Hi Max, today I finally had the time to test your i2c driver. Before testing I adapted it to our newly agreed grf handling, the result can be found at [0]. Works like a charm :-) . As you can see, support for the upcoming rk3288 is also included - which only supports the new-style i2c IP and thus does not contain this switch. In the referenced commit I've also moved some init stuff around, which I'll explain a bit more inline below. [0] https://github.com/mmind/linux-rockchip/commit/9305a8a55ed9d97a07d0195d79d178ce6f97e77e Am Mittwoch, 30. April 2014, 00:34:36 schrieb Heiko Stübner: > Am Dienstag, 29. April 2014, 01:34:15 schrieb Max Schwarz: > > Driver for the native I2C adapter found in Rockchip RK3xxx SoCs. > > > > Configuration is only possible through devicetree. The driver is > > interrupt driven and supports the I2C_M_IGNORE_NAK mangling bit. > > > > Tested on the Radxa Rock board, which is based on RK3188. > > > > Signed-off-by: Max Schwarz <max.schwarz@xxxxxxxxx> > > --- > > > > changes since v1: > > - dt property names "rockchip,*" suggested by Heiko Stübner > > - fixed overly specific RK3188 comment (Heiko Stübner) > > > > The dts files needed for testing on Radxa Rock are in my tree on > > > > https://github.com/xqms/linux.git topic/i2c-rk3x-clean-v2 > > > > Documentation/devicetree/bindings/i2c/i2c-rk3x.txt | 34 + > > drivers/i2c/busses/Kconfig | 10 + > > drivers/i2c/busses/Makefile | 1 + > > drivers/i2c/busses/i2c-rk3x.c | 731 > > > > +++++++++++++++++++++ 4 files changed, 776 insertions(+) > > > > create mode 100644 Documentation/devicetree/bindings/i2c/i2c-rk3x.txt > > create mode 100644 drivers/i2c/busses/i2c-rk3x.c > > > > diff --git a/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt > > b/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt new file mode 100644 > > index 0000000..19bd386 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt > > @@ -0,0 +1,34 @@ > > +* Rockchip RK3xxx I2C controller > > + > > +This driver interfaces with the native I2C controller present in Rockchip > > +RK3xxx SoCs. > > + > > +Required properties : > > + > > + - reg : Offset and length of the register set for the device > > + - compatible : should be "rockchip,rk3x-i2c" > > sorry to see it only in the second iteration, but I think the common way for > compatibles is to name it after the first device to introduce it (like > "rockchip,rk3066-i2c") and newer devices are then simply compatible with > it. > > + - interrupts : interrupt number > > + - clocks : parent clock > > + - rockchip,grf : the phandle of the syscon node for the general register > > + file (GRF) > > + - rockchip,bus-index : index of the bus in the GRF > > here I only want to make sure, we'll be handling the GRF in general > correctly - see other thread about rockchip-pinctrl from some minutes ago. > > If the whole-grf-as-syscon case wins, the best way to declare the offset > would probably be to use the data field of rk3x_i2c_match below and > introduce a second "rockchip,rk3188-i2c" compatible for it, for example > like the rockchip- pinctrl driver does in its rockchip_pinctrl_dt_match > array. > > > Heiko > > > + > > +Optional properties : > > + > > + - clock-frequency : SCL frequency to use (in Hz). If omitted, 100kHz is > > used. + > > +Example: > > + > > +i2c0: i2c@2002d000 { > > + compatible = "rockchip,rk3x-i2c"; > > + reg = <0x2002d000 0x1000>; > > + interrupts = <GIC_SPI 40 IRQ_TYPE_LEVEL_HIGH>; > > + #address-cells = <1>; > > + #size-cells = <0>; > > + > > + rockchip,grf = <&grf>; > > + rockchip,bus-index = <0>; > > + > > + clock-names = "i2c"; > > + clocks = <&cru PCLK_I2C0>; > > +}; > > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig > > index c94db1c..f973632 100644 > > --- a/drivers/i2c/busses/Kconfig > > +++ b/drivers/i2c/busses/Kconfig > > @@ -663,6 +663,16 @@ config I2C_PXA_SLAVE > > > > is necessary for systems where the PXA may be a target on the > > I2C bus. > > > > +config I2C_RK3X > > + tristate "Rockchip RK3xxx I2C adapter" > > + depends on OF > > + help > > + Say Y here to include support for the I2C adapter in Rockchip RK3xxx > > + SoCs. > > + > > + This driver can also be built as a module. If so, the module will > > + be called i2c-rk3x. > > + > > > > 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 18d18ff..39b6851 100644 > > --- a/drivers/i2c/busses/Makefile > > +++ b/drivers/i2c/busses/Makefile > > @@ -65,6 +65,7 @@ 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-$(CONFIG_I2C_RK3X) += i2c-rk3x.o > > > > obj-$(CONFIG_I2C_QUP) += i2c-qup.o > > obj-$(CONFIG_I2C_RIIC) += i2c-riic.o > > obj-$(CONFIG_I2C_S3C2410) += i2c-s3c2410.o > > > > diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c > > new file mode 100644 > > index 0000000..73f1eb7 > > --- /dev/null > > +++ b/drivers/i2c/busses/i2c-rk3x.c > > @@ -0,0 +1,731 @@ > > +/* > > + * Driver for I2C adapter in Rockchip RK3xxx SoC > > + * > > + * Max Schwarz <max.schwarz@xxxxxxxxx> > > + * based on the patches by Rockchip Inc. > > + * > > + * This program is free software; you can redistribute it and/or modify > > + * it under the terms of the GNU General Public License version 2 as > > + * published by the Free Software Foundation. > > + */ > > + > > +#include <linux/kernel.h> > > +#include <linux/module.h> > > + > > +#include <linux/i2c.h> > > +#include <linux/time.h> > > +#include <linux/interrupt.h> > > +#include <linux/delay.h> > > +#include <linux/errno.h> > > +#include <linux/err.h> > > +#include <linux/platform_device.h> > > +#include <linux/io.h> > > +#include <linux/of_address.h> > > +#include <linux/of_irq.h> > > +#include <linux/spinlock.h> > > +#include <linux/clk.h> > > +#include <linux/wait.h> > > +#include <linux/mfd/syscon.h> > > +#include <linux/regmap.h> > > + > > + > > +/* Register Map */ > > +#define REG_CON 0x00 /* control register */ > > +#define REG_CLKDIV 0x04 /* clock divisor register */ > > +#define REG_MRXADDR 0x08 /* slave address for REGISTER_TX */ > > +#define REG_MRXRADDR 0x0c /* slave register address for REGISTER_TX */ > > +#define REG_MTXCNT 0x10 /* number of bytes to be transmitted */ > > +#define REG_MRXCNT 0x14 /* number of bytes to be received */ > > +#define REG_IEN 0x18 /* interrupt enable */ > > +#define REG_IPD 0x1c /* interrupt pending */ > > +#define REG_FCNT 0x20 /* finished count */ > > + > > +/* Data buffer offsets */ > > +#define TXBUFFER_BASE 0x100 > > +#define RXBUFFER_BASE 0x200 > > + > > +/* REG_CON bits */ > > +#define REG_CON_EN (1 << 0) > > +enum { > > + REG_CON_MOD_TX = 0, /* transmit data */ > > + REG_CON_MOD_REGISTER_TX, /* select register and restart */ > > + REG_CON_MOD_RX, /* receive data */ > > + REG_CON_MOD_REGISTER_RX, /* broken: transmits read addr AND writes > > + * register addr */ > > +}; > > +#define REG_CON_MOD(mod) ((mod) << 1) > > +#define REG_CON_MOD_MASK (3 << 1) > > +#define REG_CON_START (1 << 3) > > +#define REG_CON_STOP (1 << 4) > > +#define REG_CON_LASTACK (1 << 5) /* 1: do not send ACK after last > > receive */ +#define REG_CON_ACTACK (1 << 6) /* 1: stop if NACK is > > received */ + +/* REG_MRXADDR bits */ > > +#define REG_MRXADDR_LOW (1 << 24) /* bits [7:0] of MRX[R]ADDR are valid > > */ +#define REG_MRXADDR_MID (1 << 25) /* bits [15:8] of MRX[R]ADDR are > > valid */ +#define REG_MRXADDR_HIGH (1 << 26) /* bits [23:16] of > > MRX[R]ADDR > > are valid */ + > > +/* REG_IEN/REG_IPD bits */ > > +#define REG_INT_BTF (1 << 0) /* a byte was transmitted */ > > +#define REG_INT_BRF (1 << 1) /* a byte was received */ > > +#define REG_INT_MBTF (1 << 2) /* master data transmit finished */ > > +#define REG_INT_MBRF (1 << 3) /* master data receive finished */ > > +#define REG_INT_START (1 << 4) /* START condition generated */ > > +#define REG_INT_STOP (1 << 5) /* STOP condition generated */ > > +#define REG_INT_NAKRCV (1 << 6) /* NACK received */ > > +#define REG_INT_ALL 0x7f > > + > > +/* Registers in the GRF (General Register File) */ > > +#define GRF_SOC_CON1 4 > > + > > +/* Constants */ > > +#define WAIT_TIMEOUT 200 /* ms */ > > + > > +enum rk3x_i2c_state { > > + STATE_IDLE, > > + STATE_START, > > + STATE_READ, > > + STATE_WRITE, > > + STATE_STOP > > +}; > > + > > +struct rk3x_i2c { > > + struct i2c_adapter adap; > > + struct device *dev; > > + > > + /* Hardware resources */ > > + void __iomem *regs; > > + struct regmap *grf; > > + unsigned int bus_index; > > + struct clk *clk; > > + int irq; > > + > > + /* Settings */ > > + unsigned int scl_frequency; > > + > > + /* Synchronization & notification */ > > + spinlock_t lock; > > + wait_queue_head_t wait; > > + bool busy; > > + > > + /* Current message */ > > + struct i2c_msg *msg; > > + u8 addr; > > + unsigned int mode; > > + > > + /* I2C state machine */ > > + enum rk3x_i2c_state state; > > + unsigned int processed; /* sent/received bytes */ > > + int error; > > +}; > > + > > +static inline void i2c_writel(struct rk3x_i2c *i2c, u32 value, > > + unsigned int offset) > > +{ > > + writel(value, i2c->regs + offset); > > +} > > + > > +static inline u32 i2c_readl(struct rk3x_i2c *i2c, unsigned int offset) > > +{ > > + return readl(i2c->regs + offset); > > +} > > + > > +static inline int rk3x_i2c_set_grf_enable(struct rk3x_i2c *i2c, bool on) > > +{ > > + u32 con = BIT(27 + i2c->bus_index); /* write mask */ > > + > > + if (on) > > + con |= BIT(11 + i2c->bus_index); > > + > > + return regmap_write(i2c->grf, GRF_SOC_CON1, con); > > +} > > + > > +/* Reset all interrupt pending bits */ > > +static inline void rk3x_i2c_clean_ipd(struct rk3x_i2c *i2c) > > +{ > > + i2c_writel(i2c, REG_INT_ALL, REG_IPD); > > +} > > + > > +/** > > + * Generate a START condition, which triggers a REG_INT_START interrupt. > > + */ > > +static void rk3x_i2c_start(struct rk3x_i2c *i2c) > > +{ > > + u32 val; > > + > > + rk3x_i2c_clean_ipd(i2c); > > + i2c_writel(i2c, REG_INT_START, REG_IEN); > > + > > + /* enable adapter with correct mode, send START condition */ > > + val = REG_CON_EN | REG_CON_MOD(i2c->mode) | REG_CON_START; > > + > > + /* if we want to react to NACK, set ACTACK bit */ > > + if (!(i2c->msg->flags & I2C_M_IGNORE_NAK)) > > + val |= REG_CON_ACTACK; > > + > > + i2c_writel(i2c, val, REG_CON); > > +} > > + > > +/** > > + * Generate a STOP condition, which triggers a REG_INT_STOP interrupt. > > + * > > + * @error: Error code to return in rk3x_i2c_xfer > > + */ > > +static void rk3x_i2c_stop(struct rk3x_i2c *i2c, int error) > > +{ > > + unsigned int ctrl; > > + > > + i2c->processed = 0; > > + i2c->msg = 0; > > + i2c->error = error; > > + > > + /* Enable stop interrupt */ > > + i2c_writel(i2c, REG_INT_STOP, REG_IEN); > > + > > + i2c->state = STATE_STOP; > > + > > + ctrl = i2c_readl(i2c, REG_CON); > > + ctrl |= REG_CON_STOP; > > + i2c_writel(i2c, ctrl, REG_CON); > > +} > > + > > +/** > > + * Setup a read according to i2c->msg > > + */ > > +static void rk3x_i2c_prepare_read(struct rk3x_i2c *i2c) > > +{ > > + unsigned int len = i2c->msg->len - i2c->processed; > > + u32 con; > > + > > + con = i2c_readl(i2c, REG_CON); > > + > > + /* the hw can read up to 32 bytes at a time. If we need more than one > > + * chunk, send an ACK after the last byte of the current chunk. */ > > + if (unlikely(len > 32)) { > > + len = 32; > > + con &= ~REG_CON_LASTACK; > > + } else > > + con |= REG_CON_LASTACK; > > + > > + /* make sure we are in plain RX mode if we read a second chunk */ > > + if (i2c->processed != 0) { > > + con &= ~REG_CON_MOD_MASK; > > + con |= REG_CON_MOD(REG_CON_MOD_RX); > > + } > > + > > + i2c_writel(i2c, con, REG_CON); > > + i2c_writel(i2c, len, REG_MRXCNT); > > +} > > + > > +/** > > + * Fill the transmit buffer with data from i2c->msg > > + */ > > +static void rk3x_i2c_fill_transmit_buf(struct rk3x_i2c *i2c) > > +{ > > + unsigned int i, j; > > + u32 cnt = 0; > > + u32 val; > > + u8 byte; > > + > > + for (i = 0; i < 8; ++i) { > > + val = 0; > > + for (j = 0; j < 4; ++j) { > > + if (i2c->processed == i2c->msg->len) > > + break; > > + > > + if (i2c->processed == 0 && cnt == 0) > > + byte = (i2c->addr & 0x7f) << 1; > > + else > > + byte = i2c->msg->buf[i2c->processed++]; > > + > > + val |= byte << (j*8); > > + cnt++; > > + } > > + > > + i2c_writel(i2c, val, TXBUFFER_BASE + 4*i); > > + > > + if (i2c->processed == i2c->msg->len) > > + break; > > + } > > + > > + i2c_writel(i2c, cnt, REG_MTXCNT); > > +} > > + > > + > > +/* IRQ handlers for individual states */ > > + > > +static void rk3x_i2c_handle_start(struct rk3x_i2c *i2c, unsigned int ipd) > > +{ > > + if (!(ipd & REG_INT_START)) { > > + rk3x_i2c_stop(i2c, -ENXIO); > > + dev_warn(i2c->dev, "unexpected irq in START: 0x%x\n", ipd); > > + rk3x_i2c_clean_ipd(i2c); > > + return; > > + } > > + > > + /* ack interrupt */ > > + i2c_writel(i2c, REG_INT_START, REG_IPD); > > + > > + /* disable start bit */ > > + i2c_writel(i2c, i2c_readl(i2c, REG_CON) & ~REG_CON_START, REG_CON); > > + > > + /* enable appropriate interrupts and transition */ > > + if (i2c->mode == REG_CON_MOD_TX) { > > + i2c_writel(i2c, REG_INT_MBTF | REG_INT_NAKRCV, REG_IEN); > > + i2c->state = STATE_WRITE; > > + rk3x_i2c_fill_transmit_buf(i2c); > > + } else { > > + /* in any other case, we are going to be reading. */ > > + i2c_writel(i2c, REG_INT_MBRF | REG_INT_NAKRCV, REG_IEN); > > + i2c->state = STATE_READ; > > + rk3x_i2c_prepare_read(i2c); > > + } > > +} > > + > > +static void rk3x_i2c_handle_write(struct rk3x_i2c *i2c, unsigned int ipd) > > +{ > > + if (!(ipd & REG_INT_MBTF)) { > > + rk3x_i2c_stop(i2c, -ENXIO); > > + dev_err(i2c->dev, "unexpected irq in WRITE: 0x%x\n", ipd); > > + rk3x_i2c_clean_ipd(i2c); > > + return; > > + } > > + > > + /* ack interrupt */ > > + i2c_writel(i2c, REG_INT_MBTF, REG_IPD); > > + > > + /* are we finished? */ > > + if (i2c->processed == i2c->msg->len) > > + rk3x_i2c_stop(i2c, i2c->error); > > + else > > + rk3x_i2c_fill_transmit_buf(i2c); > > +} > > + > > +static void rk3x_i2c_handle_read(struct rk3x_i2c *i2c, unsigned int ipd) > > +{ > > + unsigned int i; > > + unsigned int len = i2c->msg->len - i2c->processed; > > + unsigned int val; > > + u8 byte; > > + > > + /* we only care for MBRF here. */ > > + if (!(ipd & REG_INT_MBRF)) > > + return; > > + > > + /* ack interrupt */ > > + i2c_writel(i2c, REG_INT_MBRF, REG_IPD); > > + > > + /* read the data from receive buffer */ > > + for (i = 0; i < len; ++i) { > > + if (i%4 == 0) > > + val = i2c_readl(i2c, RXBUFFER_BASE + (i/4)*4); > > + > > + byte = (val >> ((i%4) * 8)) & 0xff; > > + i2c->msg->buf[i2c->processed++] = byte; > > + } > > + > > + /* are we finished? */ > > + if (i2c->processed == i2c->msg->len) > > + rk3x_i2c_stop(i2c, i2c->error); > > + else > > + rk3x_i2c_prepare_read(i2c); > > +} > > + > > +static void rk3x_i2c_handle_stop(struct rk3x_i2c *i2c, unsigned int ipd) > > +{ > > + unsigned int con; > > + > > + if (!(ipd & REG_INT_STOP)) { > > + rk3x_i2c_stop(i2c, -ENXIO); > > + dev_err(i2c->dev, "unexpected irq in STOP: 0x%x\n", ipd); > > + rk3x_i2c_clean_ipd(i2c); > > + return; > > + } > > + > > + /* ack interrupt */ > > + i2c_writel(i2c, REG_INT_STOP, REG_IPD); > > + > > + /* disable STOP bit */ > > + con = i2c_readl(i2c, REG_CON); > > + con &= ~REG_CON_STOP; > > + i2c_writel(i2c, con, REG_CON); > > + > > + i2c->busy = 0; > > + i2c->state = STATE_IDLE; > > + > > + /* signal rk3x_i2c_xfer that we are finished */ > > + wake_up(&i2c->wait); > > +} > > + > > +static irqreturn_t rk3x_i2c_irq(int irqno, void *dev_id) > > +{ > > + struct rk3x_i2c *i2c = dev_id; > > + unsigned int ipd; > > + > > + spin_lock(&i2c->lock); > > + > > + ipd = i2c_readl(i2c, REG_IPD); > > + if (i2c->state == STATE_IDLE) { > > + dev_warn(i2c->dev, "irq in STATE_IDLE, ipd = 0x%x\n", ipd); > > + rk3x_i2c_clean_ipd(i2c); > > + goto out; > > + } > > + > > + dev_dbg(i2c->dev, "IRQ: state %d, ipd: %x\n", i2c->state, ipd); > > + > > + /* Clean interrupt bits we don't care about */ > > + ipd &= ~(REG_INT_BRF | REG_INT_BTF); > > + > > + if (ipd & REG_INT_NAKRCV) { > > + /* We got a NACK in the last operation. Depending on whether > > + * IGNORE_NAK is set, we have to stop the operation and report > > + * an error. */ > > + i2c_writel(i2c, REG_INT_NAKRCV, REG_IPD); > > + > > + ipd &= ~REG_INT_NAKRCV; > > + > > + if (!(i2c->msg->flags & I2C_M_IGNORE_NAK)) > > + rk3x_i2c_stop(i2c, -EAGAIN); > > + } > > + > > + /* is there anything left to handle? */ > > + if (unlikely(ipd == 0)) > > + goto out; > > + > > + switch (i2c->state) { > > + case STATE_START: > > + rk3x_i2c_handle_start(i2c, ipd); > > + break; > > + case STATE_WRITE: > > + rk3x_i2c_handle_write(i2c, ipd); > > + break; > > + case STATE_READ: > > + rk3x_i2c_handle_read(i2c, ipd); > > + break; > > + case STATE_STOP: > > + rk3x_i2c_handle_stop(i2c, ipd); > > + break; > > + case STATE_IDLE: > > + break; > > + } > > + > > +out: > > + spin_unlock(&i2c->lock); > > + return IRQ_HANDLED; > > +} > > + > > +static void rk3x_i2c_set_scl_rate(struct rk3x_i2c *i2c, unsigned long > > scl_rate) +{ > > + unsigned long i2c_rate = clk_get_rate(i2c->clk); > > + unsigned int div; > > + > > + /* SCL rate = (clk rate) / (8 * DIV) */ > > + div = DIV_ROUND_UP(i2c_rate, scl_rate * 8); > > + > > + /* The lower and upper half of the CLKDIV reg describe the length of > > + * SCL low & high periods. */ > > + div = DIV_ROUND_UP(div, 2); > > + > > + i2c_writel(i2c, (div << 16) | (div & 0xffff), REG_CLKDIV); > > +} > > + > > +/** > > + * Setup I2C registers for an I2C operation specified by msgs, num. > > + * > > + * Must be called with i2c->lock held. > > + * > > + * @msgs: I2C msgs to process > > + * @num: Number of msgs > > + * > > + * returns: Number of I2C msgs processed or negative in case of error > > + */ > > +static int rk3x_i2c_setup(struct rk3x_i2c *i2c, struct i2c_msg *msgs, int > > num) +{ > > + u32 addr = (msgs[0].addr & 0x7f) << 1; > > + int ret = 0; > > + > > + /* > > + * The I2C adapter can issue a small (len < 4) write packet before > > + * reading. This speeds up SMBus-style register reads. > > + * The MRXADDR/MRXRADDR hold the slave address and the slave register > > + * address in this case. > > + */ > > + > > + if (num >= 2 && msgs[0].len < 4 > > + && !(msgs[0].flags & I2C_M_RD) > > + && (msgs[1].flags & I2C_M_RD)) { > > + u32 reg_addr = 0; > > + > > + dev_dbg(i2c->dev, "Combined write/read from addr 0x%x\n", > > + addr >> 1); > > + > > + if (msgs[0].len == 0) > > + return -EINVAL; > > + > > + /* Fill MRXRADDR with the register address(es) */ > > + reg_addr = msgs[0].buf[0]; > > + reg_addr |= REG_MRXADDR_LOW; > > + > > + if (msgs[0].len >= 2) { > > + reg_addr |= msgs[0].buf[1] << 8; > > + reg_addr |= REG_MRXADDR_MID; > > + > > + if (msgs[0].len >= 3) { > > + reg_addr |= msgs[0].buf[2] << 16; > > + reg_addr |= REG_MRXADDR_HIGH; > > + } > > + } > > + > > + /* msgs[0] is handled by hw. */ > > + i2c->msg = &msgs[1]; > > + > > + i2c->mode = REG_CON_MOD_REGISTER_TX; > > + > > + i2c_writel(i2c, addr | REG_MRXADDR_LOW, REG_MRXADDR); > > + i2c_writel(i2c, reg_addr, REG_MRXRADDR); > > + > > + ret = 2; > > + } else { > > + /* We'll have to do it the boring way and process the msgs > > + * one-by-one. */ > > + > > + if (msgs[0].flags & I2C_M_RD) { > > + addr |= 1; /* set read bit */ > > + > > + /* We have to transmit the slave addr first. Use > > + * MOD_REGISTER_TX for that purpose. */ > > + i2c->mode = REG_CON_MOD_REGISTER_TX; > > + i2c_writel(i2c, addr | REG_MRXADDR_LOW, REG_MRXADDR); > > + i2c_writel(i2c, 0, REG_MRXRADDR); > > + } else { > > + i2c->mode = REG_CON_MOD_TX; > > + } > > + > > + i2c->msg = &msgs[0]; > > + > > + ret = 1; > > + } > > + > > + i2c->addr = msgs[0].addr; > > + i2c->busy = true; > > + i2c->state = STATE_START; > > + i2c->processed = 0; > > + i2c->error = 0; > > + > > + rk3x_i2c_clean_ipd(i2c); > > + > > + return ret; > > +} > > + > > +static int rk3x_i2c_xfer(struct i2c_adapter *adap, > > + struct i2c_msg *msgs, int num) > > +{ > > + struct rk3x_i2c *i2c = (struct rk3x_i2c *)adap->algo_data; > > + unsigned long timeout, flags; > > + int ret = 0; > > + int i; > > + > > + spin_lock_irqsave(&i2c->lock, flags); > > + > > + clk_enable(i2c->clk); > > + > > + /* The clock rate might have changed, so setup the divider again */ > > + rk3x_i2c_set_scl_rate(i2c, i2c->scl_frequency); > > + > > + /* Process msgs. We can handle more than one message at once (see > > + * rk3x_i2c_setup()). */ > > + for (i = 0; i < num; i += ret) { > > + ret = rk3x_i2c_setup(i2c, msgs + i, num); > > + > > + if (ret < 0) { > > + dev_err(i2c->dev, "rk3x_i2c_setup() failed\n"); > > + break; > > + } > > + > > + spin_unlock_irqrestore(&i2c->lock, flags); > > + > > + rk3x_i2c_start(i2c); > > + > > + timeout = wait_event_timeout(i2c->wait, !i2c->busy, > > + msecs_to_jiffies(WAIT_TIMEOUT)); > > + > > + spin_lock_irqsave(&i2c->lock, flags); > > + > > + if (timeout == 0) { > > + dev_err(i2c->dev, "timeout, ipd: 0x%08X", > > + i2c_readl(i2c, REG_IPD)); > > + > > + /* Force a STOP condition without interrupt */ > > + i2c_writel(i2c, 0, REG_IEN); > > + i2c_writel(i2c, REG_CON_EN | REG_CON_STOP, REG_CON); > > + > > + i2c->state = STATE_IDLE; > > + > > + ret = -ETIMEDOUT; > > + break; > > + } > > + > > + if (i2c->error) { > > + ret = i2c->error; > > + break; > > + } > > + } > > + > > + clk_disable(i2c->clk); > > + spin_unlock_irqrestore(&i2c->lock, flags); > > + > > + return ret; > > +} > > + > > +static u32 rk3x_i2c_func(struct i2c_adapter *adap) > > +{ > > + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING; > > +} > > + > > +static const struct i2c_algorithm rk3x_i2c_algorithm = { > > + .master_xfer = rk3x_i2c_xfer, > > + .functionality = rk3x_i2c_func, > > +}; > > + > > +static int rk3x_i2c_probe(struct platform_device *pdev) > > +{ > > + struct device_node *np = pdev->dev.of_node; > > + struct rk3x_i2c *i2c; > > + struct resource *mem; > > + int ret = 0; > > + > > + if (!pdev->dev.of_node) { > > + dev_err(&pdev->dev, "rk3x-i2c needs a devicetree node\n"); > > + return -EINVAL; > > + } > > + > > + i2c = devm_kzalloc(&pdev->dev, sizeof(struct rk3x_i2c), GFP_KERNEL); > > + if (!i2c) { > > + dev_err(&pdev->dev, "Could not alloc driver memory\n"); k*alloc already generate an error message of their own > > + return -ENOMEM; > > + } > > + > > + if (of_property_read_u32(pdev->dev.of_node, "rockchip,bus-index", > > + &i2c->bus_index)) { > > + dev_err(&pdev->dev, > > + "rk3x-i2c requires 'rockchip,bus-index' property\n"); > > + return -EINVAL; > > + } > > + > > + if (of_property_read_u32(pdev->dev.of_node, "clock-frequency", > > + &i2c->scl_frequency)) { > > + i2c->scl_frequency = 100 * 1000; > > + dev_info(&pdev->dev, "using default SCL frequency: 100kHz\n"); > > + } > > + > > + strlcpy(i2c->adap.name, "rk3x-i2c", sizeof(i2c->adap.name)); > > + i2c->adap.owner = THIS_MODULE; > > + i2c->adap.algo = &rk3x_i2c_algorithm; > > + i2c->adap.retries = 3; > > + i2c->adap.dev.of_node = np; > > + i2c->adap.algo_data = i2c; > > + i2c->adap.dev.parent = &pdev->dev; > > + > > + i2c->dev = &pdev->dev; > > + > > + spin_lock_init(&i2c->lock); > > + init_waitqueue_head(&i2c->wait); > > + > > + i2c->clk = devm_clk_get(&pdev->dev, 0); > > + if (IS_ERR(i2c->clk)) { > > + dev_err(&pdev->dev, "cannot get clock\n"); > > + return -ENOENT; > > + } > > + > > + clk_prepare_enable(i2c->clk); this is missing error handling and could be done later in the probe if desired > > + > > + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); > > + i2c->regs = devm_ioremap_resource(&pdev->dev, mem); > > + if (IS_ERR(i2c->regs)) { > > + ret = PTR_ERR(i2c->regs); > > + goto err_clk; > > + } > > + > > + /* Enable the I2C bus in the SOC general register file */ > > + i2c->grf = syscon_regmap_lookup_by_phandle(np, "rockchip,grf"); > > + if (IS_ERR(i2c->grf)) { > > + dev_err(&pdev->dev, > > + "rk3x-i2c requires a 'rockchip,grf' property\n"); > > + ret = PTR_ERR(i2c->grf); > > + goto err_clk; > > + } > > + > > + ret = rk3x_i2c_set_grf_enable(i2c, true); > > + if (ret != 0) { > > + dev_err(&pdev->dev, "could not enable I2C adapter in GRF: %d\n", > > + ret); > > + ret = -EIO; > > + goto err_clk; > > + } > > + > > + /* IRQ setup */ > > + i2c->irq = ret = platform_get_irq(pdev, 0); > > + if (ret <= 0) { > > + dev_err(&pdev->dev, "cannot find rk3x IRQ\n"); > > + ret = -EINVAL; > > + goto err_grf; > > + } > > + > > + ret = devm_request_irq(&pdev->dev, i2c->irq, rk3x_i2c_irq, > > + 0, dev_name(&pdev->dev), i2c); > > + if (ret != 0) { > > + dev_err(&pdev->dev, "cannot request IRQ\n"); > > + goto err_grf; > > + } > > + > > + platform_set_drvdata(pdev, i2c); > > + > > + if (i2c_add_adapter(&i2c->adap) != 0) { > > + pr_err("rk3x-i2c: Could not register adapter\n"); > > + goto err_grf; > > + } > > + > > + dev_info(&pdev->dev, "Initialized RK3xxx I2C bus at 0x%08x\n", > > + (unsigned int)i2c->regs); > > + > > + clk_disable(i2c->clk); > > + return 0; > > + > > +err_grf: > > + rk3x_i2c_set_grf_enable(i2c, false); I don't think we need to turn the switch back, as the grf setting is switching between an old and our new i2c controller implementation and we don't even know which state it was in beforehand. Therefore I'd expect an implementation of the old IP to set the bit itself - but I very much doubt we'll see one at all :-) Same for remove. > > +err_clk: > > + clk_disable_unprepare(i2c->clk); > > + return ret; > > +} > > + > > +static int rk3x_i2c_remove(struct platform_device *pdev) > > +{ > > + struct rk3x_i2c *i2c = platform_get_drvdata(pdev); > > + > > + rk3x_i2c_set_grf_enable(i2c, false); > > + > > + clk_unprepare(i2c->clk); > > + i2c_del_adapter(&i2c->adap); This should be switched, because only after i2c_del_adapter can you be sure that no i2c transaction is running any more Heiko > > + > > + return 0; > > +} > > + > > +static const struct of_device_id rk3x_i2c_match[] = { > > + { .compatible = "rockchip,rk3x-i2c" }, > > +}; > > + > > +static struct platform_driver rk3x_i2c_driver = { > > + .probe = rk3x_i2c_probe, > > + .remove = rk3x_i2c_remove, > > + .driver = { > > + .owner = THIS_MODULE, > > + .name = "rk3x-i2c", > > + .of_match_table = rk3x_i2c_match, > > + }, > > +}; > > + > > +module_platform_driver(rk3x_i2c_driver); > > + > > +MODULE_DESCRIPTION("Rockchip RK3xxx I2C Bus driver"); > > +MODULE_AUTHOR("Max Schwarz <max.schwarz@xxxxxxxxx>"); > > +MODULE_LICENSE("GPL v2"); -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
