From 4d51b4cea21831422614366de4e929701846d801 Mon Sep 17 00:00:00 2001 From: Patrick Williams Date: Tue, 1 Oct 2019 10:59:59 -0500 Subject: i2c: pxa: migrate to new i2c_slave APIs The i2c subsystem was enhanced circa 2015 to support operating as an i2c-slave device. Prior to that, the i2c-pxa driver supported an i2c-slave but had its own APIs. There are no existing in-kernel drivers or platforms that utilize the i2c-pxa APIs. Migrate the i2c-pxa driver to the general i2c-slave APIs so that existing drivers, such as the i2c-slave-eeprom, can be used. This has been tested with a Marvell EspressoBin, using i2c-pxa and i2c-slave-eeprom, acting as a slave, and a RaspeberryPi 3, using the at24 driver, acting as a master. Signed-off-by: Patrick Williams Signed-off-by: Wolfram Sang --- drivers/i2c/busses/Kconfig | 1 + drivers/i2c/busses/i2c-pxa.c | 74 +++++++++++++++++++++++++++++++++++--------- 2 files changed, 61 insertions(+), 14 deletions(-) (limited to 'drivers/i2c/busses') diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 89cb8d7c4853..45ca099e7315 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -875,6 +875,7 @@ config I2C_PXA_PCI config I2C_PXA_SLAVE bool "Intel PXA2XX I2C Slave comms support" depends on I2C_PXA && !X86_32 + select I2C_SLAVE help Support I2C slave mode communications on the PXA I2C bus. This is necessary for systems where the PXA may be a target on the diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c index 2c3c3d6935c0..c811646e809f 100644 --- a/drivers/i2c/busses/i2c-pxa.c +++ b/drivers/i2c/busses/i2c-pxa.c @@ -180,7 +180,7 @@ struct pxa_i2c { struct i2c_adapter adap; struct clk *clk; #ifdef CONFIG_I2C_PXA_SLAVE - struct i2c_slave_client *slave; + struct i2c_client *slave; #endif unsigned int irqlogidx; @@ -544,22 +544,23 @@ static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr) if (isr & ISR_BED) { /* what should we do here? */ } else { - int ret = 0; + u8 byte = 0; if (i2c->slave != NULL) - ret = i2c->slave->read(i2c->slave->data); + i2c_slave_event(i2c->slave, I2C_SLAVE_READ_PROCESSED, + &byte); - writel(ret, _IDBR(i2c)); + writel(byte, _IDBR(i2c)); writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c)); /* allow next byte */ } } static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr) { - unsigned int byte = readl(_IDBR(i2c)); + u8 byte = readl(_IDBR(i2c)); if (i2c->slave != NULL) - i2c->slave->write(i2c->slave->data, byte); + i2c_slave_event(i2c->slave, I2C_SLAVE_WRITE_RECEIVED, &byte); writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c)); } @@ -572,9 +573,18 @@ static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr) dev_dbg(&i2c->adap.dev, "SAD, mode is slave-%cx\n", (isr & ISR_RWM) ? 'r' : 't'); - if (i2c->slave != NULL) - i2c->slave->event(i2c->slave->data, - (isr & ISR_RWM) ? I2C_SLAVE_EVENT_START_READ : I2C_SLAVE_EVENT_START_WRITE); + if (i2c->slave != NULL) { + if (isr & ISR_RWM) { + u8 byte = 0; + + i2c_slave_event(i2c->slave, I2C_SLAVE_READ_REQUESTED, + &byte); + writel(byte, _IDBR(i2c)); + } else { + i2c_slave_event(i2c->slave, I2C_SLAVE_WRITE_REQUESTED, + NULL); + } + } /* * slave could interrupt in the middle of us generating a @@ -607,7 +617,7 @@ static void i2c_pxa_slave_stop(struct pxa_i2c *i2c) dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop)\n"); if (i2c->slave != NULL) - i2c->slave->event(i2c->slave->data, I2C_SLAVE_EVENT_STOP); + i2c_slave_event(i2c->slave, I2C_SLAVE_STOP, NULL); if (i2c_debug > 2) dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop) acked\n"); @@ -619,6 +629,38 @@ static void i2c_pxa_slave_stop(struct pxa_i2c *i2c) if (i2c->msg) i2c_pxa_master_complete(i2c, I2C_RETRY); } + +static int i2c_pxa_slave_reg(struct i2c_client *slave) +{ + struct pxa_i2c *i2c = slave->adapter->algo_data; + + if (i2c->slave) + return -EBUSY; + + if (!i2c->reg_isar) + return -EAFNOSUPPORT; + + i2c->slave = slave; + i2c->slave_addr = slave->addr; + + writel(i2c->slave_addr, _ISAR(i2c)); + + return 0; +} + +static int i2c_pxa_slave_unreg(struct i2c_client *slave) +{ + struct pxa_i2c *i2c = slave->adapter->algo_data; + + WARN_ON(!i2c->slave); + + i2c->slave_addr = I2C_PXA_SLAVE_ADDR; + writel(i2c->slave_addr, _ISAR(i2c)); + + i2c->slave = NULL; + + return 0; +} #else static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr) { @@ -1141,11 +1183,19 @@ static u32 i2c_pxa_functionality(struct i2c_adapter *adap) static const struct i2c_algorithm i2c_pxa_algorithm = { .master_xfer = i2c_pxa_xfer, .functionality = i2c_pxa_functionality, +#ifdef CONFIG_I2C_PXA_SLAVE + .reg_slave = i2c_pxa_slave_reg, + .unreg_slave = i2c_pxa_slave_unreg, +#endif }; static const struct i2c_algorithm i2c_pxa_pio_algorithm = { .master_xfer = i2c_pxa_pio_xfer, .functionality = i2c_pxa_functionality, +#ifdef CONFIG_I2C_PXA_SLAVE + .reg_slave = i2c_pxa_slave_reg, + .unreg_slave = i2c_pxa_slave_unreg, +#endif }; static const struct of_device_id i2c_pxa_dt_ids[] = { @@ -1270,10 +1320,6 @@ static int i2c_pxa_probe(struct platform_device *dev) i2c->highmode_enter = false; if (plat) { -#ifdef CONFIG_I2C_PXA_SLAVE - i2c->slave_addr = plat->slave_addr; - i2c->slave = plat->slave; -#endif i2c->adap.class = plat->class; } -- cgit v1.2.3