diff options
| -rw-r--r-- | drivers/i2c/busses/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/i2c/busses/Makefile | 1 | ||||
| -rw-r--r-- | drivers/i2c/busses/i2c-sh7760.c | 577 | ||||
| -rw-r--r-- | include/asm-sh/i2c-sh7760.h | 22 |
4 files changed, 609 insertions, 0 deletions
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 1577bcad288..d01d0b175e1 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -683,4 +683,13 @@ config I2C_PMCMSP This driver can also be built as module. If so, the module will be called i2c-pmcmsp. +config I2C_SH7760 + tristate "Renesas SH7760 I2C Controller" + depends on CPU_SUBTYPE_SH7760 + help + This driver supports the 2 I2C interfaces on the Renesas SH7760. + + This driver can also be built as a module. If so, the module + will be called i2c-sh7760. + endmenu diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 378d5c07e04..8e72b2649dc 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -38,6 +38,7 @@ obj-$(CONFIG_I2C_PROSAVAGE) += i2c-prosavage.o obj-$(CONFIG_I2C_PXA) += i2c-pxa.o obj-$(CONFIG_I2C_S3C2410) += i2c-s3c2410.o obj-$(CONFIG_I2C_SAVAGE4) += i2c-savage4.o +obj-$(CONFIG_I2C_SH7760) += i2c-sh7760.o obj-$(CONFIG_I2C_SIBYTE) += i2c-sibyte.o obj-$(CONFIG_I2C_SIMTEC) += i2c-simtec.o obj-$(CONFIG_I2C_SIS5595) += i2c-sis5595.o diff --git a/drivers/i2c/busses/i2c-sh7760.c b/drivers/i2c/busses/i2c-sh7760.c new file mode 100644 index 00000000000..5e0e254976d --- /dev/null +++ b/drivers/i2c/busses/i2c-sh7760.c @@ -0,0 +1,577 @@ +/* + * I2C bus driver for the SH7760 I2C Interfaces. + * + * (c) 2005-2008 MSC Vertriebsges.m.b.H, Manuel Lauss <mlau@msc-ge.com> + * + * licensed under the terms outlined in the file COPYING. + * + */ + +#include <linux/completion.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/ioport.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +#include <asm/clock.h> +#include <asm/i2c-sh7760.h> +#include <asm/io.h> + +/* register offsets */ +#define I2CSCR 0x0 /* slave ctrl */ +#define I2CMCR 0x4 /* master ctrl */ +#define I2CSSR 0x8 /* slave status */ +#define I2CMSR 0xC /* master status */ +#define I2CSIER 0x10 /* slave irq enable */ +#define I2CMIER 0x14 /* master irq enable */ +#define I2CCCR 0x18 /* clock dividers */ +#define I2CSAR 0x1c /* slave address */ +#define I2CMAR 0x20 /* master address */ +#define I2CRXTX 0x24 /* data port */ +#define I2CFCR 0x28 /* fifo control */ +#define I2CFSR 0x2C /* fifo status */ +#define I2CFIER 0x30 /* fifo irq enable */ +#define I2CRFDR 0x34 /* rx fifo count */ +#define I2CTFDR 0x38 /* tx fifo count */ + +#define REGSIZE 0x3C + +#define MCR_MDBS 0x80 /* non-fifo mode switch */ +#define MCR_FSCL 0x40 /* override SCL pin */ +#define MCR_FSDA 0x20 /* override SDA pin */ +#define MCR_OBPC 0x10 /* override pins */ +#define MCR_MIE 0x08 /* master if enable */ +#define MCR_TSBE 0x04 +#define MCR_FSB 0x02 /* force stop bit */ +#define MCR_ESG 0x01 /* en startbit gen. */ + +#define MSR_MNR 0x40 /* nack received */ +#define MSR_MAL 0x20 /* arbitration lost */ +#define MSR_MST 0x10 /* sent a stop */ +#define MSR_MDE 0x08 +#define MSR_MDT 0x04 +#define MSR_MDR 0x02 +#define MSR_MAT 0x01 /* slave addr xfer done */ + +#define MIE_MNRE 0x40 /* nack irq en */ +#define MIE_MALE 0x20 /* arblos irq en */ +#define MIE_MSTE 0x10 /* stop irq en */ +#define MIE_MDEE 0x08 +#define MIE_MDTE 0x04 +#define MIE_MDRE 0x02 +#define MIE_MATE 0x01 /* address sent irq en */ + +#define FCR_RFRST 0x02 /* reset rx fifo */ +#define FCR_TFRST 0x01 /* reset tx fifo */ + +#define FSR_TEND 0x04 /* last byte sent */ +#define FSR_RDF 0x02 /* rx fifo trigger */ +#define FSR_TDFE 0x01 /* tx fifo empty */ + +#define FIER_TEIE 0x04 /* tx fifo empty irq en */ +#define FIER_RXIE 0x02 /* rx fifo trig irq en */ +#define FIER_TXIE 0x01 /* tx fifo trig irq en */ + +#define FIFO_SIZE 16 + +struct cami2c { + void __iomem *iobase; + struct i2c_adapter adap; + + /* message processing */ + struct i2c_msg *msg; +#define IDF_SEND 1 +#define IDF_RECV 2 +#define IDF_STOP 4 + int flags; + +#define IDS_DONE 1 +#define IDS_ARBLOST 2 +#define IDS_NACK 4 + int status; + struct completion xfer_done; + + int irq; + struct resource *ioarea; +}; + +static inline void OUT32(struct cami2c *cam, int reg, unsigned long val) +{ + ctrl_outl(val, (unsigned long)cam->iobase + reg); +} + +static inline unsigned long IN32(struct cami2c *cam, int reg) +{ + return ctrl_inl((unsigned long)cam->iobase + reg); +} + +static irqreturn_t sh7760_i2c_irq(int irq, void *ptr) +{ + struct cami2c *id = ptr; + struct i2c_msg *msg = id->msg; + char *data = msg->buf; + unsigned long msr, fsr, fier, len; + + msr = IN32(id, I2CMSR); + fsr = IN32(id, I2CFSR); + + /* arbitration lost */ + if (msr & MSR_MAL) { + OUT32(id, I2CMCR, 0); + OUT32(id, I2CSCR, 0); + OUT32(id, I2CSAR, 0); + id->status |= IDS_DONE | IDS_ARBLOST; + goto out; + } + + if (msr & MSR_MNR) { + /* NACK handling is very screwed up. After receiving a + * NAK IRQ one has to wait a bit before writing to any + * registers, or the ctl will lock up. After that delay + * do a normal i2c stop. Then wait at least 1 ms before + * attempting another transfer or ctl will stop working + */ + udelay(100); /* wait or risk ctl hang */ + OUT32(id, I2CFCR, FCR_RFRST | FCR_TFRST); + OUT32(id, I2CMCR, MCR_MIE | MCR_FSB); + OUT32(id, I2CFIER, 0); + OUT32(id, I2CMIER, MIE_MSTE); + OUT32(id, I2CSCR, 0); + OUT32(id, I2CSAR, 0); + id->status |= IDS_NACK; + msr &= ~MSR_MAT; + fsr = 0; + /* In some cases the MST bit is also set. */ + } + + /* i2c-stop was sent */ + if (msr & MSR_MST) { + id->status |= IDS_DONE; + goto out; + } + + /* i2c slave addr was sent; set to "normal" operation */ + if (msr & MSR_MAT) + OUT32(id, I2CMCR, MCR_MIE); + + fier = IN32(id, I2CFIER); + + if (fsr & FSR_RDF) { + len = IN32(id, I2CRFDR); + if (msg->len <= len) { + if (id->flags & IDF_STOP) { + OUT32(id, I2CMCR, MCR_MIE | MCR_FSB); + OUT32(id, I2CFIER, 0); + /* manual says: wait >= 0.5 SCL times */ + udelay(5); + /* next int should be MST */ + } else { + id->status |= IDS_DONE; + /* keep the RDF bit: ctrl holds SCL low + * until the setup for the next i2c_msg + * clears this bit. + */ + fsr &= ~FSR_RDF; + } + } + while (msg->len && len) { + *data++ = IN32(id, I2CRXTX); + msg->len--; + len--; + } + + if (msg->len) { + len = (msg->len >= FIFO_SIZE) ? FIFO_SIZE - 1 + : msg->len - 1; + + OUT32(id, I2CFCR, FCR_TFRST | ((len & 0xf) << 4)); + } + + } else if (id->flags & IDF_SEND) { + if ((fsr & FSR_TEND) && (msg->len < 1)) { + if (id->flags & IDF_STOP) { + OUT32(id, I2CMCR, MCR_MIE | MCR_FSB); + } else { + id->status |= IDS_DONE; + /* keep the TEND bit: ctl holds SCL low + * until the setup for the next i2c_msg + * clears this bit. + */ + fsr &= ~FSR_TEND; + } + } + if (fsr & FSR_TDFE) { + while (msg->len && (IN32(id, I2CTFDR) < FIFO_SIZE)) { + OUT32(id, I2CRXTX, *data++); + msg->len--; + } + + if (msg->len < 1) { + fier &= ~FIER_TXIE; + OUT32(id, I2CFIER, fier); + } else { + len = (msg->len >= FIFO_SIZE) ? 2 : 0; + OUT32(id, I2CFCR, + FCR_RFRST | ((len & 3) << 2)); + } + } + } +out: + if (id->status & IDS_DONE) { + OUT32(id, I2CMIER, 0); + OUT32(id, I2CFIER, 0); + id->msg = NULL; + complete(&id->xfer_done); + } + /* clear status flags and ctrl resumes work */ + OUT32(id, I2CMSR, ~msr); + OUT32(id, I2CFSR, ~fsr); + OUT32(id, I2CSSR, 0); + + return IRQ_HANDLED; +} + + +/* prepare and start a master receive operation */ +static void sh7760_i2c_mrecv(struct cami2c *id) +{ + int len; + + id->flags |= IDF_RECV; + + /* set the slave addr reg; otherwise rcv wont work! */ + OUT32(id, I2CSAR, 0xfe); + OUT32(id, I2CMAR, (id->msg->addr << 1) | 1); + + /* adjust rx fifo trigger */ + if (id->msg->len >= FIFO_SIZE) + len = FIFO_SIZE - 1; /* trigger at fifo full */ + else + len = id->msg->len - 1; /* trigger before all received */ + + OUT32(id, I2CFCR, FCR_RFRST | FCR_TFRST); + OUT32(id, I2CFCR, FCR_TFRST | ((len & 0xF) << 4)); + + OUT32(id, I2CMSR, 0); + OUT32(id, I2CMCR, MCR_MIE | MCR_ESG); + OUT32(id, I2CMIER, MIE_MNRE | MIE_MALE | MIE_MSTE | MIE_MATE); + OUT32(id, I2CFIER, FIER_RXIE); +} + +/* prepare and start a master send operation */ +static void sh7760_i2c_msend(struct cami2c *id) +{ + int len; + + id->flags |= IDF_SEND; + + /* set the slave addr reg; otherwise xmit wont work! */ + OUT32(id, I2CSAR, 0xfe); + OUT32(id, I2CMAR, (id->msg->addr << 1) | 0); + + /* adjust tx fifo trigger */ + if (id->msg->len >= FIFO_SIZE) + len = 2; /* trig: 2 bytes left in TX fifo */ + else + len = 0; /* trig: 8 bytes left in TX fifo */ + + OUT32(id, I2CFCR, FCR_RFRST | FCR_TFRST); + OUT32(id, I2CFCR, FCR_RFRST | ((len & 3) << 2)); + + while (id->msg->len && IN32(id, I2CTFDR) < FIFO_SIZE) { + OUT32(id, I2CRXTX, *(id->msg->buf)); + (id->msg->len)--; + (id->msg->buf)++; + } + + OUT32(id, I2CMSR, 0); + OUT32(id, I2CMCR, MCR_MIE | MCR_ESG); + OUT32(id, I2CFSR, 0); + OUT32(id, I2CMIER, MIE_MNRE | MIE_MALE | MIE_MSTE | MIE_MATE); + OUT32(id, I2CFIER, FIER_TEIE | (id->msg->len ? FIER_TXIE : 0)); +} + +static inline int sh7760_i2c_busy_check(struct cami2c *id) +{ + return (IN32(id, I2CMCR) & MCR_FSDA); +} + +static int sh7760_i2c_master_xfer(struct i2c_adapter *adap, + struct i2c_msg *msgs, + int num) +{ + struct cami2c *id = adap->algo_data; + int i, retr; + + if (sh7760_i2c_busy_check(id)) { + dev_err(&adap->dev, "sh7760-i2c%d: bus busy!\n", adap->nr); + return -EBUSY; + } + + i = 0; + while (i < num) { + retr = adap->retries; +retry: + id->flags = ((i == (num-1)) ? IDF_STOP : 0); + id->status = 0; + id->msg = msgs; + init_completion(&id->xfer_done); + + if (msgs->flags & I2C_M_RD) + sh7760_i2c_mrecv(id); + else + sh7760_i2c_msend(id); + + wait_for_completion(&id->xfer_done); + + if (id->status == 0) { + num = -EIO; + break; + } + + if (id->status & IDS_NACK) { + /* wait a bit or i2c module stops working */ + mdelay(1); + num = -EREMOTEIO; + break; + } + + if (id->status & IDS_ARBLOST) { + if (retr--) { + mdelay(2); + goto retry; + } + num = -EREMOTEIO; + break; + } + + msgs++; + i++; + } + + id->msg = NULL; + id->flags = 0; + id->status = 0; + + OUT32(id, I2CMCR, 0); + OUT32(id, I2CMSR, 0); + OUT32(id, I2CMIER, 0); + OUT32(id, I2CFIER, 0); + + /* reset slave module registers too: master mode enables slave + * module for receive ops (ack, data). Without this reset, + * eternal bus activity might be reported after NACK / ARBLOST. + */ + OUT32(id, I2CSCR, 0); + OUT32(id, I2CSAR, 0); + OUT32(id, I2CSSR, 0); + + return num; +} + +static u32 sh7760_i2c_func(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK); +} + +static const struct i2c_algorithm sh7760_i2c_algo = { + .master_xfer = sh7760_i2c_master_xfer, + .functionality = sh7760_i2c_func, +}; + +/* calculate CCR register setting for a desired scl clock. SCL clock is + * derived from I2C module clock (iclk) which in turn is derived from + * peripheral module clock (mclk, usually around 33MHz): + * iclk = mclk/(CDF + 1). iclk must be < 20MHz. + * scl = iclk/(SCGD*8 + 20). + */ +static int __devinit calc_CCR(unsigned long scl_hz) +{ + struct clk *mclk; + unsigned long mck, m1, dff, odff, iclk; + signed char cdf, cdfm; + int scgd, scgdm, scgds; + + mclk = clk_get(NULL, "module_clk"); + if (IS_ERR(mclk)) { + return PTR_ERR(mclk); + } else { + mck = mclk->rate; + clk_put(mclk); + } + + odff = scl_hz; + scgdm = cdfm = m1 = 0; + for (cdf = 3; cdf >= 0; cdf--) { + iclk = mck / (1 + cdf); + if (iclk >= 20000000) + continue; + scgds = ((iclk / scl_hz) - 20) >> 3; + for (scgd = scgds; (scgd < 63) && scgd <= scgds + 1; scgd++) { + m1 = iclk / (20 + (scgd << 3)); + dff = abs(scl_hz - m1); + if (dff < odff) { + odff = dff; + cdfm = cdf; + scgdm = scgd; + } + } + } + /* fail if more than 25% off of requested SCL */ + if (odff > (scl_hz >> 2)) + return -EINVAL; + + /* create a CCR register value */ + return ((scgdm << 2) | cdfm); +} + +static int __devinit sh7760_i2c_probe(struct platform_device *pdev) +{ + struct sh7760_i2c_platdata *pd; + struct resource *res; + struct cami2c *id; + int ret; + + pd = pdev->dev.platform_data; + if (!pd) { + dev_err(&pdev->dev, "no platform_data!\n"); + ret = -ENODEV; + goto out0; + } + + id = kzalloc(sizeof(struct cami2c), GFP_KERNEL); + if (!id) { + dev_err(&pdev->dev, "no mem for private data\n"); + ret = -ENOMEM; + goto out0; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + dev_err(&pdev->dev, "no mmio resources\n"); + ret = -ENODEV; + goto out1; + } + + id->ioarea = request_mem_region(res->start, REGSIZE, pdev->name); + if (!id->ioarea) { + dev_err(&pdev->dev, "mmio already reserved\n"); + ret = -EBUSY; + goto out1; + } + + id->iobase = ioremap(res->start, REGSIZE); + if (!id->iobase) { + dev_err(&pdev->dev, "cannot ioremap\n"); + ret = -ENODEV; + goto out2; + } + + id->irq = platform_get_irq(pdev, 0); + + id->adap.nr = pdev->id; + id->adap.algo = &sh7760_i2c_algo; + id->adap.class = I2C_CLASS_ALL; + id->adap.retries = 3; + id->adap.algo_data = id; + id->adap.dev.parent = &pdev->dev; + snprintf(id->adap.name, sizeof(id->adap.name), + "SH7760 I2C at %08lx", (unsigned long)res->start); + + OUT32(id, I2CMCR, 0); + OUT32(id, I2CMSR, 0); + OUT32(id, I2CMIER, 0); + OUT32(id, I2CMAR, 0); + OUT32(id, I2CSIER, 0); + OUT32(id, I2CSAR, 0); + OUT32(id, I2CSCR, 0); + OUT32(id, I2CSSR, 0); + OUT32(id, I2CFIER, 0); + OUT32(id, I2CFCR, FCR_RFRST | FCR_TFRST); + OUT32(id, I2CFSR, 0); + + ret = calc_CCR(pd->speed_khz * 1000); + if (ret < 0) { + dev_err(&pdev->dev, "invalid SCL clock: %dkHz\n", + pd->speed_khz); + goto out3; + } + OUT32(id, I2CCCR, ret); + + if (request_irq(id->irq, sh7760_i2c_irq, IRQF_DISABLED, + SH7760_I2C_DEVNAME, id)) { + dev_err(&pdev->dev, "cannot get irq %d\n", id->irq); + ret = -EBUSY; + goto out3; + } + + ret = i2c_add_numbered_adapter(&id->adap); + if (ret < 0) { + dev_err(&pdev->dev, "reg adap failed: %d\n", ret); + goto out4; + } + + platform_set_drvdata(pdev, id); + + dev_info(&pdev->dev, "%d kHz mmio %08x irq %d\n", + pd->speed_khz, res->start, id->irq); + + return 0; + +out4: + free_irq(id->irq, id); +out3: + iounmap(id->iobase); +out2: + release_resource(id->ioarea); + kfree(id->ioarea); +out1: + kfree(id); +out0: + return ret; +} + +static int __devexit sh7760_i2c_remove(struct platform_device *pdev) +{ + struct cami2c *id = platform_get_drvdata(pdev); + + i2c_del_adapter(&id->adap); + free_irq(id->irq, id); + iounmap(id->iobase); + release_resource(id->ioarea); + kfree(id->ioarea); + kfree(id); + platform_set_drvdata(pdev, NULL); + + return 0; +} + +static struct platform_driver sh7760_i2c_drv = { + .driver = { + .name = SH7760_I2C_DEVNAME, + .owner = THIS_MODULE, + }, + .probe = sh7760_i2c_probe, + .remove = __devexit_p(sh7760_i2c_remove), +}; + +static int __init sh7760_i2c_init(void) +{ + return platform_driver_register(&sh7760_i2c_drv); +} + +static void __exit sh7760_i2c_exit(void) +{ + platform_driver_unregister(&sh7760_i2c_drv); +} + +module_init(sh7760_i2c_init); +module_exit(sh7760_i2c_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("SH7760 I2C bus driver"); +MODULE_AUTHOR("Manuel Lauss <mano@roarinelk.homelinux.net>"); diff --git a/include/asm-sh/i2c-sh7760.h b/include/asm-sh/i2c-sh7760.h new file mode 100644 index 00000000000..24182116711 --- /dev/null +++ b/include/asm-sh/i2c-sh7760.h @@ -0,0 +1,22 @@ +/* + * MMIO/IRQ and platform data for SH7760 I2C channels + */ + +#ifndef _I2C_SH7760_H_ +#define _I2C_SH7760_H_ + +#define SH7760_I2C_DEVNAME "sh7760-i2c" + +#define SH7760_I2C0_MMIO 0xFE140000 +#define SH7760_I2C0_MMIOEND 0xFE14003B +#define SH7760_I2C0_IRQ 62 + +#define SH7760_I2C1_MMIO 0xFE150000 +#define SH7760_I2C1_MMIOEND 0xFE15003B +#define SH7760_I2C1_IRQ 63 + +struct sh7760_i2c_platdata { + unsigned int speed_khz; +}; + +#endif |