_unprep(gi2c->wrapper_dev, tx_dma,
+					      msgs[i].len);
+		}
+		ret = gi2c->err;
+		if (gi2c->err) {
+			dev_err(gi2c->dev, "i2c error :%d\n", gi2c->err);
+			break;
+		}
+	}
+	if (ret == 0)
+		ret = num;
+
+	pm_runtime_mark_last_busy(gi2c->dev);
+	pm_runtime_put_autosuspend(gi2c->dev);
+	gi2c->cur = NULL;
+	gi2c->err = 0;
+	dev_dbg(gi2c->dev, "i2c txn ret:%d\n", ret);
+	return ret;
+}
+
+static u32 geni_i2c_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+}
+
+static const struct i2c_algorithm geni_i2c_algo = {
+	.master_xfer	= geni_i2c_xfer,
+	.functionality	= geni_i2c_func,
+};
+
+static int geni_i2c_probe(struct platform_device *pdev)
+{
+	struct geni_i2c_dev *gi2c;
+	struct resource *res;
+	struct platform_device *wrapper_pdev;
+	struct device_node *wrapper_ph_node;
+	int ret;
+
+	gi2c = devm_kzalloc(&pdev->dev, sizeof(*gi2c), GFP_KERNEL);
+	if (!gi2c)
+		return -ENOMEM;
+
+	gi2c->dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+
+	wrapper_ph_node = of_parse_phandle(pdev->dev.of_node,
+				"qcom,wrapper-core", 0);
+	if (IS_ERR_OR_NULL(wrapper_ph_node)) {
+		ret = PTR_ERR(wrapper_ph_node);
+		dev_err(&pdev->dev, "No wrapper core defined\n");
+		return ret;
+	}
+	wrapper_pdev = of_find_device_by_node(wrapper_ph_node);
+	of_node_put(wrapper_ph_node);
+	if (IS_ERR_OR_NULL(wrapper_pdev)) {
+		ret = PTR_ERR(wrapper_pdev);
+		dev_err(&pdev->dev, "Cannot retrieve wrapper device\n");
+		return ret;
+	}
+	gi2c->wrapper_dev = &wrapper_pdev->dev;
+	gi2c->i2c_rsc.wrapper_dev = &wrapper_pdev->dev;
+	gi2c->i2c_rsc.se_clk = devm_clk_get(&pdev->dev, "se-clk");
+	if (IS_ERR(gi2c->i2c_rsc.se_clk)) {
+		ret = PTR_ERR(gi2c->i2c_rsc.se_clk);
+		dev_err(&pdev->dev, "Err getting SE Core clk %d\n", ret);
+		return ret;
+	}
+
+	gi2c->i2c_rsc.m_ahb_clk = devm_clk_get(&pdev->dev, "m-ahb");
+	if (IS_ERR(gi2c->i2c_rsc.m_ahb_clk)) {
+		ret = PTR_ERR(gi2c->i2c_rsc.m_ahb_clk);
+		dev_err(&pdev->dev, "Err getting M AHB clk %d\n", ret);
+		return ret;
+	}
+
+	gi2c->i2c_rsc.s_ahb_clk = devm_clk_get(&pdev->dev, "s-ahb");
+	if (IS_ERR(gi2c->i2c_rsc.s_ahb_clk)) {
+		ret = PTR_ERR(gi2c->i2c_rsc.s_ahb_clk);
+		dev_err(&pdev->dev, "Err getting S AHB clk %d\n", ret);
+		return ret;
+	}
+
+	gi2c->base = devm_ioremap_resource(gi2c->dev, res);
+	if (IS_ERR(gi2c->base))
+		return PTR_ERR(gi2c->base);
+
+	gi2c->i2c_rsc.geni_pinctrl = devm_pinctrl_get(&pdev->dev);
+	if (IS_ERR_OR_NULL(gi2c->i2c_rsc.geni_pinctrl)) {
+		dev_err(&pdev->dev, "No pinctrl config specified\n");
+		ret = PTR_ERR(gi2c->i2c_rsc.geni_pinctrl);
+		return ret;
+	}
+	gi2c->i2c_rsc.geni_gpio_active =
+		pinctrl_lookup_state(gi2c->i2c_rsc.geni_pinctrl,
+							PINCTRL_DEFAULT);
+	if (IS_ERR_OR_NULL(gi2c->i2c_rsc.geni_gpio_active)) {
+		dev_err(&pdev->dev, "No default config specified\n");
+		ret = PTR_ERR(gi2c->i2c_rsc.geni_gpio_active);
+		return ret;
+	}
+	gi2c->i2c_rsc.geni_gpio_sleep =
+		pinctrl_lookup_state(gi2c->i2c_rsc.geni_pinctrl,
+							PINCTRL_SLEEP);
+	if (IS_ERR_OR_NULL(gi2c->i2c_rsc.geni_gpio_sleep)) {
+		dev_err(&pdev->dev, "No sleep config specified\n");
+		ret = PTR_ERR(gi2c->i2c_rsc.geni_gpio_sleep);
+		return ret;
+	}
+
+	if (of_property_read_u32(pdev->dev.of_node, "qcom,clk-freq-out",
+				&gi2c->clk_freq_out)) {
+		dev_info(&pdev->dev,
+			"Bus frequency not specified, default to 400KHz.\n");
+		gi2c->clk_freq_out = KHz(400);
+	}
+
+	gi2c->irq = platform_get_irq(pdev, 0);
+	if (gi2c->irq < 0) {
+		dev_err(gi2c->dev, "IRQ error for i2c-geni\n");
+		return gi2c->irq;
+	}
+
+	ret = geni_i2c_clk_map_idx(gi2c);
+	if (ret) {
+		dev_err(gi2c->dev, "Invalid clk frequency %d KHz: %d\n",
+				gi2c->clk_freq_out, ret);
+		return ret;
+	}
+
+	gi2c->adap.algo = &geni_i2c_algo;
+	init_completion(&gi2c->xfer);
+	platform_set_drvdata(pdev, gi2c);
+	ret = devm_request_irq(gi2c->dev, gi2c->irq, geni_i2c_irq,
+			       IRQF_TRIGGER_HIGH, "i2c_geni", gi2c);
+	if (ret) {
+		dev_err(gi2c->dev, "Request_irq failed:%d: err:%d\n",
+				   gi2c->irq, ret);
+		return ret;
+	}
+	disable_irq(gi2c->irq);
+	i2c_set_adapdata(&gi2c->adap, gi2c);
+	gi2c->adap.dev.parent = gi2c->dev;
+	gi2c->adap.dev.of_node = pdev->dev.of_node;
+
+	strlcpy(gi2c->adap.name, "Geni-I2C", sizeof(gi2c->adap.name));
+
+	pm_runtime_set_suspended(gi2c->dev);
+	pm_runtime_set_autosuspend_delay(gi2c->dev, I2C_AUTO_SUSPEND_DELAY);
+	pm_runtime_use_autosuspend(gi2c->dev);
+	pm_runtime_enable(gi2c->dev);
+	i2c_add_adapter(&gi2c->adap);
+
+	dev_dbg(gi2c->dev, "I2C probed\n");
+	return 0;
+}
+
+static int geni_i2c_remove(struct platform_device *pdev)
+{
+	struct geni_i2c_dev *gi2c = platform_get_drvdata(pdev);
+
+	pm_runtime_disable(gi2c->dev);
+	i2c_del_adapter(&gi2c->adap);
+	return 0;
+}
+
+static int geni_i2c_resume_noirq(struct device *device)
+{
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int geni_i2c_runtime_suspend(struct device *dev)
+{
+	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
+
+	disable_irq(gi2c->irq);
+	geni_se_resources_off(&gi2c->i2c_rsc);
+	return 0;
+}
+
+static int geni_i2c_runtime_resume(struct device *dev)
+{
+	int ret;
+	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
+
+	ret = geni_se_resources_on(&gi2c->i2c_rsc);
+	if (ret)
+		return ret;
+
+	if (!unlikely(gi2c->tx_wm)) {
+		int proto = geni_se_get_proto(gi2c->base);
+		int gi2c_tx_depth = geni_se_get_tx_fifo_depth(gi2c->base);
+
+		if (unlikely(proto != I2C)) {
+			dev_err(gi2c->dev, "Invalid proto %d\n", proto);
+			geni_se_resources_off(&gi2c->i2c_rsc);
+			return -ENXIO;
+		}
+
+		gi2c->tx_wm = gi2c_tx_depth - 1;
+		geni_se_init(gi2c->base, gi2c->tx_wm, gi2c_tx_depth);
+		geni_se_config_packing(gi2c->base, 8, 4, true);
+		dev_dbg(gi2c->dev, "i2c fifo/se-dma mode. fifo depth:%d\n",
+			gi2c_tx_depth);
+	}
+	enable_irq(gi2c->irq);
+
+	return 0;
+}
+
+static int geni_i2c_suspend_noirq(struct device *device)
+{
+	struct geni_i2c_dev *gi2c = dev_get_drvdata(device);
+	int ret;
+
+	/* Make sure no transactions are pending */
+	ret = i2c_trylock_bus(&gi2c->adap, I2C_LOCK_SEGMENT);
+	if (!ret) {
+		dev_err(gi2c->dev, "late I2C transaction request\n");
+		return -EBUSY;
+	}
+	if (!pm_runtime_status_suspended(device)) {
+		geni_i2c_runtime_suspend(device);
+		pm_runtime_disable(device);
+		pm_runtime_set_suspended(device);
+		pm_runtime_enable(device);
+	}
+	i2c_unlock_bus(&gi2c->adap, I2C_LOCK_SEGMENT);
+	return 0;
+}
+#else
+static int geni_i2c_runtime_suspend(struct device *dev)
+{
+	return 0;
+}
+
+static int geni_i2c_runtime_resume(struct device *dev)
+{
+	return 0;
+}
+
+static int geni_i2c_suspend_noirq(struct device *device)
+{
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops geni_i2c_pm_ops = {
+	.suspend_noirq		= geni_i2c_suspend_noirq,
+	.resume_noirq		= geni_i2c_resume_noirq,
+	.runtime_suspend	= geni_i2c_runtime_suspend,
+	.runtime_resume		= geni_i2c_runtime_resume,
+};
+
+static const struct of_device_id geni_i2c_dt_match[] = {
+	{ .compatible = "qcom,i2c-geni" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, geni_i2c_dt_match);
+
+static struct platform_driver geni_i2c_driver = {
+	.probe  = geni_i2c_probe,
+	.remove = geni_i2c_remove,
+	.driver = {
+		.name = "i2c_geni",
+		.pm = &geni_i2c_pm_ops,
+		.of_match_table = geni_i2c_dt_match,
+	},
+};
+
+module_platform_driver(geni_i2c_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:i2c_geni");
-- 
Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

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