+++ /dev/null
-From 865433df5d11aef7cfe5d51b362b6276bddb7a15 Mon Sep 17 00:00:00 2001
-From: Biwen Li <biwen.li@nxp.com>
-Date: Fri, 2 Aug 2019 17:45:56 +0800
-Subject: [PATCH] i2c: imx: support slave mode for imx I2C driver
-
-The patch supports slave mode for imx I2C driver
-
-Reviewed-by: Clark Wang <xiaoning.wang@nxp.com>
-Signed-off-by: Biwen Li <biwen.li@nxp.com>
----
- drivers/i2c/busses/i2c-imx.c | 219 +++++++++++++++++++++++++++++++++++++++----
- 1 file changed, 201 insertions(+), 18 deletions(-)
-
---- a/drivers/i2c/busses/i2c-imx.c
-+++ b/drivers/i2c/busses/i2c-imx.c
-@@ -265,6 +265,9 @@ struct imx_i2c_struct {
- int pmuxcr_set;
- int pmuxcr_endian;
- void __iomem *pmuxcr_addr;
-+#if IS_ENABLED(CONFIG_I2C_SLAVE)
-+ struct i2c_client *slave;
-+#endif
- };
-
- static const struct imx_i2c_hwdata imx1_i2c_hwdata = {
-@@ -357,6 +360,14 @@ static inline unsigned char imx_i2c_read
- return readb(i2c_imx->base + (reg << i2c_imx->hwdata->regshift));
- }
-
-+/* Set up i2c controller register and i2c status register to default value. */
-+static void i2c_imx_reset_regs(struct imx_i2c_struct *i2c_imx)
-+{
-+ imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN,
-+ i2c_imx, IMX_I2C_I2CR);
-+ imx_i2c_write_reg(i2c_imx->hwdata->i2sr_clr_opcode, i2c_imx, IMX_I2C_I2SR);
-+}
-+
- /* Functions for DMA support */
- static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
- dma_addr_t phy_addr)
-@@ -705,21 +716,33 @@ static void i2c_imx_stop(struct imx_i2c_
- imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
- }
-
--static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
-+/* Clear interrupt flag bit */
-+static void i2c_imx_clr_if_bit(unsigned int status, struct imx_i2c_struct *i2c_imx)
- {
-- struct imx_i2c_struct *i2c_imx = dev_id;
-- unsigned int temp;
-+ status &= ~I2SR_IIF;
-+ status |= (i2c_imx->hwdata->i2sr_clr_opcode & I2SR_IIF);
-+ imx_i2c_write_reg(status, i2c_imx, IMX_I2C_I2SR);
-+}
-
-- temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
-- if (temp & I2SR_IIF) {
-- /* save status register */
-- i2c_imx->i2csr = temp;
-- i2c_imx_clear_irq(i2c_imx, I2SR_IIF);
-- wake_up(&i2c_imx->queue);
-- return IRQ_HANDLED;
-- }
-+/* Clear arbitration lost bit */
-+static void i2c_imx_clr_al_bit(unsigned int status, struct imx_i2c_struct *i2c_imx)
-+{
-+ status &= ~I2SR_IAL;
-+ status |= (i2c_imx->hwdata->i2sr_clr_opcode & I2SR_IAL);
-+ imx_i2c_write_reg(status, i2c_imx, IMX_I2C_I2SR);
-+}
-+
-+static irqreturn_t i2c_imx_master_isr(struct imx_i2c_struct *i2c_imx)
-+{
-+ unsigned int status;
-+
-+ /* Save status register */
-+ status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
-+ i2c_imx->i2csr = status | I2SR_IIF;
-+
-+ wake_up(&i2c_imx->queue);
-
-- return IRQ_NONE;
-+ return IRQ_HANDLED;
- }
-
- static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx,
-@@ -1094,6 +1117,13 @@ static int i2c_imx_xfer(struct i2c_adapt
-
- dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
-
-+#if IS_ENABLED(CONFIG_I2C_SLAVE)
-+ if (i2c_imx->slave) {
-+ dev_err(&i2c_imx->adapter.dev, "Please not do operations of master mode in slave mode");
-+ return -EBUSY;
-+ }
-+#endif
-+
- if (!pm_runtime_enabled(i2c_imx->adapter.dev.parent)) {
- pm_runtime_enable(i2c_imx->adapter.dev.parent);
- enable_runtime_pm = true;
-@@ -1307,11 +1337,169 @@ static u32 i2c_imx_func(struct i2c_adapt
- | I2C_FUNC_SMBUS_READ_BLOCK_DATA;
- }
-
-+#if IS_ENABLED(CONFIG_I2C_SLAVE)
-+static int i2c_imx_slave_init(struct imx_i2c_struct *i2c_imx)
-+{
-+ int temp;
-+
-+ /* Resume */
-+ temp = pm_runtime_get_sync(i2c_imx->adapter.dev.parent);
-+ if (temp < 0) {
-+ dev_err(&i2c_imx->adapter.dev, "failed to resume i2c controller");
-+ return temp;
-+ }
-+
-+ /* Set slave addr. */
-+ imx_i2c_write_reg((i2c_imx->slave->addr << 1), i2c_imx, IMX_I2C_IADR);
-+
-+ i2c_imx_reset_regs(i2c_imx);
-+
-+ /* Enable module */
-+ temp = i2c_imx->hwdata->i2cr_ien_opcode;
-+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
-+
-+ /* Enable interrupt from i2c module */
-+ temp |= I2CR_IIEN;
-+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
-+
-+ /* Wait controller to be stable */
-+ usleep_range(50, 150);
-+ return 0;
-+}
-+
-+static irqreturn_t i2c_imx_slave_isr(struct imx_i2c_struct *i2c_imx)
-+{
-+ unsigned int status, ctl;
-+ u8 value;
-+
-+ if (!i2c_imx->slave) {
-+ dev_err(&i2c_imx->adapter.dev, "cannot deal with slave irq,i2c_imx->slave is null");
-+ return IRQ_NONE;
-+ }
-+
-+ status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
-+ ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
-+ if (status & I2SR_IAL) { /* Arbitration lost */
-+ i2c_imx_clr_al_bit(status, i2c_imx);
-+ } else if (status & I2SR_IAAS) { /* Addressed as a slave */
-+ if (status & I2SR_SRW) { /* Master wants to read from us*/
-+ dev_dbg(&i2c_imx->adapter.dev, "read requested");
-+ i2c_slave_event(i2c_imx->slave, I2C_SLAVE_READ_REQUESTED, &value);
-+
-+ /* Slave transmit */
-+ ctl |= I2CR_MTX;
-+ imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR);
-+
-+ /* Send data */
-+ imx_i2c_write_reg(value, i2c_imx, IMX_I2C_I2DR);
-+ } else { /* Master wants to write to us */
-+ dev_dbg(&i2c_imx->adapter.dev, "write requested");
-+ i2c_slave_event(i2c_imx->slave, I2C_SLAVE_WRITE_REQUESTED, &value);
-+
-+ /* Slave receive */
-+ ctl &= ~I2CR_MTX;
-+ imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR);
-+ /* Dummy read */
-+ imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
-+ }
-+ } else if (!(ctl & I2CR_MTX)) { /* Receive mode */
-+ if (status & I2SR_IBB) { /* No STOP signal detected */
-+ ctl &= ~I2CR_MTX;
-+ imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR);
-+
-+ value = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
-+ i2c_slave_event(i2c_imx->slave, I2C_SLAVE_WRITE_RECEIVED, &value);
-+ } else { /* STOP signal is detected */
-+ dev_dbg(&i2c_imx->adapter.dev,
-+ "STOP signal detected");
-+ i2c_slave_event(i2c_imx->slave, I2C_SLAVE_STOP, &value);
-+ }
-+ } else if (!(status & I2SR_RXAK)) { /* Transmit mode received ACK */
-+ ctl |= I2CR_MTX;
-+ imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR);
-+
-+ i2c_slave_event(i2c_imx->slave, I2C_SLAVE_READ_PROCESSED, &value);
-+
-+ imx_i2c_write_reg(value, i2c_imx, IMX_I2C_I2DR);
-+ } else { /* Transmit mode received NAK */
-+ ctl &= ~I2CR_MTX;
-+ imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR);
-+ imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
-+ }
-+ return IRQ_HANDLED;
-+}
-+
-+static int i2c_imx_reg_slave(struct i2c_client *client)
-+{
-+ struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(client->adapter);
-+ int ret;
-+ if (i2c_imx->slave)
-+ return -EBUSY;
-+
-+ i2c_imx->slave = client;
-+
-+ ret = i2c_imx_slave_init(i2c_imx);
-+ if (ret < 0)
-+ dev_err(&i2c_imx->adapter.dev, "failed to switch to slave mode");
-+
-+ return ret;
-+}
-+
-+static int i2c_imx_unreg_slave(struct i2c_client *client)
-+{
-+ struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(client->adapter);
-+ int ret;
-+
-+ if (!i2c_imx->slave)
-+ return -EINVAL;
-+
-+ /* Reset slave address. */
-+ imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IADR);
-+
-+ i2c_imx_reset_regs(i2c_imx);
-+
-+ i2c_imx->slave = NULL;
-+
-+ /* Suspend */
-+ ret = pm_runtime_put_sync(i2c_imx->adapter.dev.parent);
-+ if (ret < 0)
-+ dev_err(&i2c_imx->adapter.dev, "failed to suspend i2c controller");
-+
-+ return ret;
-+}
-+#endif
-+
- static const struct i2c_algorithm i2c_imx_algo = {
- .master_xfer = i2c_imx_xfer,
- .functionality = i2c_imx_func,
-+#if IS_ENABLED(CONFIG_I2C_SLAVE)
-+ .reg_slave = i2c_imx_reg_slave,
-+ .unreg_slave = i2c_imx_unreg_slave,
-+#endif
- };
-
-+static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
-+{
-+ struct imx_i2c_struct *i2c_imx = dev_id;
-+ unsigned int status, ctl;
-+ irqreturn_t irq_status = IRQ_NONE;
-+
-+ status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
-+ ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
-+
-+ if (status & I2SR_IIF) {
-+ i2c_imx_clr_if_bit(status, i2c_imx);
-+ if (ctl & I2CR_MSTA)
-+ irq_status = i2c_imx_master_isr(i2c_imx);
-+#if IS_ENABLED(CONFIG_I2C_SLAVE)
-+ else
-+ irq_status = i2c_imx_slave_isr(i2c_imx);
-+#endif
-+ }
-+
-+ return irq_status;
-+}
-+
- static int i2c_imx_probe(struct platform_device *pdev)
- {
- struct imx_i2c_struct *i2c_imx;
-@@ -1420,10 +1608,7 @@ static int i2c_imx_probe(struct platform
- if (is_imx7d_i2c(i2c_imx) && i2c_imx->bitrate > IMX_I2C_MAX_E_BIT_RATE)
- i2c_imx->bitrate = IMX_I2C_MAX_E_BIT_RATE;
-
-- /* Set up chip registers to defaults */
-- imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN,
-- i2c_imx, IMX_I2C_I2CR);
-- imx_i2c_write_reg(i2c_imx->hwdata->i2sr_clr_opcode, i2c_imx, IMX_I2C_I2SR);
-+ i2c_imx_reset_regs(i2c_imx);
-
- /* Init optional bus recovery */
- if (of_match_node(pinmux_of_match, pdev->dev.of_node))
projects / openwrt / staging / wigyori.git / blobdiff