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 <krama...@codeaurora.org>
Signed-off-by: Sagar Dharia <sdha...@codeaurora.org>
Signed-off-by: Girish Mahadevan <giri...@codeaurora.org>
---
 drivers/i2c/busses/Kconfig         |  11 +
 drivers/i2c/busses/Makefile        |   1 +
 drivers/i2c/busses/i2c-qcom-geni.c | 626 +++++++++++++++++++++++++++++++++++++
 3 files changed, 638 insertions(+)
 create mode 100644 drivers/i2c/busses/i2c-qcom-geni.c

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index e2954fb..1ddf5cd 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -848,6 +848,17 @@ 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
+       depends on QCOM_GENI_SE
+       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..e1e4268
--- /dev/null
+++ b/drivers/i2c/busses/i2c-qcom-geni.c
@@ -0,0 +1,626 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
+
+#include <linux/clk.h>
+#include <linux/dma-mapping.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/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_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           BIT(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
+/* I2C SCL COUNTER fields */
+#define HIGH_COUNTER_MSK       GENMASK(29, 20)
+#define HIGH_COUNTER_SHFT      20
+#define LOW_COUNTER_MSK                GENMASK(19, 10)
+#define LOW_COUNTER_SHFT       10
+#define CYCLE_COUNTER_MSK      GENMASK(9, 0)
+
+#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)
+#define PACKING_BYTES_PW       4
+
+struct geni_i2c_dev {
+       struct geni_se se;
+       u32 tx_wm;
+       int irq;
+       int err;
+       struct i2c_adapter adap;
+       struct completion done;
+       struct i2c_msg *cur;
+       int cur_wr;
+       int cur_rd;
+       u32 clk_freq_out;
+       const struct geni_i2c_clk_fld *clk_fld;
+};
+
+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 const 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;
+       const 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) {
+                       gi2c->clk_fld = geni_i2c_clk_map + i;
+                       return 0;
+               }
+       }
+       return -EINVAL;
+}
+
+static void qcom_geni_i2c_conf(struct geni_i2c_dev *gi2c)
+{
+       const struct geni_i2c_clk_fld *itr = gi2c->clk_fld;
+       u32 val;
+
+       writel_relaxed(0, gi2c->se.base + SE_GENI_CLK_SEL);
+
+       val = (itr->clk_div << CLK_DIV_SHFT) | SER_CLK_EN;
+       writel_relaxed(val, gi2c->se.base + GENI_SER_M_CLK_CFG);
+
+       val = itr->t_high << HIGH_COUNTER_SHFT;
+       val |= itr->t_low << LOW_COUNTER_SHFT;
+       val |= itr->t_cycle;
+       writel_relaxed(val, gi2c->se.base + SE_I2C_SCL_COUNTERS);
+       /*
+        * Ensure later writes/reads to serial engine register block is
+        * not reordered before this point.
+        */
+       mb();
+}
+
+static void geni_i2c_err_misc(struct geni_i2c_dev *gi2c)
+{
+       u32 m_cmd = readl_relaxed(gi2c->se.base + SE_GENI_M_CMD0);
+       u32 m_stat = readl_relaxed(gi2c->se.base + SE_GENI_M_IRQ_STATUS);
+       u32 geni_s = readl_relaxed(gi2c->se.base + SE_GENI_STATUS);
+       u32 geni_ios = readl_relaxed(gi2c->se.base + SE_GENI_IOS);
+       u32 dma = readl_relaxed(gi2c->se.base + SE_GENI_DMA_MODE_EN);
+       u32 rx_st, tx_st;
+
+       if (dma) {
+               rx_st = readl_relaxed(gi2c->se.base + SE_DMA_RX_IRQ_STAT);
+               tx_st = readl_relaxed(gi2c->se.base + SE_DMA_TX_IRQ_STAT);
+       } else {
+               rx_st = readl_relaxed(gi2c->se.base + SE_GENI_RX_FIFO_STATUS);
+               tx_st = readl_relaxed(gi2c->se.base + SE_GENI_TX_FIFO_STATUS);
+       }
+       dev_dbg(gi2c->se.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->se.dev, "m_cmd:0x%x, geni_status:0x%x, geni_ios:0x%x\n",
+               m_cmd, geni_s, geni_ios);
+}
+
+static void geni_i2c_err(struct geni_i2c_dev *gi2c, int err)
+{
+       gi2c->err = gi2c_log[err].err;
+       if (gi2c->cur)
+               dev_dbg(gi2c->se.dev, "len:%d, slv-addr:0x%x, RD/WR:%d\n",
+                       gi2c->cur->len, gi2c->cur->addr, gi2c->cur->flags);
+       dev_dbg(gi2c->se.dev, "%s\n", gi2c_log[err].msg);
+
+       if (err != I2C_NACK && err != GENI_ABORT_DONE)
+               geni_i2c_err_misc(gi2c);
+}
+
+static irqreturn_t geni_i2c_irq(int irq, void *dev)
+{
+       struct geni_i2c_dev *gi2c = dev;
+       int j;
+       u32 m_stat = readl_relaxed(gi2c->se.base + SE_GENI_M_IRQ_STATUS);
+       u32 rx_st = readl_relaxed(gi2c->se.base + SE_GENI_RX_FIFO_STATUS);
+       u32 dm_tx_st = readl_relaxed(gi2c->se.base + SE_DMA_TX_IRQ_STAT);
+       u32 dm_rx_st = readl_relaxed(gi2c->se.base + SE_DMA_RX_IRQ_STAT);
+       u32 dma = readl_relaxed(gi2c->se.base + SE_GENI_DMA_MODE_EN);
+       struct i2c_msg *cur = gi2c->cur;
+
+       if (!cur ||
+           m_stat & (M_CMD_FAILURE_EN | M_CMD_ABORT_EN) ||
+           dm_rx_st & (DM_I2C_CB_ERR)) {
+               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);
+
+               /* Disable the TX Watermark interrupt to stop TX */
+               if (!dma)
+                       writel_relaxed(0, gi2c->se.base +
+                                          SE_GENI_TX_WATERMARK_REG);
+               goto irqret;
+       }
+
+       if (dma) {
+               dev_dbg(gi2c->se.dev, "i2c dma tx:0x%x, dma rx:0x%x\n",
+                       dm_tx_st, dm_rx_st);
+               goto irqret;
+       }
+
+       if (cur->flags & I2C_M_RD &&
+           m_stat & (M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN)) {
+               u32 rxcnt = rx_st & RX_FIFO_WC_MSK;
+
+               for (j = 0; j < rxcnt; j++) {
+                       u32 val;
+                       int p = 0;
+
+                       val = readl_relaxed(gi2c->se.base + SE_GENI_RX_FIFOn);
+                       while (gi2c->cur_rd < cur->len && p < sizeof(val)) {
+                               cur->buf[gi2c->cur_rd++] = val & 0xff;
+                               val >>= 8;
+                               p++;
+                       }
+                       if (gi2c->cur_rd == cur->len)
+                               break;
+               }
+       } else if (!(cur->flags & I2C_M_RD) &&
+                  m_stat & M_TX_FIFO_WATERMARK_EN) {
+               for (j = 0; j < gi2c->tx_wm; j++) {
+                       u32 temp;
+                       u32 val = 0;
+                       int p = 0;
+
+                       while (gi2c->cur_wr < cur->len && p < sizeof(val)) {
+                               temp = (u32)cur->buf[gi2c->cur_wr++];
+                               val |= (temp << (p * 8));
+                               p++;
+                       }
+                       writel_relaxed(val, gi2c->se.base + SE_GENI_TX_FIFOn);
+                       /* TX Complete, Disable the TX Watermark interrupt */
+                       if (gi2c->cur_wr == cur->len) {
+                               writel_relaxed(0, gi2c->se.base +
+                                               SE_GENI_TX_WATERMARK_REG);
+                               break;
+                       }
+               }
+       }
+irqret:
+       if (m_stat)
+               writel_relaxed(m_stat, gi2c->se.base + SE_GENI_M_IRQ_CLEAR);
+
+       if (dma) {
+               if (dm_tx_st)
+                       writel_relaxed(dm_tx_st, gi2c->se.base +
+                                               SE_DMA_TX_IRQ_CLR);
+               if (dm_rx_st)
+                       writel_relaxed(dm_rx_st, gi2c->se.base +
+                                               SE_DMA_RX_IRQ_CLR);
+       }
+       /* if this is err with done-bit not set, handle that through timeout. */
+       if (m_stat & M_CMD_DONE_EN)
+               complete(&gi2c->done);
+       else if ((dm_tx_st & TX_DMA_DONE) || (dm_rx_st & RX_DMA_DONE))
+               complete(&gi2c->done);
+
+       return IRQ_HANDLED;
+}
+
+static void geni_i2c_abort_xfer(struct geni_i2c_dev *gi2c)
+{
+       u32 val;
+       unsigned long timeout = HZ;
+
+       geni_i2c_err(gi2c, GENI_TIMEOUT);
+       gi2c->cur = NULL;
+       geni_se_abort_m_cmd(&gi2c->se);
+       do {
+               timeout = wait_for_completion_timeout(&gi2c->done, timeout);
+               val = readl_relaxed(gi2c->se.base + SE_GENI_M_IRQ_STATUS);
+       } while (!(val & M_CMD_ABORT_EN) && timeout);
+}
+
+static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
+                               u32 m_param)
+{
+       dma_addr_t rx_dma;
+       enum geni_se_xfer_mode mode;
+       unsigned long timeout;
+
+       gi2c->cur = msg;
+       mode = msg->len > 32 ? GENI_SE_DMA : GENI_SE_FIFO;
+       geni_se_select_mode(&gi2c->se, mode);
+       writel_relaxed(msg->len, gi2c->se.base + SE_I2C_RX_TRANS_LEN);
+       geni_se_setup_m_cmd(&gi2c->se, I2C_READ, m_param);
+       if (mode == GENI_SE_DMA) {
+               rx_dma = geni_se_rx_dma_prep(&gi2c->se, msg->buf, msg->len);
+               if (!rx_dma) {
+                       mode = GENI_SE_FIFO;
+                       geni_se_select_mode(&gi2c->se, mode);
+               }
+       }
+
+       timeout = wait_for_completion_timeout(&gi2c->done, HZ);
+       if (!timeout)
+               geni_i2c_abort_xfer(gi2c);
+
+       gi2c->cur_rd = 0;
+       if (mode == GENI_SE_DMA) {
+               if (gi2c->err) {
+                       writel_relaxed(1, gi2c->se.base + SE_DMA_RX_FSM_RST);
+                       wait_for_completion_timeout(&gi2c->done, HZ);
+               }
+               geni_se_rx_dma_unprep(&gi2c->se, rx_dma, msg->len);
+       }
+       if (gi2c->err)
+               dev_err(gi2c->se.dev, "i2c error :%d\n", gi2c->err);
+       return gi2c->err;
+}
+
+static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
+                               u32 m_param)
+{
+       dma_addr_t tx_dma;
+       enum geni_se_xfer_mode mode;
+       unsigned long timeout;
+
+       gi2c->cur = msg;
+       mode = msg->len > 32 ? GENI_SE_DMA : GENI_SE_FIFO;
+       geni_se_select_mode(&gi2c->se, mode);
+       writel_relaxed(msg->len, gi2c->se.base + SE_I2C_TX_TRANS_LEN);
+       geni_se_setup_m_cmd(&gi2c->se, I2C_WRITE, m_param);
+       if (mode == GENI_SE_DMA) {
+               tx_dma = geni_se_tx_dma_prep(&gi2c->se, msg->buf, msg->len);
+               if (!tx_dma) {
+                       mode = GENI_SE_FIFO;
+                       geni_se_select_mode(&gi2c->se, mode);
+               }
+       }
+
+       if (mode == GENI_SE_FIFO) /* Get FIFO IRQ */
+               writel_relaxed(1, gi2c->se.base + SE_GENI_TX_WATERMARK_REG);
+
+       timeout = wait_for_completion_timeout(&gi2c->done, HZ);
+       if (!timeout)
+               geni_i2c_abort_xfer(gi2c);
+
+       gi2c->cur_wr = 0;
+       if (mode == GENI_SE_DMA) {
+               if (gi2c->err) {
+                       writel_relaxed(1, gi2c->se.base + SE_DMA_TX_FSM_RST);
+                       wait_for_completion_timeout(&gi2c->done, HZ);
+               }
+               geni_se_tx_dma_unprep(&gi2c->se, tx_dma, msg->len);
+       }
+       if (gi2c->err)
+               dev_err(gi2c->se.dev, "i2c error :%d\n", gi2c->err);
+       return gi2c->err;
+}
+
+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;
+
+       gi2c->err = 0;
+       reinit_completion(&gi2c->done);
+       ret = pm_runtime_get_sync(gi2c->se.dev);
+       if (ret < 0) {
+               dev_err(gi2c->se.dev, "error turning SE resources:%d\n", ret);
+               pm_runtime_put_noidle(gi2c->se.dev);
+               /* Set device in suspended since resume failed */
+               pm_runtime_set_suspended(gi2c->se.dev);
+               return ret;
+       }
+
+       qcom_geni_i2c_conf(gi2c);
+       for (i = 0; i < num; i++) {
+               u32 m_param = i < (num - 1) ? STOP_STRETCH : 0;
+
+               m_param |= ((msgs[i].addr << SLV_ADDR_SHFT) & SLV_ADDR_MSK);
+
+               if (msgs[i].flags & I2C_M_RD)
+                       ret = geni_i2c_rx_one_msg(gi2c, &msgs[i], m_param);
+               else
+                       ret = geni_i2c_tx_one_msg(gi2c, &msgs[i], m_param);
+
+               if (ret) {
+                       dev_err(gi2c->se.dev, "i2c error %d @ %d\n", ret, i);
+                       break;
+               }
+       }
+       if (ret == 0)
+               ret = num;
+
+       pm_runtime_mark_last_busy(gi2c->se.dev);
+       pm_runtime_put_autosuspend(gi2c->se.dev);
+       gi2c->cur = NULL;
+       gi2c->err = 0;
+       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;
+       u32 proto, tx_depth;
+       int ret;
+
+       gi2c = devm_kzalloc(&pdev->dev, sizeof(*gi2c), GFP_KERNEL);
+       if (!gi2c)
+               return -ENOMEM;
+
+       gi2c->se.dev = &pdev->dev;
+       gi2c->se.wrapper = dev_get_drvdata(pdev->dev.parent);
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       gi2c->se.base = devm_ioremap_resource(&pdev->dev, res);
+       if (IS_ERR(gi2c->se.base)) {
+               ret = PTR_ERR(gi2c->se.base);
+               dev_err(&pdev->dev, "Err IO Mapping register block %d\n", ret);
+               return ret;
+       }
+
+       gi2c->se.clk = devm_clk_get(&pdev->dev, "se");
+       if (IS_ERR(gi2c->se.clk)) {
+               ret = PTR_ERR(gi2c->se.clk);
+               dev_err(&pdev->dev, "Err getting SE Core clk %d\n", ret);
+               return ret;
+       }
+
+       ret = device_property_read_u32(&pdev->dev, "clock-frequency",
+                                                       &gi2c->clk_freq_out);
+       if (ret) {
+               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(&pdev->dev, "IRQ error for i2c-geni\n");
+               return gi2c->irq;
+       }
+
+       ret = geni_i2c_clk_map_idx(gi2c);
+       if (ret) {
+               dev_err(&pdev->dev, "Invalid clk frequency %d KHz: %d\n",
+                       gi2c->clk_freq_out, ret);
+               return ret;
+       }
+
+       gi2c->adap.algo = &geni_i2c_algo;
+       init_completion(&gi2c->done);
+       platform_set_drvdata(pdev, gi2c);
+       ret = devm_request_irq(&pdev->dev, gi2c->irq, geni_i2c_irq,
+                              IRQF_TRIGGER_HIGH, "i2c_geni", gi2c);
+       if (ret) {
+               dev_err(&pdev->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 = &pdev->dev;
+       gi2c->adap.dev.of_node = pdev->dev.of_node;
+       strlcpy(gi2c->adap.name, "Geni-I2C", sizeof(gi2c->adap.name));
+
+       ret = geni_se_resources_on(&gi2c->se);
+       if (ret) {
+               dev_err(&pdev->dev, "Error turning on resources %d\n", ret);
+               return ret;
+       }
+       proto = geni_se_read_proto(&gi2c->se);
+       tx_depth = geni_se_get_tx_fifo_depth(&gi2c->se);
+       if (unlikely(proto != GENI_SE_I2C)) {
+               dev_err(&pdev->dev, "Invalid proto %d\n", proto);
+               geni_se_resources_off(&gi2c->se);
+               return -ENXIO;
+       }
+       gi2c->tx_wm = tx_depth - 1;
+       geni_se_init(&gi2c->se, gi2c->tx_wm, tx_depth);
+       geni_se_config_packing(&gi2c->se, BITS_PER_BYTE, PACKING_BYTES_PW,
+                                                       true, true, true);
+       geni_se_resources_off(&gi2c->se);
+       dev_dbg(&pdev->dev, "i2c fifo/se-dma mode. fifo depth:%d\n", tx_depth);
+
+       pm_runtime_set_suspended(gi2c->se.dev);
+       pm_runtime_set_autosuspend_delay(gi2c->se.dev, I2C_AUTO_SUSPEND_DELAY);
+       pm_runtime_use_autosuspend(gi2c->se.dev);
+       pm_runtime_enable(gi2c->se.dev);
+       i2c_add_adapter(&gi2c->adap);
+
+       dev_dbg(&pdev->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->se.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->se);
+       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->se);
+       if (ret)
+               return ret;
+
+       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->se.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,geni-i2c" },
+       {}
+};
+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 = "geni_i2c",
+               .pm = &geni_i2c_pm_ops,
+               .of_match_table = geni_i2c_dt_match,
+       },
+};
+
+module_platform_driver(geni_i2c_driver);
+
+MODULE_DESCRIPTION("I2C Controller Driver for GENI based QUP cores");
+MODULE_LICENSE("GPL v2");
-- 
Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

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