| Message ID | 1458035482-14905-1-git-send-email-pandy.gao@nxp.com |
|---|---|
| State | Changes Requested |
| Headers | show |
Hello, On 15.03.2016 11:51, Gao Pan wrote: > Add i.MX7ULP i2c bus driver which can continue operating > in stop modes provided an appropriate clock is available. > > It is also designed for low CPU overhead with DMA offloading > of FIFO register accesses. > > Signed-off-by: Gao Pan <pandy.gao@nxp.com> > --- [snip] > + > +static int i2c_imx7ulp_start(struct imx7ulp_i2c_struct *i2c_imx7ulp) > +{ > + int ret; > + unsigned int temp; > + > + dev_dbg(&i2c_imx7ulp->adapter.dev, "<%s>\n", __func__); > + > + ret = clk_prepare_enable(i2c_imx7ulp->bus_clk); > + if (ret) { > + dev_err(&i2c_imx7ulp->adapter.dev, > + "can't enable I2C bus clock, ret=%d\n", ret); > + return ret; > + } > + > + ret = clk_prepare_enable(i2c_imx7ulp->per_clk); > + if (ret) { > + dev_err(&i2c_imx7ulp->adapter.dev, > + "can't enable I2C peripheral clock, ret=%d\n", ret); > + return ret; Leaked prepared/enabled i2c_imx7ulp->bus_clk clock on error path. > + } > + -- With best wishes, Vladimir -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Vladimir Zapolskiy <mailto:vladimir_zapolskiy@mentor.com> Sent: Tuesday, March 15, 2016 8:42 PM > To: Pan Gao <pandy.gao@nxp.com>; wsa@the-dreams.de; u.kleine- > koenig@pengutronix.de > Cc: linux-i2c@vger.kernel.org; Frank Li <frank.li@nxp.com>; Fugang Duan > <fugang.duan@nxp.com> > Subject: Re: [Patch v1] i2c: imx7ulp: add i.MX7ULP i2c controller bus driver > > Hello, > > On 15.03.2016 11:51, Gao Pan wrote: > > Add i.MX7ULP i2c bus driver which can continue operating in stop modes > > provided an appropriate clock is available. > > > > It is also designed for low CPU overhead with DMA offloading of FIFO > > register accesses. > > > > Signed-off-by: Gao Pan <pandy.gao@nxp.com> > > --- > > [snip] > > > + > > +static int i2c_imx7ulp_start(struct imx7ulp_i2c_struct *i2c_imx7ulp) > > +{ > > + int ret; > > + unsigned int temp; > > + > > + dev_dbg(&i2c_imx7ulp->adapter.dev, "<%s>\n", __func__); > > + > > + ret = clk_prepare_enable(i2c_imx7ulp->bus_clk); > > + if (ret) { > > + dev_err(&i2c_imx7ulp->adapter.dev, > > + "can't enable I2C bus clock, ret=%d\n", ret); > > + return ret; > > + } > > + > > + ret = clk_prepare_enable(i2c_imx7ulp->per_clk); > > + if (ret) { > > + dev_err(&i2c_imx7ulp->adapter.dev, > > + "can't enable I2C peripheral clock, ret=%d\n", ret); > > + return ret; > > Leaked prepared/enabled i2c_imx7ulp->bus_clk clock on error path. Yes, you are right. Thanks! Best Regards Gao Pan
From: Uwe Kleine-König <mailto:u.kleine-koenig@pengutronix.de> Sent: Tuesday, March 15, 2016 6:14 PM > To: Pan Gao <pandy.gao@nxp.com> > Cc: wsa@the-dreams.de; linux-i2c@vger.kernel.org; Frank Li > <frank.li@nxp.com>; Fugang Duan <fugang.duan@nxp.com> > Subject: Re: [Patch v1] i2c: imx7ulp: add i.MX7ULP i2c controller bus driver > > On Tue, Mar 15, 2016 at 05:51:22PM +0800, Gao Pan wrote: > > Add i.MX7ULP i2c bus driver which can continue operating in stop modes > > provided an appropriate clock is available. > > > > It is also designed for low CPU overhead with DMA offloading of FIFO > > register accesses. > > > > Signed-off-by: Gao Pan <pandy.gao@nxp.com> > > --- > > drivers/i2c/busses/Kconfig | 10 + > > drivers/i2c/busses/Makefile | 1 + > > drivers/i2c/busses/i2c-imx7ulp.c | 810 > > +++++++++++++++++++++++++++++++++++++++ > > 3 files changed, 821 insertions(+) > > > > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig > > index 0299dfa..9d3fee0 100644 > > --- a/drivers/i2c/busses/Kconfig > > +++ b/drivers/i2c/busses/Kconfig > > @@ -594,6 +594,16 @@ config I2C_IMX > > This driver can also be built as a module. If so, the module > > will be called i2c-imx. > > > > +config I2C_IMX7ULP > > + tristate "IMX7ULP I2C interface" > > + depends on ARCH_MXC > Is there a more specific symbol for i.MX7ULP than ARCH_MXC? > > I'd suggest to use: > > depends on ARCH_MXC || COMPILE_TEST > > I'm a bit irritated that this is not a dt driver. Thanks, I sent V1 for significant comments to optimize this patch. I will send V2 after validation. > > + help > > + Say Y here if you want to use the IIC bus controller on > > + the Freescale i.MX7ULP processors. > > + > > + This driver can also be built as a module. If so, the module > > + will be called i2c-imx7ulp. > > + > > config I2C_IOP3XX > > tristate "Intel IOPx3xx and IXP4xx on-chip I2C interface" > > depends on ARCH_IOP32X || ARCH_IOP33X || ARCH_IXP4XX || > ARCH_IOP13XX > > diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile > > index 37f2819..ef8607b 100644 > > --- a/drivers/i2c/busses/Makefile > > +++ b/drivers/i2c/busses/Makefile > > @@ -56,6 +56,7 @@ obj-$(CONFIG_I2C_HIX5HD2) += i2c-hix5hd2.o > > obj-$(CONFIG_I2C_IBM_IIC) += i2c-ibm_iic.o > > obj-$(CONFIG_I2C_IMG) += i2c-img-scb.o > > obj-$(CONFIG_I2C_IMX) += i2c-imx.o > > +obj-$(CONFIG_I2C_IMX7ULP) += i2c-imx7ulp.o > > obj-$(CONFIG_I2C_IOP3XX) += i2c-iop3xx.o > > obj-$(CONFIG_I2C_JZ4780) += i2c-jz4780.o > > obj-$(CONFIG_I2C_KEMPLD) += i2c-kempld.o > > diff --git a/drivers/i2c/busses/i2c-imx7ulp.c > > b/drivers/i2c/busses/i2c-imx7ulp.c > > new file mode 100644 > > index 0000000..bf4b1e8 > > --- /dev/null > > +++ b/drivers/i2c/busses/i2c-imx7ulp.c > > @@ -0,0 +1,810 @@ > > +/* > > + * This is i.MX7ULP low power i2c controller driver. > > + * > > + * Copyright 2016 Freescale Semiconductor, Inc. > > + * > > + * This program is free software; you can redistribute it and/or > > + * modify it under the terms of the GNU General Public License > > + * as published by the Free Software Foundation; either version 2 > > + * of the License, or (at your option) any later version. > > + * > > + * This program is distributed in the hope that it will be useful, > > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > > + * GNU General Public License for more details. > > + */ > > + > > +#include <linux/clk.h> > > +#include <linux/completion.h> > > +#include <linux/delay.h> > > +#include <linux/err.h> > > +#include <linux/errno.h> > > +#include <linux/i2c.h> > > +#include <linux/init.h> > > +#include <linux/interrupt.h> > > +#include <linux/io.h> > > +#include <linux/kernel.h> > > +#include <linux/module.h> > > +#include <linux/of.h> > > +#include <linux/of_device.h> > > +#include <linux/platform_data/i2c-imx.h> > > You don't make use of this one. Yes, Thanks. > > +#include <linux/platform_device.h> > > +#include <linux/sched.h> > > +#include <linux/slab.h> > > + > > +/* This will be the driver name the kernel reports */ #define > > +DRIVER_NAME "imx7ulp-i2c" > > + > > +/* IMX I2C registers */ > > +#define IMX7ULP_I2C_PARAM 0x04 /* i2c RX/TX FIFO size */ > > +#define IMX7ULP_I2C_MCR 0x10 /* i2c contrl register */ > > +#define IMX7ULP_I2C_MSR 0x14 /* i2c status register */ > > +#define IMX7ULP_I2C_MIER 0x18 /* i2c interrupt enable */ > > +#define IMX7ULP_I2C_MCFGR0 0x20 /* i2c master configuration */ > > +#define IMX7ULP_I2C_MCFGR1 0x24 /* i2c master configuration */ > > +#define IMX7ULP_I2C_MCFGR2 0x28 /* i2c master configuration */ > > +#define IMX7ULP_I2C_MCFGR3 0x2C /* i2c master configuration */ > > +#define IMX7ULP_I2C_MCCR0 0x48 /* i2c master clk configuration > */ > > +#define IMX7ULP_I2C_MCCR1 0x50 /* i2c master clk configuration > */ > > +#define IMX7ULP_I2C_MFCR 0x58 /* i2c master FIFO control */ > > +#define IMX7ULP_I2C_MFSR 0x5C /* i2c master FIFO status */ > > +#define IMX7ULP_I2C_MTDR 0x60 /* i2c master TX data register > */ > > +#define IMX7ULP_I2C_MRDR 0x70 /* i2c master RX data register > */ > > + > > + > > +/* i2c command data */ > > +#define TRAN_DATA 0X00 > > +#define RECV_DATA 0X01 > > +#define GEN_STOP 0X02 > > +#define RECV_DISCARD 0X03 > > +#define GEN_START 0X04 > > +#define START_NACK 0X05 > > +#define START_HIGH 0X06 > > +#define START_HIGH_NACK 0X07 > > + > > + > > +/* Bits of I2C controller registers */ > > +#define MCR_MEN 0X001 > > +#define MCR_RST 0X002 > > +#define MCR_DOZEN 0X004 > > +#define MCR_DBGEN 0X008 > > +#define MCR_RTF 0X100 > > +#define MCR_RRF 0X200 > > + > > +/* Bits of I2C status registers */ > > +#define MSR_TDF (1 << 0) > > +#define MSR_RDF (1 << 1) > > +#define MSR_NDF (1 << 10) > > +#define MSR_ALF (1 << 11) > > +#define MSR_MBF (1 << 24) > > +#define MSR_BBF (1 << 25) > > + > > +/* Bits of I2C interrupt enable registers */ > > +#define MIER_TDIE 0X0001 > > +#define MIER_RDIE 0X0002 > > +#define MIER_NDIE 0X0400 > > + > > +/* Bits of I2C MCFGR1 registers */ > > +#define MCFGR1_IGNACK 0X0200 > > + > > +#define FILTSDA_SHIFT 24 > > +#define FILTSCL_SHIFT 16 > > +#define DATAVD_SHIFT 24 > > +#define SETHOLD_SHIFT 16 > > +#define CLKHI_SHIFT 8 > > + > > +#define I2C_CLK_RATIO 2 > > +#define CHUNK_DATA 256 > > + > > +#define LPI2C_DEFAULT_RATE 100000 > > +#define STARDARD_MAX_BITRATE 400000 > > +#define FAST_MAX_BITRATE 1000000 > > +#define FAST_PLUS_MAX_BITRATE 3400000 > > +#define HIGHSPEED_MAX_BITRATE 5000000 > > + > > + > > +enum imx7ulp_i2c_mode { > > + STANDARD, /* 100+Kbps */ > > + FAST, /* 400+Kbps */ > > + FAST_PLUS, /* 1.0+Mbps */ > > + ULTRA_FAST, /* 5.0+Mbps */ > > + HS, /* 3.4+Mbps */ > > +}; > > + > > +enum imx7ulp_i2c_pincfg { > > + TWO_PIN_OD, /* 2-pin open drain mode */ > > + TWO_PIN_OO, /* 2-pin output only mode (utra-fast mode) */ > > + TWO_PIN_PP, /* 2-pin push-pull mode */ > > + FOUR_PIN_PP, /* 4-pin push-pull mode */ > > + TWO_PIN_OD_SS, /* 2-pin open drain mode with separate slave > */ > > + TWO_PIN_OO_SS, /* 2-pin output only mode with separate slave > */ > > + TWO_PIN_PP_SS, /* 2-pin push-pull mode with separate slave */ > > + FOUR_PIN_PP_IO, /* 4-pin push-pull mode (inverted output) */ > > +}; > > + > > +struct imx7ulp_i2c_modecfg { > > + u8 prescale; > > + u8 filtscl; > > + u8 filtsda; > > + u8 sethold; > > + u8 clklo; > > + u8 clkhi; > > + u8 datavd; > > +}; > > + > > +struct imx7ulp_i2c_struct { > > + struct i2c_adapter adapter; > > + struct clk *bus_clk; > > + struct clk *per_clk; > > + void __iomem *base; > > + wait_queue_head_t queue; > > + unsigned long msr; > > + __u8 *rx_buf; > > + __u8 *tx_buf; > > + unsigned int rx_water; > > + unsigned int tx_water; > > + unsigned int msg_len; > > + unsigned int rx_len; > > + unsigned int tx_len; > > + unsigned int msg_done; > > + unsigned int block_data; > > + unsigned int rxfifo_size; > > + unsigned int txfifo_size; > > + unsigned int bitrate; > > + enum imx7ulp_i2c_mode mode; > > +}; > > + > > +static inline void imx7ulp_i2c_write_reg(unsigned int val, > > + struct imx7ulp_i2c_struct *i2c_imx7ulp, unsigned int reg) { > > + writel(val, i2c_imx7ulp->base + reg); } > > + > > +static inline unsigned int imx7ulp_i2c_read_reg( > > + struct imx7ulp_i2c_struct *i2c_imx7ulp, unsigned int reg) { > > + return readl(i2c_imx7ulp->base + reg); } > > + > > +static int i2c_imx7ulp_bus_busy( > > + struct imx7ulp_i2c_struct *i2c_imx7ulp, int for_busy) { > > + unsigned long orig_jiffies = jiffies; > > + unsigned int temp; > > + > > + dev_dbg(&i2c_imx7ulp->adapter.dev, "<%s>\n", __func__); > > + > > + while (1) { > > + temp = imx7ulp_i2c_read_reg(i2c_imx7ulp, > IMX7ULP_I2C_MSR); > > + > > + /* check for arbitration lost, clear if set */ > > + if (temp & MSR_ALF) { > > + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, > IMX7ULP_I2C_MSR); > > + return -EAGAIN; > > + } > > + > > + if (for_busy && (temp & MSR_BBF)) > > + break; > > + if (!for_busy && !(temp & MSR_BBF)) > > + break; > > + if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) { > > + dev_dbg(&i2c_imx7ulp->adapter.dev, > > + "<%s> I2C bus is busy\n", __func__); > > + return -ETIMEDOUT; > > + } > > + schedule(); > > + } > > + > > + return 0; > > +} > > + > > +static void i2c_imx7ulp_set_mode(struct imx7ulp_i2c_struct > > +*i2c_imx7ulp) { > > + enum imx7ulp_i2c_mode mode; > > + unsigned int bitrate = i2c_imx7ulp->bitrate; > > + > > + if (bitrate < STARDARD_MAX_BITRATE) > > + mode = STANDARD; > > + else if (bitrate < FAST_MAX_BITRATE) > > + mode = FAST; > > + else if (bitrate < FAST_PLUS_MAX_BITRATE) > > + mode = FAST_PLUS; > > + else if (bitrate < HIGHSPEED_MAX_BITRATE) > > + mode = HS; > > + else > > + mode = ULTRA_FAST; > > + > > + i2c_imx7ulp->mode = mode; > > + > > + dev_dbg(&i2c_imx7ulp->adapter.dev, "I2C MODE = %d\n", mode); } > > + > > +/* CLKLO = I2C_CLK_RATIO * CLKHI, SETHOLD = CLKHI, DATAVD = CLKHI/2 > > +*/ static void i2c_imx7ulp_set_bitrate(struct imx7ulp_i2c_struct > > +*i2c_imx7ulp) { > > + unsigned int per_clk_rate; > > + unsigned int clk_high, clk_low, clk_cycle; > > + unsigned int temp; > > + struct imx7ulp_i2c_modecfg modecfg; > > + > > + per_clk_rate = clk_get_rate(i2c_imx7ulp->per_clk); > > + > > + /* filtsda/filtscl = 0 in high speed mode */ > > + if (i2c_imx7ulp->mode == HS || i2c_imx7ulp->mode == ULTRA_FAST) > > + modecfg.filtscl = modecfg.filtsda = 0; > > + else > > + modecfg.filtscl = modecfg.filtsda = 2; > > + > > + clk_cycle = per_clk_rate / (2 * i2c_imx7ulp->bitrate) - 3 > > + - (modecfg.filtscl >> 1); > > + clk_high = (clk_cycle + I2C_CLK_RATIO) / (I2C_CLK_RATIO + 1); > > + clk_low = clk_cycle - clk_high; > > + > > + modecfg.prescale = 1; > > + modecfg.sethold = clk_high; > > + modecfg.clklo = clk_low; > > + modecfg.clkhi = clk_high; > > + modecfg.datavd = clk_high >> 1; > > + > > + temp = modecfg.prescale; > > + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MCFGR1); > > + > > + temp = modecfg.filtscl << FILTSCL_SHIFT | > > + modecfg.filtsda << FILTSDA_SHIFT; > > + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MCFGR2); > > + > > + temp = modecfg.datavd << DATAVD_SHIFT | > > + modecfg.sethold << SETHOLD_SHIFT; > > + temp |= modecfg.clkhi << CLKHI_SHIFT | modecfg.clklo; > > + > > + /* IMX7ULP_I2C_MCCR1 used for HS mode */ > > + if (i2c_imx7ulp->mode == HS) > > + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, > IMX7ULP_I2C_MCCR1); > > + else > > + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, > IMX7ULP_I2C_MCCR0); } > > + > > +static void i2c_imx7ulp_set_pincfg(struct imx7ulp_i2c_struct > > +*i2c_imx7ulp) { > > + unsigned int temp = 0; > > + enum imx7ulp_i2c_pincfg pincfg; > > + enum imx7ulp_i2c_mode mode = i2c_imx7ulp->mode; > > + > > + if (mode == ULTRA_FAST) > > + pincfg = TWO_PIN_OO; > > + else > > + pincfg = TWO_PIN_OD; > > + > > + temp = imx7ulp_i2c_read_reg(i2c_imx7ulp, IMX7ULP_I2C_MCFGR1); > > + temp |= pincfg << 24; > > + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MCFGR1); } > > + > > +static int i2c_imx7ulp_tx_addr(struct imx7ulp_i2c_struct *i2c_imx7ulp, > > + struct i2c_msg *msgs, u8 read) > > +{ > > + unsigned int temp; > > + > > + /* 10 bit addressing(B1:11110A9A8R/W, B0:A7-A0)*/ > > + if (msgs->flags & I2C_M_TEN) { > > + temp = (msgs->addr & 0x300) >> 7; > > + temp |= read | (GEN_START << 8); > > + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, > IMX7ULP_I2C_MTDR); > > + > > + temp = msgs->addr & 0xff; > > + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, > IMX7ULP_I2C_MTDR); > > + } else { > > + temp = (msgs->addr << 1 | read) | (GEN_START << 8); > > + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, > IMX7ULP_I2C_MTDR); > > + } > > + > > + return i2c_imx7ulp_bus_busy(i2c_imx7ulp, 1); } > > + > > +static int i2c_imx7ulp_start(struct imx7ulp_i2c_struct *i2c_imx7ulp) > > +{ > > + int ret; > > + unsigned int temp; > > + > > + dev_dbg(&i2c_imx7ulp->adapter.dev, "<%s>\n", __func__); > > + > > + ret = clk_prepare_enable(i2c_imx7ulp->bus_clk); > > + if (ret) { > > + dev_err(&i2c_imx7ulp->adapter.dev, > > + "can't enable I2C bus clock, ret=%d\n", ret); > > + return ret; > > + } > > + > > + ret = clk_prepare_enable(i2c_imx7ulp->per_clk); > > + if (ret) { > > + dev_err(&i2c_imx7ulp->adapter.dev, > > + "can't enable I2C peripheral clock, ret=%d\n", ret); > > + return ret; > > + } > > + > > + /* mater logic register reset */ > > master? Yes, thanks. > > + temp = imx7ulp_i2c_read_reg(i2c_imx7ulp, IMX7ULP_I2C_MCR); > > + temp |= MCR_RST; > > + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MCR); > > [...] > > +static int i2c_imx7ulp_xfer(struct i2c_adapter *adapter, > > + struct i2c_msg *msgs, int num) > > +{ > > + unsigned int i; > > + int result; > > + struct imx7ulp_i2c_struct *i2c_imx7ulp = i2c_get_adapdata(adapter); > > + > > +#ifdef CONFIG_I2C_DEBUG_BUS > > + unsigned int temp; > > +#endif > > This can be local to the for loop below Thanks. > > + > > + dev_dbg(&i2c_imx7ulp->adapter.dev, "<%s>\n", __func__); > > + > > + result = i2c_imx7ulp_start(i2c_imx7ulp); > > + if (result) > > + return result; > > + > > + /* read/write data */ > > + for (i = 0; i < num; i++) { > > + dev_dbg(&i2c_imx7ulp->adapter.dev, > > + "<%s> transfer message: %d\n", __func__, i); > > + > > +#ifdef CONFIG_I2C_DEBUG_BUS > > + temp = imx7ulp_i2c_read_reg(i2c_imx7ulp, > IMX7ULP_I2C_MCR); > > + dev_dbg(&i2c_imx7ulp->adapter.dev, > > + "<%s> CONTROL: MEN=%d, RST=%d, DOZEN=%d, > DBGEN=%d, RTF=%d, RRF=%d\n", > > + __func__, > > + (temp & MCR_MEN ? 1 : 0), (temp & MCR_RST ? 1 : 0), > > + (temp & MCR_DOZEN ? 1 : 0), (temp & MCR_DBGEN ? > 1 : 0), > > + (temp & MCR_RTF ? 1 : 0), (temp & MCR_RRF ? 1 : 0)); > > Maybe it's easier and more useful to just print out the register value instead of > decoding it here? Yes, you are right. Thanks. > > +#endif > > + > > + if (msgs[i].flags & I2C_M_RD) > > + result = i2c_imx7ulp_read(i2c_imx7ulp, &msgs[i]); > > + else > > + result = i2c_imx7ulp_write(i2c_imx7ulp, &msgs[i]); > > + if (result) > > + goto fail0; > > + } > > [...] > > +static int i2c_imx7ulp_probe(struct platform_device *pdev) { > > + struct imx7ulp_i2c_struct *i2c_imx7ulp; > > + struct resource *res; > > + void __iomem *base; > > + int irq, ret; > > + unsigned int temp; > > + > > + irq = platform_get_irq(pdev, 0); > > + if (irq < 0) { > > + dev_err(&pdev->dev, "can't get irq number\n"); > > + return irq; > > + } > > + > > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > > + base = devm_ioremap_resource(&pdev->dev, res); > > + if (IS_ERR(base)) > > + return PTR_ERR(base); > > + > > + i2c_imx7ulp = devm_kzalloc(&pdev->dev, > > + sizeof(*i2c_imx7ulp), GFP_KERNEL); > > + if (!i2c_imx7ulp) > > + return -ENOMEM; > > + > > + /* Setup i2c_imx7ulp driver structure */ > > + strlcpy(i2c_imx7ulp->adapter.name, pdev->name, > > + sizeof(i2c_imx7ulp->adapter.name)); > > + i2c_imx7ulp->adapter.owner = THIS_MODULE; > > + i2c_imx7ulp->adapter.algo = &i2c_imx7ulp_algo; > > + i2c_imx7ulp->adapter.dev.parent = &pdev->dev; > > + i2c_imx7ulp->adapter.nr = pdev->id; > > + i2c_imx7ulp->base = base; > > + i2c_imx7ulp->adapter.dev.of_node = pdev->dev.of_node; > > + > > + /* Get I2C bus clock */ > > + i2c_imx7ulp->bus_clk = devm_clk_get(&pdev->dev, "bus_clk"); > > + if (IS_ERR(i2c_imx7ulp->bus_clk)) { > > + dev_err(&pdev->dev, "can't get I2C bus clock\n"); > > + return PTR_ERR(i2c_imx7ulp->bus_clk); > > + } > > + > > + /* Get I2C peripheral clock */ > > + i2c_imx7ulp->per_clk = devm_clk_get(&pdev->dev, "per_clk"); > > + if (IS_ERR(i2c_imx7ulp->per_clk)) { > > + dev_err(&pdev->dev, "can't get I2C peripheral clock\n"); > > + return PTR_ERR(i2c_imx7ulp->per_clk); > > + } > > + > > + ret = clk_prepare_enable(i2c_imx7ulp->bus_clk); > > + if (ret) { > > + dev_err(&pdev->dev, > > + "can't enable I2C bus clock, ret=%d\n", ret); > > + return ret; > > + } > > + > > + /* Request IRQ */ > > + ret = devm_request_irq(&pdev->dev, irq, i2c_imx7ulp_isr, 0, > > + pdev->name, i2c_imx7ulp); > > + if (ret) { > > + dev_err(&pdev->dev, "can't claim irq %d\n", irq); > > + goto clk_disable; > > + } > > I think the irq should be requested later unless you ensure the irq cannot trigger > until all the initializing below is complete. (And even then it might be cleaner.) Thanks, will fix it the next version. > > + > > + /* Init queue */ > > + init_waitqueue_head(&i2c_imx7ulp->queue); > > + > > + /* Set up adapter data */ > > + i2c_set_adapdata(&i2c_imx7ulp->adapter, i2c_imx7ulp); > > + > > + /* Set up platform driver data */ > > + platform_set_drvdata(pdev, i2c_imx7ulp); > > + > > + /* Read i2c fifosize parameter, unit: words */ > > + temp = imx7ulp_i2c_read_reg(i2c_imx7ulp, IMX7ULP_I2C_PARAM); > > + i2c_imx7ulp->txfifo_size = 1 << (temp & 0X000F); > > + i2c_imx7ulp->rxfifo_size = 1 << (temp & 0X0F00); > > + > > + ret = of_property_read_u32(pdev->dev.of_node, > > + "clock-frequency", &i2c_imx7ulp->bitrate); > > + if (ret) > > + i2c_imx7ulp->bitrate = LPI2C_DEFAULT_RATE; > > + > > + /*i2c imx7ulp basic config */ > > + i2c_imx7ulp_set_mode(i2c_imx7ulp); > > + i2c_imx7ulp_set_bitrate(i2c_imx7ulp); > > + i2c_imx7ulp_set_pincfg(i2c_imx7ulp); > > + > > + /* Add I2C adapter */ > > + ret = i2c_add_numbered_adapter(&i2c_imx7ulp->adapter); > > + if (ret) { > > + dev_err(&pdev->dev, "registration failed\n"); > > + goto clk_disable; > > + } > > + > > + dev_dbg(&i2c_imx7ulp->adapter.dev, "claimed irq %d\n", irq); > > + dev_dbg(&i2c_imx7ulp->adapter.dev, "device resources: %pR\n", res); > > + dev_dbg(&i2c_imx7ulp->adapter.dev, "adapter name: \"%s\"\n", > > + i2c_imx7ulp->adapter.name); > > + dev_info(&i2c_imx7ulp->adapter.dev, "IMX I2C adapter registered\n"); > > + > > +clk_disable: > > + clk_disable_unprepare(i2c_imx7ulp->bus_clk); > > + return ret; > > +} > > + > > +static int i2c_imx7ulp_remove(struct platform_device *pdev) { > > + struct imx7ulp_i2c_struct *i2c_imx7ulp = platform_get_drvdata(pdev); > > + > > + i2c_del_adapter(&i2c_imx7ulp->adapter); > > + clk_disable_unprepare(i2c_imx7ulp->bus_clk); > > + clk_disable_unprepare(i2c_imx7ulp->per_clk); > > After probe the busclk is unprepared already. Do these call balance correctly > here? Thanks, these calls are unnecessary here, will fix it the next version. Best Regards Gao Pan -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Mar 15, 2016 at 05:51:22PM +0800, Gao Pan wrote: > Add i.MX7ULP i2c bus driver which can continue operating > in stop modes provided an appropriate clock is available. > > It is also designed for low CPU overhead with DMA offloading > of FIFO register accesses. > > Signed-off-by: Gao Pan <pandy.gao@nxp.com> Since you need to resend anyhow (DT support?), just a few high-level things. There is a lot of dev_dbg in here. Some of them are helpful when developing the driver, but not anymore once the driver is upstream. Please check for that. > +static int __init i2c_adap_imx_init(void) > +{ > + return platform_driver_register(&i2c_imx7ulp_driver); > +} > +subsys_initcall(i2c_adap_imx_init); I usually don't accept subsys_initcall() for new drivers anymore. It usually works around problems. Make sure your I2C clients do defer probing properly.
From: Wolfram Sang <wsa@the-dreams.de> Sent: Sunday, April 17, 2016 5:29 AM > To: Pan Gao <pandy.gao@nxp.com> > Cc: u.kleine-koenig@pengutronix.de; linux-i2c@vger.kernel.org; Frank Li > <frank.li@nxp.com>; Fugang Duan <fugang.duan@nxp.com> > Subject: Re: [Patch v1] i2c: imx7ulp: add i.MX7ULP i2c controller bus driver > > On Tue, Mar 15, 2016 at 05:51:22PM +0800, Gao Pan wrote: > > Add i.MX7ULP i2c bus driver which can continue operating in stop modes > > provided an appropriate clock is available. > > > > It is also designed for low CPU overhead with DMA offloading of FIFO > > register accesses. > > > > Signed-off-by: Gao Pan <pandy.gao@nxp.com> > > Since you need to resend anyhow (DT support?), just a few high-level things. > Yes, I will send DT patch in the V2. > There is a lot of dev_dbg in here. Some of them are helpful when developing > the driver, but not anymore once the driver is upstream. Ok, will change it in V2. Thanks. > Please check for that. > > > +static int __init i2c_adap_imx_init(void) { > > + return platform_driver_register(&i2c_imx7ulp_driver); > > +} > > +subsys_initcall(i2c_adap_imx_init); > > I usually don't accept subsys_initcall() for new drivers anymore. It usually > works around problems. Make sure your I2C clients do defer probing properly. Will change it in V2. Thanks. Thanks. Pandy. -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 0299dfa..9d3fee0 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -594,6 +594,16 @@ config I2C_IMX This driver can also be built as a module. If so, the module will be called i2c-imx. +config I2C_IMX7ULP + tristate "IMX7ULP I2C interface" + depends on ARCH_MXC + help + Say Y here if you want to use the IIC bus controller on + the Freescale i.MX7ULP processors. + + This driver can also be built as a module. If so, the module + will be called i2c-imx7ulp. + config I2C_IOP3XX tristate "Intel IOPx3xx and IXP4xx on-chip I2C interface" depends on ARCH_IOP32X || ARCH_IOP33X || ARCH_IXP4XX || ARCH_IOP13XX diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 37f2819..ef8607b 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -56,6 +56,7 @@ obj-$(CONFIG_I2C_HIX5HD2) += i2c-hix5hd2.o obj-$(CONFIG_I2C_IBM_IIC) += i2c-ibm_iic.o obj-$(CONFIG_I2C_IMG) += i2c-img-scb.o obj-$(CONFIG_I2C_IMX) += i2c-imx.o +obj-$(CONFIG_I2C_IMX7ULP) += i2c-imx7ulp.o obj-$(CONFIG_I2C_IOP3XX) += i2c-iop3xx.o obj-$(CONFIG_I2C_JZ4780) += i2c-jz4780.o obj-$(CONFIG_I2C_KEMPLD) += i2c-kempld.o diff --git a/drivers/i2c/busses/i2c-imx7ulp.c b/drivers/i2c/busses/i2c-imx7ulp.c new file mode 100644 index 0000000..bf4b1e8 --- /dev/null +++ b/drivers/i2c/busses/i2c-imx7ulp.c @@ -0,0 +1,810 @@ +/* + * This is i.MX7ULP low power i2c controller driver. + * + * Copyright 2016 Freescale Semiconductor, Inc. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/clk.h> +#include <linux/completion.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/errno.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/platform_data/i2c-imx.h> +#include <linux/platform_device.h> +#include <linux/sched.h> +#include <linux/slab.h> + +/* This will be the driver name the kernel reports */ +#define DRIVER_NAME "imx7ulp-i2c" + +/* IMX I2C registers */ +#define IMX7ULP_I2C_PARAM 0x04 /* i2c RX/TX FIFO size */ +#define IMX7ULP_I2C_MCR 0x10 /* i2c contrl register */ +#define IMX7ULP_I2C_MSR 0x14 /* i2c status register */ +#define IMX7ULP_I2C_MIER 0x18 /* i2c interrupt enable */ +#define IMX7ULP_I2C_MCFGR0 0x20 /* i2c master configuration */ +#define IMX7ULP_I2C_MCFGR1 0x24 /* i2c master configuration */ +#define IMX7ULP_I2C_MCFGR2 0x28 /* i2c master configuration */ +#define IMX7ULP_I2C_MCFGR3 0x2C /* i2c master configuration */ +#define IMX7ULP_I2C_MCCR0 0x48 /* i2c master clk configuration */ +#define IMX7ULP_I2C_MCCR1 0x50 /* i2c master clk configuration */ +#define IMX7ULP_I2C_MFCR 0x58 /* i2c master FIFO control */ +#define IMX7ULP_I2C_MFSR 0x5C /* i2c master FIFO status */ +#define IMX7ULP_I2C_MTDR 0x60 /* i2c master TX data register */ +#define IMX7ULP_I2C_MRDR 0x70 /* i2c master RX data register */ + + +/* i2c command data */ +#define TRAN_DATA 0X00 +#define RECV_DATA 0X01 +#define GEN_STOP 0X02 +#define RECV_DISCARD 0X03 +#define GEN_START 0X04 +#define START_NACK 0X05 +#define START_HIGH 0X06 +#define START_HIGH_NACK 0X07 + + +/* Bits of I2C controller registers */ +#define MCR_MEN 0X001 +#define MCR_RST 0X002 +#define MCR_DOZEN 0X004 +#define MCR_DBGEN 0X008 +#define MCR_RTF 0X100 +#define MCR_RRF 0X200 + +/* Bits of I2C status registers */ +#define MSR_TDF (1 << 0) +#define MSR_RDF (1 << 1) +#define MSR_NDF (1 << 10) +#define MSR_ALF (1 << 11) +#define MSR_MBF (1 << 24) +#define MSR_BBF (1 << 25) + +/* Bits of I2C interrupt enable registers */ +#define MIER_TDIE 0X0001 +#define MIER_RDIE 0X0002 +#define MIER_NDIE 0X0400 + +/* Bits of I2C MCFGR1 registers */ +#define MCFGR1_IGNACK 0X0200 + +#define FILTSDA_SHIFT 24 +#define FILTSCL_SHIFT 16 +#define DATAVD_SHIFT 24 +#define SETHOLD_SHIFT 16 +#define CLKHI_SHIFT 8 + +#define I2C_CLK_RATIO 2 +#define CHUNK_DATA 256 + +#define LPI2C_DEFAULT_RATE 100000 +#define STARDARD_MAX_BITRATE 400000 +#define FAST_MAX_BITRATE 1000000 +#define FAST_PLUS_MAX_BITRATE 3400000 +#define HIGHSPEED_MAX_BITRATE 5000000 + + +enum imx7ulp_i2c_mode { + STANDARD, /* 100+Kbps */ + FAST, /* 400+Kbps */ + FAST_PLUS, /* 1.0+Mbps */ + ULTRA_FAST, /* 5.0+Mbps */ + HS, /* 3.4+Mbps */ +}; + +enum imx7ulp_i2c_pincfg { + TWO_PIN_OD, /* 2-pin open drain mode */ + TWO_PIN_OO, /* 2-pin output only mode (utra-fast mode) */ + TWO_PIN_PP, /* 2-pin push-pull mode */ + FOUR_PIN_PP, /* 4-pin push-pull mode */ + TWO_PIN_OD_SS, /* 2-pin open drain mode with separate slave */ + TWO_PIN_OO_SS, /* 2-pin output only mode with separate slave */ + TWO_PIN_PP_SS, /* 2-pin push-pull mode with separate slave */ + FOUR_PIN_PP_IO, /* 4-pin push-pull mode (inverted output) */ +}; + +struct imx7ulp_i2c_modecfg { + u8 prescale; + u8 filtscl; + u8 filtsda; + u8 sethold; + u8 clklo; + u8 clkhi; + u8 datavd; +}; + +struct imx7ulp_i2c_struct { + struct i2c_adapter adapter; + struct clk *bus_clk; + struct clk *per_clk; + void __iomem *base; + wait_queue_head_t queue; + unsigned long msr; + __u8 *rx_buf; + __u8 *tx_buf; + unsigned int rx_water; + unsigned int tx_water; + unsigned int msg_len; + unsigned int rx_len; + unsigned int tx_len; + unsigned int msg_done; + unsigned int block_data; + unsigned int rxfifo_size; + unsigned int txfifo_size; + unsigned int bitrate; + enum imx7ulp_i2c_mode mode; +}; + +static inline void imx7ulp_i2c_write_reg(unsigned int val, + struct imx7ulp_i2c_struct *i2c_imx7ulp, unsigned int reg) +{ + writel(val, i2c_imx7ulp->base + reg); +} + +static inline unsigned int imx7ulp_i2c_read_reg( + struct imx7ulp_i2c_struct *i2c_imx7ulp, unsigned int reg) +{ + return readl(i2c_imx7ulp->base + reg); +} + +static int i2c_imx7ulp_bus_busy( + struct imx7ulp_i2c_struct *i2c_imx7ulp, int for_busy) +{ + unsigned long orig_jiffies = jiffies; + unsigned int temp; + + dev_dbg(&i2c_imx7ulp->adapter.dev, "<%s>\n", __func__); + + while (1) { + temp = imx7ulp_i2c_read_reg(i2c_imx7ulp, IMX7ULP_I2C_MSR); + + /* check for arbitration lost, clear if set */ + if (temp & MSR_ALF) { + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MSR); + return -EAGAIN; + } + + if (for_busy && (temp & MSR_BBF)) + break; + if (!for_busy && !(temp & MSR_BBF)) + break; + if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) { + dev_dbg(&i2c_imx7ulp->adapter.dev, + "<%s> I2C bus is busy\n", __func__); + return -ETIMEDOUT; + } + schedule(); + } + + return 0; +} + +static void i2c_imx7ulp_set_mode(struct imx7ulp_i2c_struct *i2c_imx7ulp) +{ + enum imx7ulp_i2c_mode mode; + unsigned int bitrate = i2c_imx7ulp->bitrate; + + if (bitrate < STARDARD_MAX_BITRATE) + mode = STANDARD; + else if (bitrate < FAST_MAX_BITRATE) + mode = FAST; + else if (bitrate < FAST_PLUS_MAX_BITRATE) + mode = FAST_PLUS; + else if (bitrate < HIGHSPEED_MAX_BITRATE) + mode = HS; + else + mode = ULTRA_FAST; + + i2c_imx7ulp->mode = mode; + + dev_dbg(&i2c_imx7ulp->adapter.dev, "I2C MODE = %d\n", mode); +} + +/* CLKLO = I2C_CLK_RATIO * CLKHI, SETHOLD = CLKHI, DATAVD = CLKHI/2 */ +static void i2c_imx7ulp_set_bitrate(struct imx7ulp_i2c_struct *i2c_imx7ulp) +{ + unsigned int per_clk_rate; + unsigned int clk_high, clk_low, clk_cycle; + unsigned int temp; + struct imx7ulp_i2c_modecfg modecfg; + + per_clk_rate = clk_get_rate(i2c_imx7ulp->per_clk); + + /* filtsda/filtscl = 0 in high speed mode */ + if (i2c_imx7ulp->mode == HS || i2c_imx7ulp->mode == ULTRA_FAST) + modecfg.filtscl = modecfg.filtsda = 0; + else + modecfg.filtscl = modecfg.filtsda = 2; + + clk_cycle = per_clk_rate / (2 * i2c_imx7ulp->bitrate) - 3 + - (modecfg.filtscl >> 1); + clk_high = (clk_cycle + I2C_CLK_RATIO) / (I2C_CLK_RATIO + 1); + clk_low = clk_cycle - clk_high; + + modecfg.prescale = 1; + modecfg.sethold = clk_high; + modecfg.clklo = clk_low; + modecfg.clkhi = clk_high; + modecfg.datavd = clk_high >> 1; + + temp = modecfg.prescale; + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MCFGR1); + + temp = modecfg.filtscl << FILTSCL_SHIFT | + modecfg.filtsda << FILTSDA_SHIFT; + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MCFGR2); + + temp = modecfg.datavd << DATAVD_SHIFT | + modecfg.sethold << SETHOLD_SHIFT; + temp |= modecfg.clkhi << CLKHI_SHIFT | modecfg.clklo; + + /* IMX7ULP_I2C_MCCR1 used for HS mode */ + if (i2c_imx7ulp->mode == HS) + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MCCR1); + else + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MCCR0); +} + +static void i2c_imx7ulp_set_pincfg(struct imx7ulp_i2c_struct *i2c_imx7ulp) +{ + unsigned int temp = 0; + enum imx7ulp_i2c_pincfg pincfg; + enum imx7ulp_i2c_mode mode = i2c_imx7ulp->mode; + + if (mode == ULTRA_FAST) + pincfg = TWO_PIN_OO; + else + pincfg = TWO_PIN_OD; + + temp = imx7ulp_i2c_read_reg(i2c_imx7ulp, IMX7ULP_I2C_MCFGR1); + temp |= pincfg << 24; + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MCFGR1); +} + +static int i2c_imx7ulp_tx_addr(struct imx7ulp_i2c_struct *i2c_imx7ulp, + struct i2c_msg *msgs, u8 read) +{ + unsigned int temp; + + /* 10 bit addressing(B1:11110A9A8R/W, B0:A7-A0)*/ + if (msgs->flags & I2C_M_TEN) { + temp = (msgs->addr & 0x300) >> 7; + temp |= read | (GEN_START << 8); + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MTDR); + + temp = msgs->addr & 0xff; + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MTDR); + } else { + temp = (msgs->addr << 1 | read) | (GEN_START << 8); + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MTDR); + } + + return i2c_imx7ulp_bus_busy(i2c_imx7ulp, 1); +} + +static int i2c_imx7ulp_start(struct imx7ulp_i2c_struct *i2c_imx7ulp) +{ + int ret; + unsigned int temp; + + dev_dbg(&i2c_imx7ulp->adapter.dev, "<%s>\n", __func__); + + ret = clk_prepare_enable(i2c_imx7ulp->bus_clk); + if (ret) { + dev_err(&i2c_imx7ulp->adapter.dev, + "can't enable I2C bus clock, ret=%d\n", ret); + return ret; + } + + ret = clk_prepare_enable(i2c_imx7ulp->per_clk); + if (ret) { + dev_err(&i2c_imx7ulp->adapter.dev, + "can't enable I2C peripheral clock, ret=%d\n", ret); + return ret; + } + + /* mater logic register reset */ + temp = imx7ulp_i2c_read_reg(i2c_imx7ulp, IMX7ULP_I2C_MCR); + temp |= MCR_RST; + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MCR); + + if (i2c_imx7ulp->mode == ULTRA_FAST) { + temp = imx7ulp_i2c_read_reg(i2c_imx7ulp, IMX7ULP_I2C_MCFGR1); + temp |= MCFGR1_IGNACK; + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MCFGR1); + } + + /* enable master, clear TX/RX FIFO */ + temp = imx7ulp_i2c_read_reg(i2c_imx7ulp, IMX7ULP_I2C_MCR); + temp |= MCR_MEN | MCR_RRF | MCR_RTF; + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MCR); + + return 0; +} + +static void i2c_imx7ulp_stop(struct imx7ulp_i2c_struct *i2c_imx7ulp) +{ + unsigned int temp = 0; + + dev_dbg(&i2c_imx7ulp->adapter.dev, "<%s>\n", __func__); + + /* generate stop */ + temp = GEN_STOP << 8; + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MTDR); + + /* disable master */ + temp = imx7ulp_i2c_read_reg(i2c_imx7ulp, IMX7ULP_I2C_MCR); + temp &= ~MCR_MEN; + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MCR); + + i2c_imx7ulp_bus_busy(i2c_imx7ulp, 0); + + clk_disable_unprepare(i2c_imx7ulp->bus_clk); + clk_disable_unprepare(i2c_imx7ulp->per_clk); +} + +static int i2c_imx7ulp_msg_complete(struct imx7ulp_i2c_struct *i2c_imx7ulp) +{ + wait_event_timeout(i2c_imx7ulp->queue, + i2c_imx7ulp->msg_done || (i2c_imx7ulp->msr & MSR_NDF), HZ); + + if (unlikely(i2c_imx7ulp->msr & MSR_NDF)) { + dev_dbg(&i2c_imx7ulp->adapter.dev, + "<%s> NACK Detected\n", __func__); + return -EIO; + } else if (unlikely(!i2c_imx7ulp->msg_done)) { + dev_dbg(&i2c_imx7ulp->adapter.dev, "<%s> Timeout\n", __func__); + return -ETIMEDOUT; + } + + dev_dbg(&i2c_imx7ulp->adapter.dev, "<%s> msg complete\n", __func__); + + i2c_imx7ulp->msr = 0; + return 0; +} + +static void i2c_imx7ulp_read_rxfifo(struct imx7ulp_i2c_struct *i2c_imx7ulp) +{ + unsigned int i, temp; + unsigned int block_len, rcvlen, left; + unsigned int data; + + rcvlen = i2c_imx7ulp->rx_len; + + /* disable receive data interrupt */ + temp = imx7ulp_i2c_read_reg(i2c_imx7ulp, IMX7ULP_I2C_MIER); + temp &= ~MIER_RDIE; + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MIER); + + for (i = 0; i < i2c_imx7ulp->rx_water; i++) { + data = imx7ulp_i2c_read_reg(i2c_imx7ulp, IMX7ULP_I2C_MRDR); + i2c_imx7ulp->rx_buf[i + rcvlen] = data & 0xff; + } + + /* enable receive data interrupt */ + temp = imx7ulp_i2c_read_reg(i2c_imx7ulp, IMX7ULP_I2C_MIER); + temp |= MIER_RDIE; + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MIER); + + i2c_imx7ulp->rx_len += i2c_imx7ulp->rx_water; + + /* + * First byte is the length of remaining packet in the SMBus block + * data read. Add it to msgs->len. + */ + if (i2c_imx7ulp->block_data) { + block_len = i2c_imx7ulp->rx_buf[0]; + if ((block_len == 0) || (block_len > I2C_SMBUS_BLOCK_MAX)) { + wake_up(&i2c_imx7ulp->queue); + return; + } + i2c_imx7ulp->msg_len += block_len; + i2c_imx7ulp->block_data = 0; + } + + if (i2c_imx7ulp->rx_len < i2c_imx7ulp->msg_len) { + left = i2c_imx7ulp->msg_len - i2c_imx7ulp->rx_len; + if (left <= i2c_imx7ulp->rxfifo_size) + i2c_imx7ulp->rx_water = left; + else + i2c_imx7ulp->rx_water = i2c_imx7ulp->rxfifo_size >> 1; + + temp = i2c_imx7ulp->rx_water << 16; + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MFCR); + + /* msg_len > 256, multiple receive commands */ + if (!(i2c_imx7ulp->rx_len && 0xff)) { + /* receive data[7:0]+1 bytes */ + temp = left > CHUNK_DATA ? CHUNK_DATA - 1 : (left - 1); + temp |= (RECV_DATA << 8); + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MTDR); + } + } else { + i2c_imx7ulp->msg_done = 1; + wake_up(&i2c_imx7ulp->queue); + } +} + +static void i2c_imx7ulp_write_txfifo(struct imx7ulp_i2c_struct *i2c_imx7ulp) +{ + unsigned int i; + unsigned int txlen, left, loadnum; + unsigned int data; + + txlen = i2c_imx7ulp->tx_len; + if (txlen < i2c_imx7ulp->msg_len) { + left = i2c_imx7ulp->msg_len - txlen; + if (left <= i2c_imx7ulp->txfifo_size) + loadnum = left; + else + loadnum = i2c_imx7ulp->txfifo_size; + + for (i = 0; i < loadnum; i++) { + data = i2c_imx7ulp->tx_buf[txlen + i]; + imx7ulp_i2c_write_reg(data, i2c_imx7ulp, IMX7ULP_I2C_MTDR); + } + + i2c_imx7ulp->tx_len += loadnum; + } else { + i2c_imx7ulp->msg_done = 1; + wake_up(&i2c_imx7ulp->queue); + } +} + +static irqreturn_t i2c_imx7ulp_isr(int irq, void *dev_id) +{ + unsigned int temp; + struct imx7ulp_i2c_struct *i2c_imx7ulp = dev_id; + + temp = imx7ulp_i2c_read_reg(i2c_imx7ulp, IMX7ULP_I2C_MSR); + i2c_imx7ulp->msr = temp; + + if (temp & MSR_RDF) { + i2c_imx7ulp_read_rxfifo(i2c_imx7ulp); + return IRQ_HANDLED; + } + + if (temp & MSR_TDF) { + i2c_imx7ulp_write_txfifo(i2c_imx7ulp); + return IRQ_HANDLED; + } + + if (temp & MSR_NDF) { + /* write 1 to clear MSR_NDF */ + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MSR); + wake_up(&i2c_imx7ulp->queue); + return IRQ_HANDLED; + } + + return IRQ_NONE; +} + +static int i2c_imx7ulp_write(struct imx7ulp_i2c_struct *i2c_imx7ulp, + struct i2c_msg *msgs) +{ + int result; + unsigned int i, loadnum; + unsigned int data, temp; + + dev_dbg(&i2c_imx7ulp->adapter.dev, "<%s> write slave address: addr=0x%x\n", + __func__, msgs->addr << 1); + + i2c_imx7ulp->msr = 0; + i2c_imx7ulp->tx_len = 0; + i2c_imx7ulp->msg_done = 0; + i2c_imx7ulp->tx_buf = msgs->buf; + i2c_imx7ulp->msg_len = msgs->len; + + temp = imx7ulp_i2c_read_reg(i2c_imx7ulp, IMX7ULP_I2C_MIER); + temp |= MIER_NDIE; + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MIER); + + /* set TXWATER */ + i2c_imx7ulp->tx_water = 0; + temp = i2c_imx7ulp->tx_water; + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MFCR); + + /* generate start and transmit address */ + result = i2c_imx7ulp_tx_addr(i2c_imx7ulp, msgs, 0); + if (result) + goto ret; + + /* load txfifo */ + if (i2c_imx7ulp->msg_len > i2c_imx7ulp->txfifo_size) + loadnum = i2c_imx7ulp->txfifo_size; + else + loadnum = i2c_imx7ulp->msg_len; + + for (i = 0; i < loadnum; i++) { + data = i2c_imx7ulp->tx_buf[i]; + imx7ulp_i2c_write_reg(data, i2c_imx7ulp, IMX7ULP_I2C_MTDR); + } + i2c_imx7ulp->tx_len += loadnum; + + /* transmit data interrupt enable */ + temp = imx7ulp_i2c_read_reg(i2c_imx7ulp, IMX7ULP_I2C_MIER); + temp |= MIER_TDIE; + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MIER); + + result = i2c_imx7ulp_msg_complete(i2c_imx7ulp); +ret: + return result; +} + +static int i2c_imx7ulp_read(struct imx7ulp_i2c_struct *i2c_imx7ulp, + struct i2c_msg *msgs) +{ + int result; + unsigned int temp; + + dev_dbg(&i2c_imx7ulp->adapter.dev, + "<%s> write slave address: addr=0x%x\n", + __func__, (msgs->addr << 1) | 0x01); + + i2c_imx7ulp->msr = 0; + i2c_imx7ulp->rx_len = 0; + i2c_imx7ulp->msg_done = 0; + i2c_imx7ulp->rx_buf = msgs->buf; + i2c_imx7ulp->msg_len = msgs->len; + i2c_imx7ulp->block_data = msgs->flags & I2C_M_RECV_LEN; + + /* receive data interrupt enable */ + temp = imx7ulp_i2c_read_reg(i2c_imx7ulp, IMX7ULP_I2C_MIER); + temp |= MIER_RDIE | MIER_NDIE; + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MIER); + + /* set RXWATER */ + if (i2c_imx7ulp->msg_len > i2c_imx7ulp->rxfifo_size) + i2c_imx7ulp->rx_water = i2c_imx7ulp->rxfifo_size >> 1; + else + i2c_imx7ulp->rx_water = i2c_imx7ulp->msg_len; + temp = i2c_imx7ulp->rx_water << 16; + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MFCR); + + /* generate start and transmit address */ + result = i2c_imx7ulp_tx_addr(i2c_imx7ulp, msgs, 1); + if (result) + goto ret; + + /* receive data[7:0]+1 bytes */ + temp = msgs->len > CHUNK_DATA ? CHUNK_DATA - 1 : msgs->len - 1; + temp |= (RECV_DATA << 8); + imx7ulp_i2c_write_reg(temp, i2c_imx7ulp, IMX7ULP_I2C_MTDR); + + result = i2c_imx7ulp_msg_complete(i2c_imx7ulp); + if (result) + goto ret; + + /* if block length is invalid, the flag can not cleared*/ + if (i2c_imx7ulp->block_data) + result = -EPROTO; + + /* msgs->len is changed when read block data */ + msgs->len = i2c_imx7ulp->msg_len; + +ret: + return result; +} + +static int i2c_imx7ulp_xfer(struct i2c_adapter *adapter, + struct i2c_msg *msgs, int num) +{ + unsigned int i; + int result; + struct imx7ulp_i2c_struct *i2c_imx7ulp = i2c_get_adapdata(adapter); + +#ifdef CONFIG_I2C_DEBUG_BUS + unsigned int temp; +#endif + + dev_dbg(&i2c_imx7ulp->adapter.dev, "<%s>\n", __func__); + + result = i2c_imx7ulp_start(i2c_imx7ulp); + if (result) + return result; + + /* read/write data */ + for (i = 0; i < num; i++) { + dev_dbg(&i2c_imx7ulp->adapter.dev, + "<%s> transfer message: %d\n", __func__, i); + +#ifdef CONFIG_I2C_DEBUG_BUS + temp = imx7ulp_i2c_read_reg(i2c_imx7ulp, IMX7ULP_I2C_MCR); + dev_dbg(&i2c_imx7ulp->adapter.dev, + "<%s> CONTROL: MEN=%d, RST=%d, DOZEN=%d, DBGEN=%d, RTF=%d, RRF=%d\n", + __func__, + (temp & MCR_MEN ? 1 : 0), (temp & MCR_RST ? 1 : 0), + (temp & MCR_DOZEN ? 1 : 0), (temp & MCR_DBGEN ? 1 : 0), + (temp & MCR_RTF ? 1 : 0), (temp & MCR_RRF ? 1 : 0)); +#endif + + if (msgs[i].flags & I2C_M_RD) + result = i2c_imx7ulp_read(i2c_imx7ulp, &msgs[i]); + else + result = i2c_imx7ulp_write(i2c_imx7ulp, &msgs[i]); + if (result) + goto fail0; + } + +fail0: + /* Stop I2C transfer */ + i2c_imx7ulp_stop(i2c_imx7ulp); + + dev_dbg(&i2c_imx7ulp->adapter.dev, "<%s> exit with: %s: %d\n", __func__, + (result < 0) ? "error" : "success msg", + (result < 0) ? result : num); + return (result < 0) ? result : num; +} + +static u32 i2c_imx7ulp_func(struct i2c_adapter *adapter) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL + | I2C_FUNC_SMBUS_READ_BLOCK_DATA; +} + +static struct i2c_algorithm i2c_imx7ulp_algo = { + .master_xfer = i2c_imx7ulp_xfer, + .functionality = i2c_imx7ulp_func, +}; + +static int i2c_imx7ulp_probe(struct platform_device *pdev) +{ + struct imx7ulp_i2c_struct *i2c_imx7ulp; + struct resource *res; + void __iomem *base; + int irq, ret; + unsigned int temp; + + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_err(&pdev->dev, "can't get irq number\n"); + return irq; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(base)) + return PTR_ERR(base); + + i2c_imx7ulp = devm_kzalloc(&pdev->dev, + sizeof(*i2c_imx7ulp), GFP_KERNEL); + if (!i2c_imx7ulp) + return -ENOMEM; + + /* Setup i2c_imx7ulp driver structure */ + strlcpy(i2c_imx7ulp->adapter.name, pdev->name, + sizeof(i2c_imx7ulp->adapter.name)); + i2c_imx7ulp->adapter.owner = THIS_MODULE; + i2c_imx7ulp->adapter.algo = &i2c_imx7ulp_algo; + i2c_imx7ulp->adapter.dev.parent = &pdev->dev; + i2c_imx7ulp->adapter.nr = pdev->id; + i2c_imx7ulp->base = base; + i2c_imx7ulp->adapter.dev.of_node = pdev->dev.of_node; + + /* Get I2C bus clock */ + i2c_imx7ulp->bus_clk = devm_clk_get(&pdev->dev, "bus_clk"); + if (IS_ERR(i2c_imx7ulp->bus_clk)) { + dev_err(&pdev->dev, "can't get I2C bus clock\n"); + return PTR_ERR(i2c_imx7ulp->bus_clk); + } + + /* Get I2C peripheral clock */ + i2c_imx7ulp->per_clk = devm_clk_get(&pdev->dev, "per_clk"); + if (IS_ERR(i2c_imx7ulp->per_clk)) { + dev_err(&pdev->dev, "can't get I2C peripheral clock\n"); + return PTR_ERR(i2c_imx7ulp->per_clk); + } + + ret = clk_prepare_enable(i2c_imx7ulp->bus_clk); + if (ret) { + dev_err(&pdev->dev, + "can't enable I2C bus clock, ret=%d\n", ret); + return ret; + } + + /* Request IRQ */ + ret = devm_request_irq(&pdev->dev, irq, i2c_imx7ulp_isr, 0, + pdev->name, i2c_imx7ulp); + if (ret) { + dev_err(&pdev->dev, "can't claim irq %d\n", irq); + goto clk_disable; + } + + /* Init queue */ + init_waitqueue_head(&i2c_imx7ulp->queue); + + /* Set up adapter data */ + i2c_set_adapdata(&i2c_imx7ulp->adapter, i2c_imx7ulp); + + /* Set up platform driver data */ + platform_set_drvdata(pdev, i2c_imx7ulp); + + /* Read i2c fifosize parameter, unit: words */ + temp = imx7ulp_i2c_read_reg(i2c_imx7ulp, IMX7ULP_I2C_PARAM); + i2c_imx7ulp->txfifo_size = 1 << (temp & 0X000F); + i2c_imx7ulp->rxfifo_size = 1 << (temp & 0X0F00); + + ret = of_property_read_u32(pdev->dev.of_node, + "clock-frequency", &i2c_imx7ulp->bitrate); + if (ret) + i2c_imx7ulp->bitrate = LPI2C_DEFAULT_RATE; + + /*i2c imx7ulp basic config */ + i2c_imx7ulp_set_mode(i2c_imx7ulp); + i2c_imx7ulp_set_bitrate(i2c_imx7ulp); + i2c_imx7ulp_set_pincfg(i2c_imx7ulp); + + /* Add I2C adapter */ + ret = i2c_add_numbered_adapter(&i2c_imx7ulp->adapter); + if (ret) { + dev_err(&pdev->dev, "registration failed\n"); + goto clk_disable; + } + + dev_dbg(&i2c_imx7ulp->adapter.dev, "claimed irq %d\n", irq); + dev_dbg(&i2c_imx7ulp->adapter.dev, "device resources: %pR\n", res); + dev_dbg(&i2c_imx7ulp->adapter.dev, "adapter name: \"%s\"\n", + i2c_imx7ulp->adapter.name); + dev_info(&i2c_imx7ulp->adapter.dev, "IMX I2C adapter registered\n"); + +clk_disable: + clk_disable_unprepare(i2c_imx7ulp->bus_clk); + return ret; +} + +static int i2c_imx7ulp_remove(struct platform_device *pdev) +{ + struct imx7ulp_i2c_struct *i2c_imx7ulp = platform_get_drvdata(pdev); + + i2c_del_adapter(&i2c_imx7ulp->adapter); + clk_disable_unprepare(i2c_imx7ulp->bus_clk); + clk_disable_unprepare(i2c_imx7ulp->per_clk); + + dev_dbg(&i2c_imx7ulp->adapter.dev, "adapter removed\n"); + + return 0; +} + +static struct platform_driver i2c_imx7ulp_driver = { + .probe = i2c_imx7ulp_probe, + .remove = i2c_imx7ulp_remove, + .driver = { + .name = DRIVER_NAME, + }, +}; + +static int __init i2c_adap_imx_init(void) +{ + return platform_driver_register(&i2c_imx7ulp_driver); +} +subsys_initcall(i2c_adap_imx_init); + +static void __exit i2c_adap_imx_exit(void) +{ + platform_driver_unregister(&i2c_imx7ulp_driver); +} +module_exit(i2c_adap_imx_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Gao Pan <pandy.gao@nxp.com>"); +MODULE_DESCRIPTION("I2C adapter driver for IMX7ULP I2C bus"); +MODULE_ALIAS("platform:" DRIVER_NAME);
Add i.MX7ULP i2c bus driver which can continue operating in stop modes provided an appropriate clock is available. It is also designed for low CPU overhead with DMA offloading of FIFO register accesses. Signed-off-by: Gao Pan <pandy.gao@nxp.com> --- drivers/i2c/busses/Kconfig | 10 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-imx7ulp.c | 810 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 821 insertions(+)