From 12a55f2db71e0a1474ba56ab1c93287600b915be Mon Sep 17 00:00:00 2001 From: Magnus Damm Date: Thu, 11 Mar 2010 10:05:50 +0000 Subject: i2c: i2c-sh_mobile register access code break out Break out register access functions in the i2c-sh_mobile driver. This update should not change any driver logic. Signed-off-by: Magnus Damm Signed-off-by: Paul Mundt --- drivers/i2c/busses/i2c-sh_mobile.c | 90 ++++++++++++++++++++++---------------- 1 file changed, 53 insertions(+), 37 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c index ffb405d7c6f2..d2fabd9dbf80 100644 --- a/drivers/i2c/busses/i2c-sh_mobile.c +++ b/drivers/i2c/busses/i2c-sh_mobile.c @@ -132,12 +132,12 @@ struct sh_mobile_i2c_data { #define NORMAL_SPEED 100000 /* FAST_SPEED 400000 */ /* Register offsets */ -#define ICDR(pd) (pd->reg + 0x00) -#define ICCR(pd) (pd->reg + 0x04) -#define ICSR(pd) (pd->reg + 0x08) -#define ICIC(pd) (pd->reg + 0x0c) -#define ICCL(pd) (pd->reg + 0x10) -#define ICCH(pd) (pd->reg + 0x14) +#define ICDR 0x00 +#define ICCR 0x04 +#define ICSR 0x08 +#define ICIC 0x0c +#define ICCL 0x10 +#define ICCH 0x14 /* Register bits */ #define ICCR_ICE 0x80 @@ -160,6 +160,22 @@ struct sh_mobile_i2c_data { #define ICIC_WAITE 0x02 #define ICIC_DTEE 0x01 +static void iic_wr(struct sh_mobile_i2c_data *pd, int offs, unsigned char data) +{ + iowrite8(data, pd->reg + offs); +} + +static unsigned char iic_rd(struct sh_mobile_i2c_data *pd, int offs) +{ + return ioread8(pd->reg + offs); +} + +static void iic_set_clr(struct sh_mobile_i2c_data *pd, int offs, + unsigned char set, unsigned char clr) +{ + iic_wr(pd, offs, (iic_rd(pd, offs) | set) & ~clr); +} + static void activate_ch(struct sh_mobile_i2c_data *pd) { unsigned long i2c_clk; @@ -197,24 +213,24 @@ static void activate_ch(struct sh_mobile_i2c_data *pd) pd->icch = (u_int8_t)(num/denom); /* Enable channel and configure rx ack */ - iowrite8(ioread8(ICCR(pd)) | ICCR_ICE, ICCR(pd)); + iic_set_clr(pd, ICCR, ICCR_ICE, 0); /* Mask all interrupts */ - iowrite8(0, ICIC(pd)); + iic_wr(pd, ICIC, 0); /* Set the clock */ - iowrite8(pd->iccl, ICCL(pd)); - iowrite8(pd->icch, ICCH(pd)); + iic_wr(pd, ICCL, pd->iccl); + iic_wr(pd, ICCH, pd->icch); } static void deactivate_ch(struct sh_mobile_i2c_data *pd) { /* Clear/disable interrupts */ - iowrite8(0, ICSR(pd)); - iowrite8(0, ICIC(pd)); + iic_wr(pd, ICSR, 0); + iic_wr(pd, ICIC, 0); /* Disable channel */ - iowrite8(ioread8(ICCR(pd)) & ~ICCR_ICE, ICCR(pd)); + iic_set_clr(pd, ICCR, 0, ICCR_ICE); /* Disable clock and mark device as idle */ clk_disable(pd->clk); @@ -233,35 +249,35 @@ static unsigned char i2c_op(struct sh_mobile_i2c_data *pd, switch (op) { case OP_START: /* issue start and trigger DTE interrupt */ - iowrite8(0x94, ICCR(pd)); + iic_wr(pd, ICCR, 0x94); break; case OP_TX_FIRST: /* disable DTE interrupt and write data */ - iowrite8(ICIC_WAITE | ICIC_ALE | ICIC_TACKE, ICIC(pd)); - iowrite8(data, ICDR(pd)); + iic_wr(pd, ICIC, ICIC_WAITE | ICIC_ALE | ICIC_TACKE); + iic_wr(pd, ICDR, data); break; case OP_TX: /* write data */ - iowrite8(data, ICDR(pd)); + iic_wr(pd, ICDR, data); break; case OP_TX_STOP: /* write data and issue a stop afterwards */ - iowrite8(data, ICDR(pd)); - iowrite8(0x90, ICCR(pd)); + iic_wr(pd, ICDR, data); + iic_wr(pd, ICCR, 0x90); break; case OP_TX_TO_RX: /* select read mode */ - iowrite8(0x81, ICCR(pd)); + iic_wr(pd, ICCR, 0x81); break; case OP_RX: /* just read data */ - ret = ioread8(ICDR(pd)); + ret = iic_rd(pd, ICDR); break; case OP_RX_STOP: /* enable DTE interrupt, issue stop */ - iowrite8(ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE, - ICIC(pd)); - iowrite8(0xc0, ICCR(pd)); + iic_wr(pd, ICIC, + ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE); + iic_wr(pd, ICCR, 0xc0); break; case OP_RX_STOP_DATA: /* enable DTE interrupt, read data, issue stop */ - iowrite8(ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE, - ICIC(pd)); - ret = ioread8(ICDR(pd)); - iowrite8(0xc0, ICCR(pd)); + iic_wr(pd, ICIC, + ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE); + ret = iic_rd(pd, ICDR); + iic_wr(pd, ICCR, 0xc0); break; } @@ -367,7 +383,7 @@ static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id) unsigned char sr; int wakeup; - sr = ioread8(ICSR(pd)); + sr = iic_rd(pd, ICSR); pd->sr |= sr; /* remember state */ dev_dbg(pd->dev, "i2c_isr 0x%02x 0x%02x %s %d %d!\n", sr, pd->sr, @@ -376,7 +392,7 @@ static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id) if (sr & (ICSR_AL | ICSR_TACK)) { /* don't interrupt transaction - continue to issue stop */ - iowrite8(sr & ~(ICSR_AL | ICSR_TACK), ICSR(pd)); + iic_wr(pd, ICSR, sr & ~(ICSR_AL | ICSR_TACK)); wakeup = 0; } else if (pd->msg->flags & I2C_M_RD) wakeup = sh_mobile_i2c_isr_rx(pd); @@ -384,7 +400,7 @@ static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id) wakeup = sh_mobile_i2c_isr_tx(pd); if (sr & ICSR_WAIT) /* TODO: add delay here to support slow acks */ - iowrite8(sr & ~ICSR_WAIT, ICSR(pd)); + iic_wr(pd, ICSR, sr & ~ICSR_WAIT); if (wakeup) { pd->sr |= SW_DONE; @@ -402,21 +418,21 @@ static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg) } /* Initialize channel registers */ - iowrite8(ioread8(ICCR(pd)) & ~ICCR_ICE, ICCR(pd)); + iic_set_clr(pd, ICCR, 0, ICCR_ICE); /* Enable channel and configure rx ack */ - iowrite8(ioread8(ICCR(pd)) | ICCR_ICE, ICCR(pd)); + iic_set_clr(pd, ICCR, ICCR_ICE, 0); /* Set the clock */ - iowrite8(pd->iccl, ICCL(pd)); - iowrite8(pd->icch, ICCH(pd)); + iic_wr(pd, ICCL, pd->iccl); + iic_wr(pd, ICCH, pd->icch); pd->msg = usr_msg; pd->pos = -1; pd->sr = 0; /* Enable all interrupts to begin with */ - iowrite8(ICIC_WAITE | ICIC_ALE | ICIC_TACKE | ICIC_DTEE, ICIC(pd)); + iic_wr(pd, ICIC, ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE); return 0; } @@ -451,7 +467,7 @@ static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter, retry_count = 1000; again: - val = ioread8(ICSR(pd)); + val = iic_rd(pd, ICSR); dev_dbg(pd->dev, "val 0x%02x pd->sr 0x%02x\n", val, pd->sr); -- cgit v1.2.2 From 962b6032c889ed9a5f0bdb7052d9318067a75bda Mon Sep 17 00:00:00 2001 From: Magnus Damm Date: Thu, 11 Mar 2010 10:06:02 +0000 Subject: i2c: i2c-sh_mobile support for new ICIC bits Add support for a new version of the IIC block found in the SH-Mobile ARM line of processors. Prototype patch written by Nishimoto-san. Tested on sh7377 and sh7372. Signed-off-by: NISHIMOTO Hiroki Signed-off-by: Magnus Damm Signed-off-by: Paul Mundt --- drivers/i2c/busses/i2c-sh_mobile.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c index d2fabd9dbf80..598c49acaeb5 100644 --- a/drivers/i2c/busses/i2c-sh_mobile.c +++ b/drivers/i2c/busses/i2c-sh_mobile.c @@ -119,8 +119,10 @@ struct sh_mobile_i2c_data { struct i2c_adapter adap; struct clk *clk; + u_int8_t icic; u_int8_t iccl; u_int8_t icch; + u_int8_t flags; spinlock_t lock; wait_queue_head_t wait; @@ -129,6 +131,8 @@ struct sh_mobile_i2c_data { int sr; }; +#define IIC_FLAG_HAS_ICIC67 (1 << 0) + #define NORMAL_SPEED 100000 /* FAST_SPEED 400000 */ /* Register offsets */ @@ -155,6 +159,8 @@ struct sh_mobile_i2c_data { #define ICSR_WAIT 0x02 #define ICSR_DTE 0x01 +#define ICIC_ICCLB8 0x80 +#define ICIC_ICCHB8 0x40 #define ICIC_ALE 0x08 #define ICIC_TACKE 0x04 #define ICIC_WAITE 0x02 @@ -162,6 +168,9 @@ struct sh_mobile_i2c_data { static void iic_wr(struct sh_mobile_i2c_data *pd, int offs, unsigned char data) { + if (offs == ICIC) + data |= pd->icic; + iowrite8(data, pd->reg + offs); } @@ -203,6 +212,14 @@ static void activate_ch(struct sh_mobile_i2c_data *pd) else pd->iccl = (u_int8_t)(num/denom); + /* one more bit of ICCL in ICIC */ + if (pd->flags & IIC_FLAG_HAS_ICIC67) { + if ((num/denom) > 0xff) + pd->icic |= ICIC_ICCLB8; + else + pd->icic &= ~ICIC_ICCLB8; + } + /* Calculate the value for icch. From the data sheet: icch = (p clock / transfer rate) * (H / (L + H)) */ num = i2c_clk * 4; @@ -212,6 +229,14 @@ static void activate_ch(struct sh_mobile_i2c_data *pd) else pd->icch = (u_int8_t)(num/denom); + /* one more bit of ICCH in ICIC */ + if (pd->flags & IIC_FLAG_HAS_ICIC67) { + if ((num/denom) > 0xff) + pd->icic |= ICIC_ICCHB8; + else + pd->icic &= ~ICIC_ICCHB8; + } + /* Enable channel and configure rx ack */ iic_set_clr(pd, ICCR, ICCR_ICE, 0); @@ -592,6 +617,12 @@ static int sh_mobile_i2c_probe(struct platform_device *dev) goto err_irq; } + /* The IIC blocks on SH-Mobile ARM processors + * come with two new bits in ICIC. + */ + if (size > 0x17) + pd->flags |= IIC_FLAG_HAS_ICIC67; + /* Enable Runtime PM for this device. * * Also tell the Runtime PM core to ignore children -- cgit v1.2.2 From 0924fada1e64f92dd89818cf3a15571cc515afd8 Mon Sep 17 00:00:00 2001 From: Magnus Damm Date: Thu, 11 Mar 2010 10:06:15 +0000 Subject: i2c: i2c-sh_mobile kconfig update for SH-Mobile ARM Update the Kconfig entry for the i2c-sh_mobile driver to enable build on SH-Mobile ARM platforms Signed-off-by: Kuninori Morimoto Signed-off-by: Magnus Damm Signed-off-by: Paul Mundt --- drivers/i2c/busses/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 9c6170cd9aac..41b0754eaf62 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -529,7 +529,7 @@ config I2C_SH7760 config I2C_SH_MOBILE tristate "SuperH Mobile I2C Controller" - depends on SUPERH + depends on SUPERH || ARCH_SHMOBILE help If you say yes to this option, support will be included for the built-in I2C interface on the Renesas SH-Mobile processor. -- cgit v1.2.2 From 4b623926ba8e29393077fc3e01d1141a3ee2e2e9 Mon Sep 17 00:00:00 2001 From: Naveen Krishna Ch Date: Thu, 29 Jul 2010 18:49:34 +0900 Subject: ARM: SAMSUNG: i2c/busses: Add HAVE_S3C2410_I2C option to include I2C for Samsung SoCs This patch adds HAVE_S3C2410_I2C to control inclusion of I2C bus driver on Samsung SoCs and makes I2C bus driver dependency SoC specific instead of machine specific. This will enalbe all machines using Samsung ARCH_S3C2410, _S3C64XX, _S5P6440, _S5PC100, and _S5PV210 to select the I2C driver by default Signed-off-by: Naveen Krishna Ch Signed-off-by: Kukjin Kim Cc: Ben Dooks --- drivers/i2c/busses/Kconfig | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index bceafbfa7268..80143899ccec 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -521,12 +521,19 @@ config I2C_PXA_SLAVE is necessary for systems where the PXA may be a target on the I2C bus. +config HAVE_S3C2410_I2C + bool + help + This will include I2C support for Samsung SoCs. If you want to + include I2C support for any machine, kindly select this in the + respective Kconfig file. + config I2C_S3C2410 tristate "S3C2410 I2C Driver" - depends on ARCH_S3C2410 || ARCH_S3C64XX + depends on HAVE_S3C2410_I2C help Say Y here to include support for I2C controller in the - Samsung S3C2410 based System-on-Chip devices. + Samsung SoCs. config I2C_S6000 tristate "S6000 I2C support" -- cgit v1.2.2 From 2dc11581376829303b98eadb2de253bee065a56a Mon Sep 17 00:00:00 2001 From: Grant Likely Date: Fri, 6 Aug 2010 09:25:50 -0600 Subject: of/device: Replace struct of_device with struct platform_device of_device is just an alias for platform_device, so remove it entirely. Also replace to_of_device() with to_platform_device() and update comment blocks. This patch was initially generated from the following semantic patch, and then edited by hand to pick up the bits that coccinelle didn't catch. @@ @@ -struct of_device +struct platform_device Signed-off-by: Grant Likely Reviewed-by: David S. Miller --- drivers/i2c/busses/i2c-cpm.c | 8 ++++---- drivers/i2c/busses/i2c-ibm_iic.c | 6 +++--- drivers/i2c/busses/i2c-mpc.c | 4 ++-- 3 files changed, 9 insertions(+), 9 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-cpm.c b/drivers/i2c/busses/i2c-cpm.c index e591de1bc704..f7bd2613cecc 100644 --- a/drivers/i2c/busses/i2c-cpm.c +++ b/drivers/i2c/busses/i2c-cpm.c @@ -105,7 +105,7 @@ struct i2c_reg { struct cpm_i2c { char *base; - struct of_device *ofdev; + struct platform_device *ofdev; struct i2c_adapter adap; uint dp_addr; int version; /* CPM1=1, CPM2=2 */ @@ -428,7 +428,7 @@ static const struct i2c_adapter cpm_ops = { static int __devinit cpm_i2c_setup(struct cpm_i2c *cpm) { - struct of_device *ofdev = cpm->ofdev; + struct platform_device *ofdev = cpm->ofdev; const u32 *data; int len, ret, i; void __iomem *i2c_base; @@ -634,7 +634,7 @@ static void cpm_i2c_shutdown(struct cpm_i2c *cpm) cpm_muram_free(cpm->i2c_addr); } -static int __devinit cpm_i2c_probe(struct of_device *ofdev, +static int __devinit cpm_i2c_probe(struct platform_device *ofdev, const struct of_device_id *match) { int result, len; @@ -687,7 +687,7 @@ out_free: return result; } -static int __devexit cpm_i2c_remove(struct of_device *ofdev) +static int __devexit cpm_i2c_remove(struct platform_device *ofdev) { struct cpm_i2c *cpm = dev_get_drvdata(&ofdev->dev); diff --git a/drivers/i2c/busses/i2c-ibm_iic.c b/drivers/i2c/busses/i2c-ibm_iic.c index 1168d61418c9..43ca32fddde2 100644 --- a/drivers/i2c/busses/i2c-ibm_iic.c +++ b/drivers/i2c/busses/i2c-ibm_iic.c @@ -661,7 +661,7 @@ static inline u8 iic_clckdiv(unsigned int opb) return (u8)((opb + 9) / 10 - 1); } -static int __devinit iic_request_irq(struct of_device *ofdev, +static int __devinit iic_request_irq(struct platform_device *ofdev, struct ibm_iic_private *dev) { struct device_node *np = ofdev->dev.of_node; @@ -692,7 +692,7 @@ static int __devinit iic_request_irq(struct of_device *ofdev, /* * Register single IIC interface */ -static int __devinit iic_probe(struct of_device *ofdev, +static int __devinit iic_probe(struct platform_device *ofdev, const struct of_device_id *match) { struct device_node *np = ofdev->dev.of_node; @@ -780,7 +780,7 @@ error_cleanup: /* * Cleanup initialized IIC interface */ -static int __devexit iic_remove(struct of_device *ofdev) +static int __devexit iic_remove(struct platform_device *ofdev) { struct ibm_iic_private *dev = dev_get_drvdata(&ofdev->dev); diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c index 6545d1c99b61..a1c419a716af 100644 --- a/drivers/i2c/busses/i2c-mpc.c +++ b/drivers/i2c/busses/i2c-mpc.c @@ -560,7 +560,7 @@ static struct i2c_adapter mpc_ops = { .timeout = HZ, }; -static int __devinit fsl_i2c_probe(struct of_device *op, +static int __devinit fsl_i2c_probe(struct platform_device *op, const struct of_device_id *match) { struct mpc_i2c *i2c; @@ -646,7 +646,7 @@ static int __devinit fsl_i2c_probe(struct of_device *op, return result; }; -static int __devexit fsl_i2c_remove(struct of_device *op) +static int __devexit fsl_i2c_remove(struct platform_device *op) { struct mpc_i2c *i2c = dev_get_drvdata(&op->dev); -- cgit v1.2.2 From 35a56c5b821c1a5ab904018f322a8e45afd116f0 Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Wed, 11 Aug 2010 18:20:54 +0200 Subject: i2c-dev: Remove unnecessary kmalloc casts Signed-off-by: Joe Perches Signed-off-by: Jean Delvare --- drivers/i2c/i2c-dev.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c index e0694e4d86c7..b3fcb59a5a10 100644 --- a/drivers/i2c/i2c-dev.c +++ b/drivers/i2c/i2c-dev.c @@ -219,9 +219,7 @@ static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client, if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS) return -EINVAL; - rdwr_pa = (struct i2c_msg *) - kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg), - GFP_KERNEL); + rdwr_pa = kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg), GFP_KERNEL); if (!rdwr_pa) return -ENOMEM; -- cgit v1.2.2 From f1c2e33c295de423db5740647bfaa5e2ad139192 Mon Sep 17 00:00:00 2001 From: Julia Lawall Date: Wed, 11 Aug 2010 18:20:55 +0200 Subject: i2c-dev: Use memdup_user Use memdup_user when user data is immediately copied into the allocated region. Note that in the second case, the ++i is no longer necessary, as the last value is already freed if needed by the call to memdup_user. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // @@ expression from,to,size,flag; position p; identifier l1,l2; @@ - to = \(kmalloc@p\|kzalloc@p\)(size,flag); + to = memdup_user(from,size); if ( - to==NULL + IS_ERR(to) || ...) { <+... when != goto l1; - -ENOMEM + PTR_ERR(to) ...+> } - if (copy_from_user(to, from, size) != 0) { - <+... when != goto l2; - -EFAULT - ...+> - } // Signed-off-by: Julia Lawall Signed-off-by: Jean Delvare --- drivers/i2c/i2c-dev.c | 22 ++++++---------------- 1 file changed, 6 insertions(+), 16 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c index b3fcb59a5a10..0b0427f7d348 100644 --- a/drivers/i2c/i2c-dev.c +++ b/drivers/i2c/i2c-dev.c @@ -167,13 +167,9 @@ static ssize_t i2cdev_write(struct file *file, const char __user *buf, if (count > 8192) count = 8192; - tmp = kmalloc(count, GFP_KERNEL); - if (tmp == NULL) - return -ENOMEM; - if (copy_from_user(tmp, buf, count)) { - kfree(tmp); - return -EFAULT; - } + tmp = memdup_user(buf, count); + if (IS_ERR(tmp)) + return PTR_ERR(tmp); pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n", iminor(file->f_path.dentry->d_inode), count); @@ -245,15 +241,9 @@ static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client, break; } data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf; - rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL); - if (rdwr_pa[i].buf == NULL) { - res = -ENOMEM; - break; - } - if (copy_from_user(rdwr_pa[i].buf, data_ptrs[i], - rdwr_pa[i].len)) { - ++i; /* Needs to be kfreed too */ - res = -EFAULT; + rdwr_pa[i].buf = memdup_user(data_ptrs[i], rdwr_pa[i].len); + if (IS_ERR(rdwr_pa[i].buf)) { + res = PTR_ERR(rdwr_pa[i].buf); break; } } -- cgit v1.2.2 From 9a94241afcc9a481691a9c29b7460217925b59b8 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Wed, 11 Aug 2010 18:20:56 +0200 Subject: i2c: Add support for custom probe function The probe method used by i2c_new_probed_device() may not be suitable for all cases. Let the caller provide its own, optional probe function. Signed-off-by: Jean Delvare Acked-by: Mauro Carvalho Chehab --- drivers/i2c/i2c-core.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index df937df845eb..cf14ca063181 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -1464,14 +1464,18 @@ static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) struct i2c_client * i2c_new_probed_device(struct i2c_adapter *adap, struct i2c_board_info *info, - unsigned short const *addr_list) + unsigned short const *addr_list, + int (*probe)(struct i2c_adapter *, unsigned short addr)) { int i; - /* Stop here if the bus doesn't support probing */ - if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) { - dev_err(&adap->dev, "Probing not supported\n"); - return NULL; + if (!probe) { + /* Stop here if the bus doesn't support probing */ + if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) { + dev_err(&adap->dev, "Probing not supported\n"); + return NULL; + } + probe = i2c_default_probe; } for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { @@ -1490,7 +1494,7 @@ i2c_new_probed_device(struct i2c_adapter *adap, } /* Test address responsiveness */ - if (i2c_default_probe(adap, addr_list[i])) + if (probe(adap, addr_list[i])) break; } -- cgit v1.2.2 From d44f19d586b6113fb5db10e1a36457f0db3b01aa Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Wed, 11 Aug 2010 18:20:57 +0200 Subject: V4L/DVB: Use custom I2C probing function mechanism Now that i2c-core offers the possibility to provide custom probing function for I2C devices, let's make use of it. Signed-off-by: Jean Delvare Acked-by: Mauro Carvalho Chehab --- drivers/i2c/i2c-core.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'drivers/i2c') diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index cf14ca063181..6e1c2f54d9cf 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -1461,6 +1461,13 @@ static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) return err; } +int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr) +{ + return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, + I2C_SMBUS_QUICK, NULL) >= 0; +} +EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read); + struct i2c_client * i2c_new_probed_device(struct i2c_adapter *adap, struct i2c_board_info *info, -- cgit v1.2.2 From fe61e07e9ebc890c70d97a1f72ddaad4bee2d848 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Wed, 11 Aug 2010 18:20:58 +0200 Subject: i2c: Move adapter locking helpers to i2c-core Uninline i2c adapter locking helper functions, move them to i2c-core, and use them in i2c-core itself. The functions are still exported for external users. This makes future updates to the locking model (which will be needed for multiplexing support) possible and transparent. Signed-off-by: Jean Delvare Cc: Michael Lawnick --- drivers/i2c/i2c-core.c | 39 ++++++++++++++++++++++++++++++++++----- 1 file changed, 34 insertions(+), 5 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 6e1c2f54d9cf..e09e143379b1 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -429,6 +429,35 @@ static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) __i2c_check_addr_busy); } +/** + * i2c_lock_adapter - Get exclusive access to an I2C bus segment + * @adapter: Target I2C bus segment + */ +void i2c_lock_adapter(struct i2c_adapter *adapter) +{ + rt_mutex_lock(&adapter->bus_lock); +} +EXPORT_SYMBOL_GPL(i2c_lock_adapter); + +/** + * i2c_trylock_adapter - Try to get exclusive access to an I2C bus segment + * @adapter: Target I2C bus segment + */ +static int i2c_trylock_adapter(struct i2c_adapter *adapter) +{ + return rt_mutex_trylock(&adapter->bus_lock); +} + +/** + * i2c_unlock_adapter - Release exclusive access to an I2C bus segment + * @adapter: Target I2C bus segment + */ +void i2c_unlock_adapter(struct i2c_adapter *adapter) +{ + rt_mutex_unlock(&adapter->bus_lock); +} +EXPORT_SYMBOL_GPL(i2c_unlock_adapter); + /** * i2c_new_device - instantiate an i2c device * @adap: the adapter managing the device @@ -1238,12 +1267,12 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) #endif if (in_atomic() || irqs_disabled()) { - ret = rt_mutex_trylock(&adap->bus_lock); + ret = i2c_trylock_adapter(adap); if (!ret) /* I2C activity is ongoing. */ return -EAGAIN; } else { - rt_mutex_lock(&adap->bus_lock); + i2c_lock_adapter(adap); } /* Retry automatically on arbitration loss */ @@ -1255,7 +1284,7 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) if (time_after(jiffies, orig_jiffies + adap->timeout)) break; } - rt_mutex_unlock(&adap->bus_lock); + i2c_unlock_adapter(adap); return ret; } else { @@ -2013,7 +2042,7 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, flags &= I2C_M_TEN | I2C_CLIENT_PEC; if (adapter->algo->smbus_xfer) { - rt_mutex_lock(&adapter->bus_lock); + i2c_lock_adapter(adapter); /* Retry automatically on arbitration loss */ orig_jiffies = jiffies; @@ -2027,7 +2056,7 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, orig_jiffies + adapter->timeout)) break; } - rt_mutex_unlock(&adapter->bus_lock); + i2c_unlock_adapter(adapter); } else res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write, command, protocol, data); -- cgit v1.2.2 From d6703281ff20df6c2c0ea7c39a0cc2fa8be3e680 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Wed, 11 Aug 2010 18:20:59 +0200 Subject: i2c: Drop dummy variable Now that bus_for_each_drv() is no longer __must_check, we can drop the dummy variable that was used to store the returned value. Signed-off-by: Jean Delvare Cc: Justin P. Mattock --- drivers/i2c/i2c-core.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index e09e143379b1..bb02f8e21a3b 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -789,7 +789,7 @@ static int __process_new_adapter(struct device_driver *d, void *data) static int i2c_register_adapter(struct i2c_adapter *adap) { - int res = 0, dummy; + int res = 0; /* Can't register until after driver model init */ if (unlikely(WARN_ON(!i2c_bus_type.p))) { @@ -830,8 +830,7 @@ static int i2c_register_adapter(struct i2c_adapter *adap) /* Notify drivers */ mutex_lock(&core_lock); - dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap, - __process_new_adapter); + bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); mutex_unlock(&core_lock); return 0; -- cgit v1.2.2 From 8031d79baedabd44590d047d97a310eb0e0e4e0c Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Wed, 11 Aug 2010 18:21:00 +0200 Subject: i2c: Make i2c_default_probe self-sufficient Make i2c_default_probe self-sufficient, so that callers don't have to do functionality checks themselves. This ensures everything is and will stay consistent. Signed-off-by: Jean Delvare --- drivers/i2c/i2c-core.c | 32 ++++++++++---------------------- 1 file changed, 10 insertions(+), 22 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index bb02f8e21a3b..ba86af63f5cf 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -1378,13 +1378,17 @@ static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr) I2C_SMBUS_BYTE_DATA, &dummy); else #endif - if ((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50 - || !i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) - err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, - I2C_SMBUS_BYTE, &dummy); - else + if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50) + && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0, I2C_SMBUS_QUICK, NULL); + else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) + err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, + I2C_SMBUS_BYTE, &dummy); + else { + dev_warn(&adap->dev, "No suitable probing method supported\n"); + err = -EOPNOTSUPP; + } return err >= 0; } @@ -1465,16 +1469,6 @@ static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) if (!(adapter->class & driver->class)) goto exit_free; - /* Stop here if the bus doesn't support probing */ - if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE)) { - if (address_list[0] == I2C_CLIENT_END) - goto exit_free; - - dev_warn(&adapter->dev, "Probing not supported\n"); - err = -EOPNOTSUPP; - goto exit_free; - } - for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { dev_dbg(&adapter->dev, "found normal entry for adapter %d, " "addr 0x%02x\n", adap_id, address_list[i]); @@ -1504,14 +1498,8 @@ i2c_new_probed_device(struct i2c_adapter *adap, { int i; - if (!probe) { - /* Stop here if the bus doesn't support probing */ - if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) { - dev_err(&adap->dev, "Probing not supported\n"); - return NULL; - } + if (!probe) probe = i2c_default_probe; - } for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { /* Check address validity */ -- cgit v1.2.2 From dafc50d141c27959dbd3a1cfe9857a86d23402a7 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Wed, 11 Aug 2010 18:21:01 +0200 Subject: i2c: Use a separate mutex for userspace client lists Moving userspace-instantiated clients to separate lists wasn't nearly enough to avoid deadlocks in multiplexed bus cases. We also want to have a dedicated mutex to protect each list. Signed-off-by: Jean Delvare Cc: Michael Lawnick --- drivers/i2c/i2c-core.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index ba86af63f5cf..97f96b66653c 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -662,9 +662,9 @@ i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, return -EINVAL; /* Keep track of the added device */ - i2c_lock_adapter(adap); + mutex_lock(&adap->userspace_clients_lock); list_add_tail(&client->detected, &adap->userspace_clients); - i2c_unlock_adapter(adap); + mutex_unlock(&adap->userspace_clients_lock); dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", info.type, info.addr); @@ -703,7 +703,7 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, /* Make sure the device was added through sysfs */ res = -ENOENT; - i2c_lock_adapter(adap); + mutex_lock(&adap->userspace_clients_lock); list_for_each_entry_safe(client, next, &adap->userspace_clients, detected) { if (client->addr == addr) { @@ -716,7 +716,7 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, break; } } - i2c_unlock_adapter(adap); + mutex_unlock(&adap->userspace_clients_lock); if (res < 0) dev_err(dev, "%s: Can't find device in list\n", @@ -798,6 +798,7 @@ static int i2c_register_adapter(struct i2c_adapter *adap) } rt_mutex_init(&adap->bus_lock); + mutex_init(&adap->userspace_clients_lock); INIT_LIST_HEAD(&adap->userspace_clients); /* Set default timeout to 1 second if not already set */ @@ -1003,7 +1004,7 @@ int i2c_del_adapter(struct i2c_adapter *adap) return res; /* Remove devices instantiated from sysfs */ - i2c_lock_adapter(adap); + mutex_lock(&adap->userspace_clients_lock); list_for_each_entry_safe(client, next, &adap->userspace_clients, detected) { dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, @@ -1011,7 +1012,7 @@ int i2c_del_adapter(struct i2c_adapter *adap) list_del(&client->detected); i2c_unregister_device(client); } - i2c_unlock_adapter(adap); + mutex_unlock(&adap->userspace_clients_lock); /* Detach any active clients. This can't fail, thus we do not checking the returned value. */ -- cgit v1.2.2 From 0826374bff57411d239f2fcb15da3c35af0a93cd Mon Sep 17 00:00:00 2001 From: Michael Lawnick Date: Wed, 11 Aug 2010 18:21:02 +0200 Subject: i2c: Multiplexed I2C bus core support Add multiplexed bus core support. I2C multiplexer and switches like pca954x get instantiated as new adapters per port. Signed-off-by: Michael Lawnick Acked-by: Rodolfo Giometti Signed-off-by: Jean Delvare --- drivers/i2c/Kconfig | 11 ++++ drivers/i2c/Makefile | 1 + drivers/i2c/i2c-core.c | 64 ++++++++++++++++--- drivers/i2c/i2c-dev.c | 40 +++++++++++- drivers/i2c/i2c-mux.c | 165 +++++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 273 insertions(+), 8 deletions(-) create mode 100644 drivers/i2c/i2c-mux.c (limited to 'drivers/i2c') diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig index d06083fdffbb..efb48ad1ba34 100644 --- a/drivers/i2c/Kconfig +++ b/drivers/i2c/Kconfig @@ -47,6 +47,17 @@ config I2C_CHARDEV This support is also available as a module. If so, the module will be called i2c-dev. +config I2C_MUX + tristate "I2C bus multiplexing support" + depends on EXPERIMENTAL + help + Say Y here if you want the I2C core to support the ability to + handle multiplexed I2C bus topologies, by presenting each + multiplexed segment as a I2C adapter. + + This support is also available as a module. If so, the module + will be called i2c-mux. + config I2C_HELPER_AUTO bool "Autoselect pertinent helper modules" default y diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile index a7d9b4be9bb3..f363258daa3d 100644 --- a/drivers/i2c/Makefile +++ b/drivers/i2c/Makefile @@ -6,6 +6,7 @@ obj-$(CONFIG_I2C_BOARDINFO) += i2c-boardinfo.o obj-$(CONFIG_I2C) += i2c-core.o obj-$(CONFIG_I2C_SMBUS) += i2c-smbus.o obj-$(CONFIG_I2C_CHARDEV) += i2c-dev.o +obj-$(CONFIG_I2C_MUX) += i2c-mux.o obj-y += algos/ busses/ ifeq ($(CONFIG_I2C_DEBUG_CORE),y) diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 97f96b66653c..6649176de940 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -20,7 +20,9 @@ /* With some changes from Kyösti Mälkki . All SMBus-related things are written by Frodo Looijaard SMBus 2.0 support by Mark Studebaker and - Jean Delvare */ + Jean Delvare + Mux support by Rodolfo Giometti and + Michael Lawnick */ #include #include @@ -423,10 +425,48 @@ static int __i2c_check_addr_busy(struct device *dev, void *addrp) return 0; } +/* walk up mux tree */ +static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr) +{ + int result; + + result = device_for_each_child(&adapter->dev, &addr, + __i2c_check_addr_busy); + + if (!result && i2c_parent_is_i2c_adapter(adapter)) + result = i2c_check_mux_parents( + to_i2c_adapter(adapter->dev.parent), addr); + + return result; +} + +/* recurse down mux tree */ +static int i2c_check_mux_children(struct device *dev, void *addrp) +{ + int result; + + if (dev->type == &i2c_adapter_type) + result = device_for_each_child(dev, addrp, + i2c_check_mux_children); + else + result = __i2c_check_addr_busy(dev, addrp); + + return result; +} + static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) { - return device_for_each_child(&adapter->dev, &addr, - __i2c_check_addr_busy); + int result = 0; + + if (i2c_parent_is_i2c_adapter(adapter)) + result = i2c_check_mux_parents( + to_i2c_adapter(adapter->dev.parent), addr); + + if (!result) + result = device_for_each_child(&adapter->dev, &addr, + i2c_check_mux_children); + + return result; } /** @@ -435,7 +475,10 @@ static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) */ void i2c_lock_adapter(struct i2c_adapter *adapter) { - rt_mutex_lock(&adapter->bus_lock); + if (i2c_parent_is_i2c_adapter(adapter)) + i2c_lock_adapter(to_i2c_adapter(adapter->dev.parent)); + else + rt_mutex_lock(&adapter->bus_lock); } EXPORT_SYMBOL_GPL(i2c_lock_adapter); @@ -445,7 +488,10 @@ EXPORT_SYMBOL_GPL(i2c_lock_adapter); */ static int i2c_trylock_adapter(struct i2c_adapter *adapter) { - return rt_mutex_trylock(&adapter->bus_lock); + if (i2c_parent_is_i2c_adapter(adapter)) + return i2c_trylock_adapter(to_i2c_adapter(adapter->dev.parent)); + else + return rt_mutex_trylock(&adapter->bus_lock); } /** @@ -454,7 +500,10 @@ static int i2c_trylock_adapter(struct i2c_adapter *adapter) */ void i2c_unlock_adapter(struct i2c_adapter *adapter) { - rt_mutex_unlock(&adapter->bus_lock); + if (i2c_parent_is_i2c_adapter(adapter)) + i2c_unlock_adapter(to_i2c_adapter(adapter->dev.parent)); + else + rt_mutex_unlock(&adapter->bus_lock); } EXPORT_SYMBOL_GPL(i2c_unlock_adapter); @@ -743,10 +792,11 @@ static const struct attribute_group *i2c_adapter_attr_groups[] = { NULL }; -static struct device_type i2c_adapter_type = { +struct device_type i2c_adapter_type = { .groups = i2c_adapter_attr_groups, .release = i2c_adapter_dev_release, }; +EXPORT_SYMBOL_GPL(i2c_adapter_type); #ifdef CONFIG_I2C_COMPAT static struct class_compat *i2c_adapter_compat_class; diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c index 0b0427f7d348..5f3a52d517c3 100644 --- a/drivers/i2c/i2c-dev.c +++ b/drivers/i2c/i2c-dev.c @@ -189,12 +189,50 @@ static int i2cdev_check(struct device *dev, void *addrp) return dev->driver ? -EBUSY : 0; } +/* walk up mux tree */ +static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr) +{ + int result; + + result = device_for_each_child(&adapter->dev, &addr, i2cdev_check); + + if (!result && i2c_parent_is_i2c_adapter(adapter)) + result = i2cdev_check_mux_parents( + to_i2c_adapter(adapter->dev.parent), addr); + + return result; +} + +/* recurse down mux tree */ +static int i2cdev_check_mux_children(struct device *dev, void *addrp) +{ + int result; + + if (dev->type == &i2c_adapter_type) + result = device_for_each_child(dev, addrp, + i2cdev_check_mux_children); + else + result = i2cdev_check(dev, addrp); + + return result; +} + /* This address checking function differs from the one in i2c-core in that it considers an address with a registered device, but no driver bound to it, as NOT busy. */ static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr) { - return device_for_each_child(&adapter->dev, &addr, i2cdev_check); + int result = 0; + + if (i2c_parent_is_i2c_adapter(adapter)) + result = i2cdev_check_mux_parents( + to_i2c_adapter(adapter->dev.parent), addr); + + if (!result) + result = device_for_each_child(&adapter->dev, &addr, + i2cdev_check_mux_children); + + return result; } static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client, diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c new file mode 100644 index 000000000000..d32a4843fc3a --- /dev/null +++ b/drivers/i2c/i2c-mux.c @@ -0,0 +1,165 @@ +/* + * Multiplexed I2C bus driver. + * + * Copyright (c) 2008-2009 Rodolfo Giometti + * Copyright (c) 2008-2009 Eurotech S.p.A. + * Copyright (c) 2009-2010 NSN GmbH & Co KG + * + * Simplifies access to complex multiplexed I2C bus topologies, by presenting + * each multiplexed bus segment as an additional I2C adapter. + * Supports multi-level mux'ing (mux behind a mux). + * + * Based on: + * i2c-virt.c from Kumar Gala + * i2c-virtual.c from Ken Harrenstien, Copyright (c) 2004 Google, Inc. + * i2c-virtual.c from Brian Kuschak + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include +#include +#include +#include +#include + +/* multiplexer per channel data */ +struct i2c_mux_priv { + struct i2c_adapter adap; + struct i2c_algorithm algo; + + struct i2c_adapter *parent; + void *mux_dev; /* the mux chip/device */ + u32 chan_id; /* the channel id */ + + int (*select)(struct i2c_adapter *, void *mux_dev, u32 chan_id); + int (*deselect)(struct i2c_adapter *, void *mux_dev, u32 chan_id); +}; + +static int i2c_mux_master_xfer(struct i2c_adapter *adap, + struct i2c_msg msgs[], int num) +{ + struct i2c_mux_priv *priv = adap->algo_data; + struct i2c_adapter *parent = priv->parent; + int ret; + + /* Switch to the right mux port and perform the transfer. */ + + ret = priv->select(parent, priv->mux_dev, priv->chan_id); + if (ret >= 0) + ret = parent->algo->master_xfer(parent, msgs, num); + if (priv->deselect) + priv->deselect(parent, priv->mux_dev, priv->chan_id); + + return ret; +} + +static int i2c_mux_smbus_xfer(struct i2c_adapter *adap, + u16 addr, unsigned short flags, + char read_write, u8 command, + int size, union i2c_smbus_data *data) +{ + struct i2c_mux_priv *priv = adap->algo_data; + struct i2c_adapter *parent = priv->parent; + int ret; + + /* Select the right mux port and perform the transfer. */ + + ret = priv->select(parent, priv->mux_dev, priv->chan_id); + if (ret >= 0) + ret = parent->algo->smbus_xfer(parent, addr, flags, + read_write, command, size, data); + if (priv->deselect) + priv->deselect(parent, priv->mux_dev, priv->chan_id); + + return ret; +} + +/* Return the parent's functionality */ +static u32 i2c_mux_functionality(struct i2c_adapter *adap) +{ + struct i2c_mux_priv *priv = adap->algo_data; + struct i2c_adapter *parent = priv->parent; + + return parent->algo->functionality(parent); +} + +struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent, + void *mux_dev, u32 force_nr, u32 chan_id, + int (*select) (struct i2c_adapter *, + void *, u32), + int (*deselect) (struct i2c_adapter *, + void *, u32)) +{ + struct i2c_mux_priv *priv; + int ret; + + priv = kzalloc(sizeof(struct i2c_mux_priv), GFP_KERNEL); + if (!priv) + return NULL; + + /* Set up private adapter data */ + priv->parent = parent; + priv->mux_dev = mux_dev; + priv->chan_id = chan_id; + priv->select = select; + priv->deselect = deselect; + + /* Need to do algo dynamically because we don't know ahead + * of time what sort of physical adapter we'll be dealing with. + */ + if (parent->algo->master_xfer) + priv->algo.master_xfer = i2c_mux_master_xfer; + if (parent->algo->smbus_xfer) + priv->algo.smbus_xfer = i2c_mux_smbus_xfer; + priv->algo.functionality = i2c_mux_functionality; + + /* Now fill out new adapter structure */ + snprintf(priv->adap.name, sizeof(priv->adap.name), + "i2c-%d-mux (chan_id %d)", i2c_adapter_id(parent), chan_id); + priv->adap.owner = THIS_MODULE; + priv->adap.id = parent->id; + priv->adap.algo = &priv->algo; + priv->adap.algo_data = priv; + priv->adap.dev.parent = &parent->dev; + + if (force_nr) { + priv->adap.nr = force_nr; + ret = i2c_add_numbered_adapter(&priv->adap); + } else { + ret = i2c_add_adapter(&priv->adap); + } + if (ret < 0) { + dev_err(&parent->dev, + "failed to add mux-adapter (error=%d)\n", + ret); + kfree(priv); + return NULL; + } + + dev_info(&parent->dev, "Added multiplexed i2c bus %d\n", + i2c_adapter_id(&priv->adap)); + + return &priv->adap; +} +EXPORT_SYMBOL_GPL(i2c_add_mux_adapter); + +int i2c_del_mux_adapter(struct i2c_adapter *adap) +{ + struct i2c_mux_priv *priv = adap->algo_data; + int ret; + + ret = i2c_del_adapter(adap); + if (ret < 0) + return ret; + kfree(priv); + + return 0; +} +EXPORT_SYMBOL_GPL(i2c_del_mux_adapter); + +MODULE_AUTHOR("Rodolfo Giometti "); +MODULE_DESCRIPTION("I2C driver for multiplexed I2C busses"); +MODULE_LICENSE("GPL v2"); -- cgit v1.2.2 From 7f528135da9704d67db1f727162024b078e1cd8f Mon Sep 17 00:00:00 2001 From: Michael Lawnick Date: Wed, 11 Aug 2010 18:21:03 +0200 Subject: i2c: I2C bus multiplexer driver pca954x I2C driver for PCA954x I2C multiplexer series. Signed-off-by: Michael Lawnick Acked-by: Rodolfo Giometti Signed-off-by: Jean Delvare --- drivers/i2c/Kconfig | 2 + drivers/i2c/Makefile | 2 +- drivers/i2c/muxes/Kconfig | 18 +++ drivers/i2c/muxes/Makefile | 8 ++ drivers/i2c/muxes/pca954x.c | 301 ++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 330 insertions(+), 1 deletion(-) create mode 100644 drivers/i2c/muxes/Kconfig create mode 100644 drivers/i2c/muxes/Makefile create mode 100644 drivers/i2c/muxes/pca954x.c (limited to 'drivers/i2c') diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig index efb48ad1ba34..30f06e956bfb 100644 --- a/drivers/i2c/Kconfig +++ b/drivers/i2c/Kconfig @@ -58,6 +58,8 @@ config I2C_MUX This support is also available as a module. If so, the module will be called i2c-mux. +source drivers/i2c/muxes/Kconfig + config I2C_HELPER_AUTO bool "Autoselect pertinent helper modules" default y diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile index f363258daa3d..c00fd66388f5 100644 --- a/drivers/i2c/Makefile +++ b/drivers/i2c/Makefile @@ -7,7 +7,7 @@ obj-$(CONFIG_I2C) += i2c-core.o obj-$(CONFIG_I2C_SMBUS) += i2c-smbus.o obj-$(CONFIG_I2C_CHARDEV) += i2c-dev.o obj-$(CONFIG_I2C_MUX) += i2c-mux.o -obj-y += algos/ busses/ +obj-y += algos/ busses/ muxes/ ifeq ($(CONFIG_I2C_DEBUG_CORE),y) EXTRA_CFLAGS += -DDEBUG diff --git a/drivers/i2c/muxes/Kconfig b/drivers/i2c/muxes/Kconfig new file mode 100644 index 000000000000..4c9a99c4fcb0 --- /dev/null +++ b/drivers/i2c/muxes/Kconfig @@ -0,0 +1,18 @@ +# +# Multiplexer I2C chip drivers configuration +# + +menu "Multiplexer I2C Chip support" + depends on I2C_MUX + +config I2C_MUX_PCA954x + tristate "Philips PCA954x I2C Mux/switches" + depends on EXPERIMENTAL + help + If you say yes here you get support for the Philips PCA954x + I2C mux/switch devices. + + This driver can also be built as a module. If so, the module + will be called pca954x. + +endmenu diff --git a/drivers/i2c/muxes/Makefile b/drivers/i2c/muxes/Makefile new file mode 100644 index 000000000000..bd83b5274815 --- /dev/null +++ b/drivers/i2c/muxes/Makefile @@ -0,0 +1,8 @@ +# +# Makefile for multiplexer I2C chip drivers. + +obj-$(CONFIG_I2C_MUX_PCA954x) += pca954x.o + +ifeq ($(CONFIG_I2C_DEBUG_BUS),y) +EXTRA_CFLAGS += -DDEBUG +endif diff --git a/drivers/i2c/muxes/pca954x.c b/drivers/i2c/muxes/pca954x.c new file mode 100644 index 000000000000..6f9accf3189d --- /dev/null +++ b/drivers/i2c/muxes/pca954x.c @@ -0,0 +1,301 @@ +/* + * I2C multiplexer + * + * Copyright (c) 2008-2009 Rodolfo Giometti + * Copyright (c) 2008-2009 Eurotech S.p.A. + * + * This module supports the PCA954x series of I2C multiplexer/switch chips + * made by Philips Semiconductors. + * This includes the: + * PCA9540, PCA9542, PCA9543, PCA9544, PCA9545, PCA9546, PCA9547 + * and PCA9548. + * + * These chips are all controlled via the I2C bus itself, and all have a + * single 8-bit register. The upstream "parent" bus fans out to two, + * four, or eight downstream busses or channels; which of these + * are selected is determined by the chip type and register contents. A + * mux can select only one sub-bus at a time; a switch can select any + * combination simultaneously. + * + * Based on: + * pca954x.c from Kumar Gala + * Copyright (C) 2006 + * + * Based on: + * pca954x.c from Ken Harrenstien + * Copyright (C) 2004 Google, Inc. (Ken Harrenstien) + * + * Based on: + * i2c-virtual_cb.c from Brian Kuschak + * and + * pca9540.c from Jean Delvare . + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include +#include +#include +#include +#include +#include + +#include + +#define PCA954X_MAX_NCHANS 8 + +enum pca_type { + pca_9540, + pca_9542, + pca_9543, + pca_9544, + pca_9545, + pca_9546, + pca_9547, + pca_9548, +}; + +struct pca954x { + enum pca_type type; + struct i2c_adapter *virt_adaps[PCA954X_MAX_NCHANS]; + + u8 last_chan; /* last register value */ +}; + +struct chip_desc { + u8 nchans; + u8 enable; /* used for muxes only */ + enum muxtype { + pca954x_ismux = 0, + pca954x_isswi + } muxtype; +}; + +/* Provide specs for the PCA954x types we know about */ +static const struct chip_desc chips[] = { + [pca_9540] = { + .nchans = 2, + .enable = 0x4, + .muxtype = pca954x_ismux, + }, + [pca_9543] = { + .nchans = 2, + .muxtype = pca954x_isswi, + }, + [pca_9544] = { + .nchans = 4, + .enable = 0x4, + .muxtype = pca954x_ismux, + }, + [pca_9545] = { + .nchans = 4, + .muxtype = pca954x_isswi, + }, + [pca_9547] = { + .nchans = 8, + .enable = 0x8, + .muxtype = pca954x_ismux, + }, + [pca_9548] = { + .nchans = 8, + .muxtype = pca954x_isswi, + }, +}; + +static const struct i2c_device_id pca954x_id[] = { + { "pca9540", pca_9540 }, + { "pca9542", pca_9540 }, + { "pca9543", pca_9543 }, + { "pca9544", pca_9544 }, + { "pca9545", pca_9545 }, + { "pca9546", pca_9545 }, + { "pca9547", pca_9547 }, + { "pca9548", pca_9548 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, pca954x_id); + +/* Write to mux register. Don't use i2c_transfer()/i2c_smbus_xfer() + for this as they will try to lock adapter a second time */ +static int pca954x_reg_write(struct i2c_adapter *adap, + struct i2c_client *client, u8 val) +{ + int ret = -ENODEV; + + if (adap->algo->master_xfer) { + struct i2c_msg msg; + char buf[1]; + + msg.addr = client->addr; + msg.flags = 0; + msg.len = 1; + buf[0] = val; + msg.buf = buf; + ret = adap->algo->master_xfer(adap, &msg, 1); + } else { + union i2c_smbus_data data; + ret = adap->algo->smbus_xfer(adap, client->addr, + client->flags, + I2C_SMBUS_WRITE, + val, I2C_SMBUS_BYTE, &data); + } + + return ret; +} + +static int pca954x_select_chan(struct i2c_adapter *adap, + void *client, u32 chan) +{ + struct pca954x *data = i2c_get_clientdata(client); + const struct chip_desc *chip = &chips[data->type]; + u8 regval; + int ret = 0; + + /* we make switches look like muxes, not sure how to be smarter */ + if (chip->muxtype == pca954x_ismux) + regval = chan | chip->enable; + else + regval = 1 << chan; + + /* Only select the channel if its different from the last channel */ + if (data->last_chan != regval) { + ret = pca954x_reg_write(adap, client, regval); + data->last_chan = regval; + } + + return ret; +} + +static int pca954x_deselect_mux(struct i2c_adapter *adap, + void *client, u32 chan) +{ + struct pca954x *data = i2c_get_clientdata(client); + + /* Deselect active channel */ + data->last_chan = 0; + return pca954x_reg_write(adap, client, data->last_chan); +} + +/* + * I2C init/probing/exit functions + */ +static int __devinit pca954x_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct i2c_adapter *adap = to_i2c_adapter(client->dev.parent); + struct pca954x_platform_data *pdata = client->dev.platform_data; + int num, force; + struct pca954x *data; + int ret = -ENODEV; + + if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE)) + goto err; + + data = kzalloc(sizeof(struct pca954x), GFP_KERNEL); + if (!data) { + ret = -ENOMEM; + goto err; + } + + i2c_set_clientdata(client, data); + + /* Read the mux register at addr to verify + * that the mux is in fact present. + */ + if (i2c_smbus_read_byte(client) < 0) { + dev_warn(&client->dev, "probe failed\n"); + goto exit_free; + } + + data->type = id->driver_data; + data->last_chan = 0; /* force the first selection */ + + /* Now create an adapter for each channel */ + for (num = 0; num < chips[data->type].nchans; num++) { + force = 0; /* dynamic adap number */ + if (pdata) { + if (num < pdata->num_modes) + /* force static number */ + force = pdata->modes[num].adap_id; + else + /* discard unconfigured channels */ + break; + } + + data->virt_adaps[num] = + i2c_add_mux_adapter(adap, client, + force, num, pca954x_select_chan, + (pdata && pdata->modes[num].deselect_on_exit) + ? pca954x_deselect_mux : NULL); + + if (data->virt_adaps[num] == NULL) { + ret = -ENODEV; + dev_err(&client->dev, + "failed to register multiplexed adapter" + " %d as bus %d\n", num, force); + goto virt_reg_failed; + } + } + + dev_info(&client->dev, + "registered %d multiplexed busses for I2C %s %s\n", + num, chips[data->type].muxtype == pca954x_ismux + ? "mux" : "switch", client->name); + + return 0; + +virt_reg_failed: + for (num--; num >= 0; num--) + i2c_del_mux_adapter(data->virt_adaps[num]); +exit_free: + kfree(data); +err: + return ret; +} + +static int __devexit pca954x_remove(struct i2c_client *client) +{ + struct pca954x *data = i2c_get_clientdata(client); + const struct chip_desc *chip = &chips[data->type]; + int i, err; + + for (i = 0; i < chip->nchans; ++i) + if (data->virt_adaps[i]) { + err = i2c_del_mux_adapter(data->virt_adaps[i]); + if (err) + return err; + data->virt_adaps[i] = NULL; + } + + kfree(data); + return 0; +} + +static struct i2c_driver pca954x_driver = { + .driver = { + .name = "pca954x", + .owner = THIS_MODULE, + }, + .probe = pca954x_probe, + .remove = __devexit_p(pca954x_remove), + .id_table = pca954x_id, +}; + +static int __init pca954x_init(void) +{ + return i2c_add_driver(&pca954x_driver); +} + +static void __exit pca954x_exit(void) +{ + i2c_del_driver(&pca954x_driver); +} + +module_init(pca954x_init); +module_exit(pca954x_exit); + +MODULE_AUTHOR("Rodolfo Giometti "); +MODULE_DESCRIPTION("PCA954x I2C mux/switch driver"); +MODULE_LICENSE("GPL v2"); -- cgit v1.2.2