> > > > The patch supports slave mode for imx I2C driver > > > > Signed-off-by: Biwen Li <biwen.li@xxxxxxx> > > Thank you for your work! > > Acked-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx> > > @Wolfram, Christian Eggers I2SR_IAL patches should go before this one. Hi Wolfram, Any progress? Regards, Biwen Li > > > --- > > Change in v10: > > - totally remove CONFIG_I2C_SLAVE > > - replace api with i2c_imx_clart_irq() > > - remove robust code > > - place pm_runtime_get in i2c_imx_slave_init() > > to i2c_imx_reg_slave() > > - apply the patch on top of this patch set: > > [PATCH v6 0/3] i2c: imx: Fix handling of arbitration loss > > https://lkml.org/lkml/2020/10/9/407 > > > > Change in v9: > > - remove #ifdef after select I2C_SLAVE by default > > > > Change in v8: > > - fix build issue > > > > Change in v7: > > - support auto switch mode between master and slave > > - enable interrupt when idle in slave mode > > - remove #ifdef > > > > Change in v6: > > - delete robust logs and comments > > - not read status register again in master isr. > > > > Change in v5: > > - fix a bug that cannot determine in what mode(master mode or > > slave mode) > > > > Change in v4: > > - add MACRO CONFIG_I2C_SLAVE to fix compilation issue > > > > Change in v3: > > - support layerscape and i.mx platform > > > > Change in v2: > > - remove MACRO CONFIG_I2C_SLAVE > > > > drivers/i2c/busses/Kconfig | 1 + > > drivers/i2c/busses/i2c-imx.c | 219 > > +++++++++++++++++++++++++++++++---- > > 2 files changed, 196 insertions(+), 24 deletions(-) > > > > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig > > index a97a9d058198..e2ad62481f25 100644 > > --- a/drivers/i2c/busses/Kconfig > > +++ b/drivers/i2c/busses/Kconfig > > @@ -675,6 +675,7 @@ config I2C_IMG > > config I2C_IMX > > tristate "IMX I2C interface" > > depends on ARCH_MXC || ARCH_LAYERSCAPE || COLDFIRE > > + select I2C_SLAVE > > help > > Say Y here if you want to use the IIC bus controller on > > the Freescale i.MX/MXC, Layerscape or ColdFire processors. > > diff --git a/drivers/i2c/busses/i2c-imx.c > > b/drivers/i2c/busses/i2c-imx.c index e6f8d6e45a15..a8e8af57e33f 100644 > > --- a/drivers/i2c/busses/i2c-imx.c > > +++ b/drivers/i2c/busses/i2c-imx.c > > @@ -17,6 +17,7 @@ > > * Copyright (C) 2008 Darius Augulis <darius.augulis at teltonika.lt> > > * > > * Copyright 2013 Freescale Semiconductor, Inc. > > + * Copyright 2020 NXP > > * > > */ > > > > @@ -73,6 +74,11 @@ > > #define IMX_I2C_I2SR 0x03 /* i2c status */ > > #define IMX_I2C_I2DR 0x04 /* i2c transfer data */ > > > > +/* > > + * All of the layerscape series SoCs support IBIC register. > > + */ > > +#define IMX_I2C_IBIC 0x05 /* i2c bus interrupt config */ > > + > > #define IMX_I2C_REGSHIFT 2 > > #define VF610_I2C_REGSHIFT 0 > > > > @@ -91,6 +97,7 @@ > > #define I2CR_MSTA 0x20 > > #define I2CR_IIEN 0x40 > > #define I2CR_IEN 0x80 > > +#define IBIC_BIIE 0x80 /* Bus idle interrupt enable */ > > > > /* register bits different operating codes definition: > > * 1) I2SR: Interrupt flags clear operation differ between SoCs: > > @@ -201,6 +208,7 @@ struct imx_i2c_struct { > > struct pinctrl_state *pinctrl_pins_gpio; > > > > struct imx_i2c_dma *dma; > > + struct i2c_client *slave; > > }; > > > > static const struct imx_i2c_hwdata imx1_i2c_hwdata = { @@ -265,6 > > +273,11 @@ static inline int is_imx1_i2c(struct imx_i2c_struct *i2c_imx) > > return i2c_imx->hwdata->devtype == IMX1_I2C; } > > > > +static inline int is_vf610_i2c(struct imx_i2c_struct *i2c_imx) { > > + return i2c_imx->hwdata->devtype == VF610_I2C; } > > + > > static inline void imx_i2c_write_reg(unsigned int val, > > struct imx_i2c_struct *i2c_imx, unsigned int reg) { @@ -277,6 > > +290,27 @@ static inline unsigned char imx_i2c_read_reg(struct > imx_i2c_struct *i2c_imx, > > return readb(i2c_imx->base + (reg << i2c_imx->hwdata->regshift)); } > > > > +static void i2c_imx_clear_irq(struct imx_i2c_struct *i2c_imx, > > +unsigned int bits) { > > + unsigned int temp; > > + > > + /* > > + * i2sr_clr_opcode is the value to clear all interrupts. Here we want to > > + * clear only <bits>, so we write ~i2sr_clr_opcode with just <bits> > > + * toggled. This is required because i.MX needs W0C and Vybrid uses W1C. > > + */ > > + temp = ~i2c_imx->hwdata->i2sr_clr_opcode ^ bits; > > + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR); } > > + > > +/* 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); > > + i2c_imx_clear_irq(i2c_imx, I2SR_IIF | I2SR_IAL); } > > + > > /* Functions for DMA support */ > > static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx, > > dma_addr_t phy_addr) > > @@ -412,19 +446,6 @@ static void i2c_imx_dma_free(struct imx_i2c_struct > *i2c_imx) > > dma->chan_using = NULL; > > } > > > > -static void i2c_imx_clear_irq(struct imx_i2c_struct *i2c_imx, > > unsigned int bits) -{ > > - unsigned int temp; > > - > > - /* > > - * i2sr_clr_opcode is the value to clear all interrupts. Here we want to > > - * clear only <bits>, so we write ~i2sr_clr_opcode with just <bits> > > - * toggled. This is required because i.MX needs W0C and Vybrid uses W1C. > > - */ > > - temp = ~i2c_imx->hwdata->i2sr_clr_opcode ^ bits; > > - imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR); > > -} > > - > > static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int > > for_busy, bool atomic) { > > unsigned long orig_jiffies = jiffies; @@ -638,18 +659,165 @@ static > > void i2c_imx_stop(struct imx_i2c_struct *i2c_imx, bool atomic) > > imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); } > > > > +/* > > + * Enable bus idle interrupts > > + * Note: IBIC register will be cleared after disabled i2c module. > > + * All of layerscape series SoCs support IBIC register. > > + */ > > +static void i2c_imx_enable_bus_idle(struct imx_i2c_struct *i2c_imx) { > > + if (is_vf610_i2c(i2c_imx)) { > > + unsigned int temp; > > + > > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_IBIC); > > + temp |= IBIC_BIIE; > > + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_IBIC); > > + } > > +} > > + > > +static irqreturn_t i2c_imx_slave_isr(struct imx_i2c_struct *i2c_imx, > > + unsigned int status, unsigned int ctl) { > > + u8 value; > > + > > + if (status & I2SR_IAL) { /* Arbitration lost */ > > + i2c_imx_clear_irq(i2c_imx, I2SR_IAL); > > + if (!(status & I2SR_IAAS)) > > + return IRQ_HANDLED; > > + } > > + > > + 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 */ > > + 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 void i2c_imx_slave_init(struct imx_i2c_struct *i2c_imx) { > > + int 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); > > + > > + i2c_imx_enable_bus_idle(i2c_imx); > > +} > > + > > +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; > > + > > + /* Resume */ > > + ret = pm_runtime_get_sync(i2c_imx->adapter.dev.parent); > > + if (ret < 0) { > > + dev_err(&i2c_imx->adapter.dev, "failed to resume i2c controller"); > > + return ret; > > + } > > + > > + i2c_imx_slave_init(i2c_imx); > > + > > + return 0; > > +} > > + > > +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; > > +} > > + > > +static irqreturn_t i2c_imx_master_isr(struct imx_i2c_struct *i2c_imx, > > +unsigned int status) { > > + /* save status register */ > > + i2c_imx->i2csr = status; > > + wake_up(&i2c_imx->queue); > > + > > + return IRQ_HANDLED; > > +} > > + > > static irqreturn_t i2c_imx_isr(int irq, void *dev_id) { > > struct imx_i2c_struct *i2c_imx = dev_id; > > - unsigned int temp; > > + unsigned int ctl, status; > > > > - temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); > > - if (temp & I2SR_IIF) { > > - /* save status register */ > > - i2c_imx->i2csr = temp; > > + 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_clear_irq(i2c_imx, I2SR_IIF); > > - wake_up(&i2c_imx->queue); > > - return IRQ_HANDLED; > > + if (i2c_imx->slave && !(ctl & I2CR_MSTA)) > > + return i2c_imx_slave_isr(i2c_imx, status, ctl); > > + return i2c_imx_master_isr(i2c_imx, status); > > } > > > > return IRQ_NONE; > > @@ -1027,6 +1195,10 @@ static int i2c_imx_xfer_common(struct > i2c_adapter *adapter, > > dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__, > > (result < 0) ? "error" : "success msg", > > (result < 0) ? result : num); > > + /* After data is transferred, switch to slave mode(as a receiver) */ > > + if (i2c_imx->slave) > > + i2c_imx_slave_init(i2c_imx); > > + > > return (result < 0) ? result : num; > > } > > > > @@ -1140,6 +1312,8 @@ static const struct i2c_algorithm i2c_imx_algo = { > > .master_xfer = i2c_imx_xfer, > > .master_xfer_atomic = i2c_imx_xfer_atomic, > > .functionality = i2c_imx_func, > > + .reg_slave = i2c_imx_reg_slave, > > + .unreg_slave = i2c_imx_unreg_slave, > > }; > > > > static int i2c_imx_probe(struct platform_device *pdev) @@ -1233,10 > > +1407,7 @@ static int i2c_imx_probe(struct platform_device *pdev) > > clk_notifier_register(i2c_imx->clk, &i2c_imx->clk_change_nb); > > i2c_imx_set_clk(i2c_imx, clk_get_rate(i2c_imx->clk)); > > > > - /* 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 function */ > > ret = i2c_imx_init_recovery_info(i2c_imx, pdev); > > -- > > 2.17.1 > > > > > > -- > Pengutronix e.K. | > | > Steuerwalder Str. 21 | http://www.pengutronix.de/ > | > 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 > | > Amtsgericht Hildesheim, HRA 2686 | Fax: > +49-5121-206917-5555 |
