| Message ID | 20090331124035.908249543@denx.de (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
On Tue, Mar 31, 2009 at 6:37 AM, Wolfgang Grandegger <wg@grandegger.com> wrote: > This patch makes the I2C bus speed configurable by using the I2C node > property "clock-frequency". If the property is not defined, the old > fixed clock settings will be used for backward comptibility. > > The generic I2C clock properties, especially the CPU-specific source > clock pre-scaler are defined via the OF match table: > > static const struct of_device_id mpc_i2c_of_match[] = { > {.compatible = "fsl,mpc5200b-i2c", > .data = (void *)FSL_I2C_DEV_CLOCK_5200, }, > {.compatible = "fsl,mpc5200-i2c", > .data = (void *)FSL_I2C_DEV_CLOCK_5200, }, > {.compatible = "fsl,mpc8313-i2c", > .data = (void *)FSL_I2C_DEV_SEPARATE_DFSRR, }, > {.compatible = "fsl,mpc8543-i2c", > .data = (void *)(FSL_I2C_DEV_SEPARATE_DFSRR | > FSL_I2C_DEV_CLOCK_DIV2), }, > {.compatible = "fsl,mpc8544-i2c", > .data = (void *)(FSL_I2C_DEV_SEPARATE_DFSRR | > FSL_I2C_DEV_CLOCK_DIV23), }, > /* Backward compatibility */ > {.compatible = "fsl-i2c", }, > {}, > }; Instead passing in a flag (and using an ugly cast to do it) which is then checked inside the mpc_i2c_setclock(), you should do this instead: struct fsl_i2c_match_data { int static void *(setclock)(struct device_node *node, struct mpc_i2c *i2c, u32 clock); int flags; /* Other stuff can go here */ }; static const struct of_device_id mpc_i2c_of_match[] = { {.compatible = "fsl,mpc5200b-i2c", .data = (struct fsl_i2c_match_data[]) { .setclock = mpc_i2c_setclock_mpc5200, }, }, {.compatible = "fsl,mpc5200-i2c", .data = (struct fsl_i2c_match_data[]) { .setclock = mpc_i2c_setclock_mpc5200, }, }, {.compatible = "fsl,mpc8313-i2c", .data = (struct fsl_i2c_match_data[]) { .setclock = mpc_i2c_setclock_separate_dfsrr, }, }, {.compatible = "fsl,mpc8543-i2c", .data = (struct fsl_i2c_match_data[]) { .setclock = mpc_i2c_setclock_separate_dfsrr, }, .flags = FSL_I2C_DEV_CLOCK_DIV2, }, {.compatible = "fsl,mpc8544-i2c", .data = (struct fsl_i2c_match_data[]) { .setclock = mpc_i2c_setclock_separate_dfsrr, }, .flags = FSL_I2C_DEV_CLOCK_DIV23, }, /* Backward compatibility */ {.compatible = "fsl-i2c", .data = (struct fsl_i2c_match_data[]) { .setclock = mpc_i2c_setclock, }, }, {}, }; The table definition is more verbose this way, but I think it results in more understandable and easier to extend code. It also adds lets the compiler do more type checking for you. Also, this ... > --- linux-2.6.orig/arch/powerpc/sysdev/fsl_soc.c 2009-03-31 13:25:08.000000000 +0200 > +++ linux-2.6/arch/powerpc/sysdev/fsl_soc.c 2009-03-31 13:34:40.531721011 +0200 > +int fsl_i2c_get_fdr(struct device_node *node, u32 i2c_clock, u32 i2c_flags) > +{ > [...] > +} > +EXPORT_SYMBOL(fsl_i2c_get_fdr); ... and this ... > --- linux-2.6.orig/arch/powerpc/platforms/52xx/mpc52xx_common.c 2009-03-31 13:25:08.000000000 +0200 > +++ linux-2.6/arch/powerpc/platforms/52xx/mpc52xx_common.c 2009-03-31 13:28:54.309718526 +0200 > +int fsl_i2c_get_fdr(struct device_node *node, u32 i2c_clock, u32 i2c_flags) > +{ > [...] > +} > +EXPORT_SYMBOL(fsl_i2c_get_fdr); does not work on a multiplatform kernel. Both 8xxx and 52xx support can be selected at the same time. g.
Grant Likely wrote: > On Tue, Mar 31, 2009 at 6:37 AM, Wolfgang Grandegger <wg@grandegger.com> wrote: >> This patch makes the I2C bus speed configurable by using the I2C node >> property "clock-frequency". If the property is not defined, the old >> fixed clock settings will be used for backward comptibility. >> >> The generic I2C clock properties, especially the CPU-specific source >> clock pre-scaler are defined via the OF match table: >> >> static const struct of_device_id mpc_i2c_of_match[] = { >> {.compatible = "fsl,mpc5200b-i2c", >> .data = (void *)FSL_I2C_DEV_CLOCK_5200, }, >> {.compatible = "fsl,mpc5200-i2c", >> .data = (void *)FSL_I2C_DEV_CLOCK_5200, }, >> {.compatible = "fsl,mpc8313-i2c", >> .data = (void *)FSL_I2C_DEV_SEPARATE_DFSRR, }, >> {.compatible = "fsl,mpc8543-i2c", >> .data = (void *)(FSL_I2C_DEV_SEPARATE_DFSRR | >> FSL_I2C_DEV_CLOCK_DIV2), }, >> {.compatible = "fsl,mpc8544-i2c", >> .data = (void *)(FSL_I2C_DEV_SEPARATE_DFSRR | >> FSL_I2C_DEV_CLOCK_DIV23), }, >> /* Backward compatibility */ >> {.compatible = "fsl-i2c", }, >> {}, >> }; > > > Instead passing in a flag (and using an ugly cast to do it) which is > then checked inside the mpc_i2c_setclock(), you should do this > instead: > > struct fsl_i2c_match_data { > int static void *(setclock)(struct device_node *node, struct > mpc_i2c *i2c, u32 clock); > int flags; > /* Other stuff can go here */ > }; > > static const struct of_device_id mpc_i2c_of_match[] = { > {.compatible = "fsl,mpc5200b-i2c", > .data = (struct fsl_i2c_match_data[]) { .setclock = > mpc_i2c_setclock_mpc5200, }, > }, > {.compatible = "fsl,mpc5200-i2c", > .data = (struct fsl_i2c_match_data[]) { .setclock = > mpc_i2c_setclock_mpc5200, }, > }, > {.compatible = "fsl,mpc8313-i2c", > .data = (struct fsl_i2c_match_data[]) { .setclock = > mpc_i2c_setclock_separate_dfsrr, }, > }, > {.compatible = "fsl,mpc8543-i2c", > .data = (struct fsl_i2c_match_data[]) { .setclock = > mpc_i2c_setclock_separate_dfsrr, }, > .flags = FSL_I2C_DEV_CLOCK_DIV2, > }, > {.compatible = "fsl,mpc8544-i2c", > .data = (struct fsl_i2c_match_data[]) { .setclock = > mpc_i2c_setclock_separate_dfsrr, }, > .flags = FSL_I2C_DEV_CLOCK_DIV23, > }, > /* Backward compatibility */ > {.compatible = "fsl-i2c", > .data = (struct fsl_i2c_match_data[]) { .setclock = > mpc_i2c_setclock, }, > }, > {}, > }; > > The table definition is more verbose this way, but I think it results > in more understandable and easier to extend code. It also adds lets > the compiler do more type checking for you. OK but I don't like the callback function to do the settings. We need backward compatibility with old DTS files including the ugly "dfsrr" property, right? Then it seems consequent to continue using i2c->flags for that purpose and not to introduce another method. If we don't need backward compatibility, we could drop the flags completely and just use callback functions. > Also, this ... > >> --- linux-2.6.orig/arch/powerpc/sysdev/fsl_soc.c 2009-03-31 13:25:08.000000000 +0200 >> +++ linux-2.6/arch/powerpc/sysdev/fsl_soc.c 2009-03-31 13:34:40.531721011 +0200 >> +int fsl_i2c_get_fdr(struct device_node *node, u32 i2c_clock, u32 i2c_flags) >> +{ >> [...] >> +} >> +EXPORT_SYMBOL(fsl_i2c_get_fdr); > > ... and this ... > >> --- linux-2.6.orig/arch/powerpc/platforms/52xx/mpc52xx_common.c 2009-03-31 13:25:08.000000000 +0200 >> +++ linux-2.6/arch/powerpc/platforms/52xx/mpc52xx_common.c 2009-03-31 13:28:54.309718526 +0200 >> +int fsl_i2c_get_fdr(struct device_node *node, u32 i2c_clock, u32 i2c_flags) >> +{ >> [...] >> +} >> +EXPORT_SYMBOL(fsl_i2c_get_fdr); > > does not work on a multiplatform kernel. Both 8xxx and 52xx support > can be selected at the same time. OK, then we need different functions including stubs. Wolfgang.
On Wed, Apr 1, 2009 at 1:51 AM, Wolfgang Grandegger <wg@grandegger.com> wrote: > Grant Likely wrote: >> The table definition is more verbose this way, but I think it results >> in more understandable and easier to extend code. It also adds lets >> the compiler do more type checking for you. > > OK but I don't like the callback function to do the settings. We need > backward compatibility with old DTS files including the ugly "dfsrr" > property, right? Then it seems consequent to continue using i2c->flags > for that purpose and not to introduce another method. If we don't need > backward compatibility, we could drop the flags completely and just use > callback functions. I don't understand why you don't like it. It's an elegant solution and it simplifies the code somewhat. After grabbing the callback pointer the compatibility code can simply override it. But I won't belabor the point or oppose the patch if you stick with the flags pointer. >>> --- linux-2.6.orig/arch/powerpc/platforms/52xx/mpc52xx_common.c 2009-03-31 13:25:08.000000000 +0200 >>> +++ linux-2.6/arch/powerpc/platforms/52xx/mpc52xx_common.c 2009-03-31 13:28:54.309718526 +0200 >>> +int fsl_i2c_get_fdr(struct device_node *node, u32 i2c_clock, u32 i2c_flags) >>> +{ >>> [...] >>> +} >>> +EXPORT_SYMBOL(fsl_i2c_get_fdr); >> >> does not work on a multiplatform kernel. Both 8xxx and 52xx support >> can be selected at the same time. > > OK, then we need different functions including stubs. I've been thinking about this more. These tables are only ever going to be used by the i2c_mpc driver and so really they are a part of the i2c_mpc driver itself. Putting them into common code doesn't make any sense because it is not common code. I will not merge a patch that puts them into mpc5200 common code. g.
Grant Likely wrote: > On Wed, Apr 1, 2009 at 1:51 AM, Wolfgang Grandegger <wg@grandegger.com> wrote: >> Grant Likely wrote: >>> The table definition is more verbose this way, but I think it results >>> in more understandable and easier to extend code. It also adds lets >>> the compiler do more type checking for you. >> OK but I don't like the callback function to do the settings. We need >> backward compatibility with old DTS files including the ugly "dfsrr" >> property, right? Then it seems consequent to continue using i2c->flags >> for that purpose and not to introduce another method. If we don't need >> backward compatibility, we could drop the flags completely and just use >> callback functions. > > I don't understand why you don't like it. It's an elegant solution > and it simplifies the code somewhat. After grabbing the callback > pointer the compatibility code can simply override it. But I won't > belabor the point or oppose the patch if you stick with the flags > pointer. I changed my mind ;-). Have a look to PATCH v2 I sent out a few minutes ago. >>>> --- linux-2.6.orig/arch/powerpc/platforms/52xx/mpc52xx_common.c 2009-03-31 13:25:08.000000000 +0200 >>>> +++ linux-2.6/arch/powerpc/platforms/52xx/mpc52xx_common.c 2009-03-31 13:28:54.309718526 +0200 >>>> +int fsl_i2c_get_fdr(struct device_node *node, u32 i2c_clock, u32 i2c_flags) >>>> +{ >>>> [...] >>>> +} >>>> +EXPORT_SYMBOL(fsl_i2c_get_fdr); >>> does not work on a multiplatform kernel. Both 8xxx and 52xx support >>> can be selected at the same time. >> OK, then we need different functions including stubs. > > I've been thinking about this more. These tables are only ever going > to be used by the i2c_mpc driver and so really they are a part of the > i2c_mpc driver itself. Putting them into common code doesn't make any > sense because it is not common code. I will not merge a patch that > puts them into mpc5200 common code. It's not common code, I agree. How about putting it into mpc52xx_i2c.c and use: $ cat Makefile obj-$(CONFIG_I2C_MPC) += mpc52xx_i2c.o Or it could be moved back to the i2c_mpc driver and we add stubs for the functions to get the bus frequency, or use #ifdef's. Wolfgang.
Wolfgang Grandegger wrote: > Grant Likely wrote: >> On Wed, Apr 1, 2009 at 1:51 AM, Wolfgang Grandegger <wg@grandegger.com> wrote: >>> Grant Likely wrote: >>>> The table definition is more verbose this way, but I think it results >>>> in more understandable and easier to extend code. It also adds lets >>>> the compiler do more type checking for you. >>> OK but I don't like the callback function to do the settings. We need >>> backward compatibility with old DTS files including the ugly "dfsrr" >>> property, right? Then it seems consequent to continue using i2c->flags >>> for that purpose and not to introduce another method. If we don't need >>> backward compatibility, we could drop the flags completely and just use >>> callback functions. >> I don't understand why you don't like it. It's an elegant solution >> and it simplifies the code somewhat. After grabbing the callback >> pointer the compatibility code can simply override it. But I won't >> belabor the point or oppose the patch if you stick with the flags >> pointer. > > I changed my mind ;-). Have a look to PATCH v2 I sent out a few minutes ago. > >>>>> --- linux-2.6.orig/arch/powerpc/platforms/52xx/mpc52xx_common.c 2009-03-31 13:25:08.000000000 +0200 >>>>> +++ linux-2.6/arch/powerpc/platforms/52xx/mpc52xx_common.c 2009-03-31 13:28:54.309718526 +0200 >>>>> +int fsl_i2c_get_fdr(struct device_node *node, u32 i2c_clock, u32 i2c_flags) >>>>> +{ >>>>> [...] >>>>> +} >>>>> +EXPORT_SYMBOL(fsl_i2c_get_fdr); >>>> does not work on a multiplatform kernel. Both 8xxx and 52xx support >>>> can be selected at the same time. >>> OK, then we need different functions including stubs. >> I've been thinking about this more. These tables are only ever going >> to be used by the i2c_mpc driver and so really they are a part of the >> i2c_mpc driver itself. Putting them into common code doesn't make any >> sense because it is not common code. I will not merge a patch that >> puts them into mpc5200 common code. > > It's not common code, I agree. How about putting it into mpc52xx_i2c.c > and use: > > $ cat Makefile > obj-$(CONFIG_I2C_MPC) += mpc52xx_i2c.o That not a good idea either. I just checked the I2C interface of the MPC512x and it can use the same table then the MPC5200B. Wolfgang.
On Wed, Apr 1, 2009 at 7:41 AM, Wolfgang Grandegger <wg@grandegger.com> wrote: > Grant Likely wrote: >> On Wed, Apr 1, 2009 at 1:51 AM, Wolfgang Grandegger <wg@grandegger.com> wrote: >>> Grant Likely wrote: >>>> The table definition is more verbose this way, but I think it results >>>> in more understandable and easier to extend code. It also adds lets >>>> the compiler do more type checking for you. >>> OK but I don't like the callback function to do the settings. We need >>> backward compatibility with old DTS files including the ugly "dfsrr" >>> property, right? Then it seems consequent to continue using i2c->flags >>> for that purpose and not to introduce another method. If we don't need >>> backward compatibility, we could drop the flags completely and just use >>> callback functions. >> >> I don't understand why you don't like it. It's an elegant solution >> and it simplifies the code somewhat. After grabbing the callback >> pointer the compatibility code can simply override it. But I won't >> belabor the point or oppose the patch if you stick with the flags >> pointer. > > I changed my mind ;-). Have a look to PATCH v2 I sent out a few minutes ago. I saw and I like. :-) >> I've been thinking about this more. These tables are only ever going >> to be used by the i2c_mpc driver and so really they are a part of the >> i2c_mpc driver itself. Putting them into common code doesn't make any >> sense because it is not common code. I will not merge a patch that >> puts them into mpc5200 common code. > > It's not common code, I agree. How about putting it into mpc52xx_i2c.c > and use: > > $ cat Makefile > obj-$(CONFIG_I2C_MPC) += mpc52xx_i2c.o > > Or it could be moved back to the i2c_mpc driver and we add stubs for the > functions to get the bus frequency, or use #ifdef's. I'm happy with either as long as it lives in the same directory as the i2c_mpc driver, and as long as the i2c maintainers are okay with it. Oh, and if you use a separate file it should be statically linked into the i2c_mpc module using the i2c_mpc-$(CONFIG_WHATEVER) trick. No EXPORT_SYMBOLS should be needed. g.
Grant Likely wrote: > On Wed, Apr 1, 2009 at 7:41 AM, Wolfgang Grandegger <wg@grandegger.com> wrote: >> Grant Likely wrote: >>> On Wed, Apr 1, 2009 at 1:51 AM, Wolfgang Grandegger <wg@grandegger.com> wrote: >>>> Grant Likely wrote: >>>>> The table definition is more verbose this way, but I think it results >>>>> in more understandable and easier to extend code. It also adds lets >>>>> the compiler do more type checking for you. >>>> OK but I don't like the callback function to do the settings. We need >>>> backward compatibility with old DTS files including the ugly "dfsrr" >>>> property, right? Then it seems consequent to continue using i2c->flags >>>> for that purpose and not to introduce another method. If we don't need >>>> backward compatibility, we could drop the flags completely and just use >>>> callback functions. >>> I don't understand why you don't like it. It's an elegant solution >>> and it simplifies the code somewhat. After grabbing the callback >>> pointer the compatibility code can simply override it. But I won't >>> belabor the point or oppose the patch if you stick with the flags >>> pointer. >> I changed my mind ;-). Have a look to PATCH v2 I sent out a few minutes ago. > > I saw and I like. :-) > >>> I've been thinking about this more. These tables are only ever going >>> to be used by the i2c_mpc driver and so really they are a part of the >>> i2c_mpc driver itself. Putting them into common code doesn't make any >>> sense because it is not common code. I will not merge a patch that >>> puts them into mpc5200 common code. >> It's not common code, I agree. How about putting it into mpc52xx_i2c.c >> and use: >> >> $ cat Makefile >> obj-$(CONFIG_I2C_MPC) += mpc52xx_i2c.o >> >> Or it could be moved back to the i2c_mpc driver and we add stubs for the >> functions to get the bus frequency, or use #ifdef's. > > I'm happy with either as long as it lives in the same directory as the > i2c_mpc driver, and as long as the i2c maintainers are okay with it. Ben, any preference here? See also below. > Oh, and if you use a separate file it should be statically linked into > the i2c_mpc module using the i2c_mpc-$(CONFIG_WHATEVER) trick. No > EXPORT_SYMBOLS should be needed. Yep, then we would have in "drivers/i2c/busses/Makefile" obj-$(CONFIG_I2C_MPC) += i2c-mpc.o i2c-mpc-y = i2c-mpc.o i2c-mpc-$(CONFIG_FSL_SOC) += i2c-mpc-8xxx.o i2c-mpc-$(CONFIG_PPC_52xx) += i2c-mpc-52xx.o And a common include file i2c-mpc.h including the stubs for the arch dependent functions. But we may get in trouble when we need support for the MPC512x. I currently tend to add the FDR related code to an extra file i2c-mpc-fdr.c, plus i2c-mpc.h and use the good old #ifdef's to select the relevant code. Wolfgang.
Index: linux-2.6/drivers/i2c/busses/i2c-mpc.c =================================================================== --- linux-2.6.orig/drivers/i2c/busses/i2c-mpc.c 2009-03-31 13:28:03.000000000 +0200 +++ linux-2.6/drivers/i2c/busses/i2c-mpc.c 2009-03-31 13:38:01.355720989 +0200 @@ -20,12 +20,14 @@ #include <linux/of_platform.h> #include <linux/of_i2c.h> -#include <asm/io.h> +#include <linux/io.h> #include <linux/fsl_devices.h> #include <linux/i2c.h> #include <linux/interrupt.h> #include <linux/delay.h> +#include <sysdev/fsl_soc.h> + #define DRV_NAME "mpc-i2c" #define MPC_I2C_FDR 0x04 @@ -50,6 +52,7 @@ #define CSR_RXAK 0x01 struct mpc_i2c { + struct device *dev; void __iomem *base; u32 interrupt; wait_queue_head_t queue; @@ -105,7 +108,7 @@ while (!(readb(i2c->base + MPC_I2C_SR) & CSR_MIF)) { schedule(); if (time_after(jiffies, orig_jiffies + timeout)) { - pr_debug("I2C: timeout\n"); + dev_dbg(i2c->dev, "timeout\n"); writeccr(i2c, 0); result = -EIO; break; @@ -119,10 +122,10 @@ (i2c->interrupt & CSR_MIF), timeout * HZ); if (unlikely(result < 0)) { - pr_debug("I2C: wait interrupted\n"); + dev_dbg(i2c->dev, "wait interrupted\n"); writeccr(i2c, 0); } else if (unlikely(!(i2c->interrupt & CSR_MIF))) { - pr_debug("I2C: wait timeout\n"); + dev_dbg(i2c->dev, "wait timeout\n"); writeccr(i2c, 0); result = -ETIMEDOUT; } @@ -135,17 +138,17 @@ return result; if (!(x & CSR_MCF)) { - pr_debug("I2C: unfinished\n"); + dev_dbg(i2c->dev, "unfinished\n"); return -EIO; } if (x & CSR_MAL) { - pr_debug("I2C: MAL\n"); + dev_dbg(i2c->dev, "MAL\n"); return -EIO; } if (writing && (x & CSR_RXAK)) { - pr_debug("I2C: No RXAK\n"); + dev_dbg(i2c->dev, "No RXAK\n"); /* generate stop */ writeccr(i2c, CCR_MEN); return -EIO; @@ -153,17 +156,38 @@ return 0; } -static void mpc_i2c_setclock(struct mpc_i2c *i2c) +static void mpc_i2c_setclock(struct device_node *node, + struct mpc_i2c *i2c, u32 clock) { - /* Set clock and filters */ - if (i2c->flags & FSL_I2C_DEV_SEPARATE_DFSRR) { - writeb(0x31, i2c->base + MPC_I2C_FDR); - writeb(0x10, i2c->base + MPC_I2C_DFSRR); - } else if (i2c->flags & FSL_I2C_DEV_CLOCK_5200) - writeb(0x3f, i2c->base + MPC_I2C_FDR); - else - writel(0x1031, i2c->base + MPC_I2C_FDR); -} + int fdr; + + fdr = fsl_i2c_get_fdr(node, clock, i2c->flags); + + if (i2c->flags & FSL_I2C_DEV_CLOCK_5200) { + pr_debug("I2C: old fdr=%d\n", readb(i2c->base + MPC_I2C_FDR)); + if (fdr < 0) + fdr = 0x3f; /* backward compatibility */ + writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR); + dev_info("clock %d Hz (fdr=%d)\n", clock, fdr); + } else { + if (fdr < 0) + fdr = 0x1031; /* backward compatibility */ + if (i2c->flags & FSL_I2C_DEV_SEPARATE_DFSRR) { + pr_debug("I2C: old dfsrr=%d fdr=%d\n", + readb(i2c->base + MPC_I2C_DFSRR), + readb(i2c->base + MPC_I2C_FDR)); + writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR); + writeb((fdr >> 8) & 0xff, i2c->base + MPC_I2C_DFSRR); + dev_info("clock %d Hz (dfsrr=%d fdr=%d)\n", + clock, fdr >> 8, fdr & 0xff); + } else { + pr_debug("I2C: old fdr=%d\n", + readl(i2c->base + MPC_I2C_FDR)); + writel(fdr & 0xffff, i2c->base + MPC_I2C_FDR); + dev_info("clock %d Hz (fdr=%d)\n", clock, fdr); + } + } + } static void mpc_i2c_start(struct mpc_i2c *i2c) { @@ -267,12 +291,12 @@ /* Allow bus up to 1s to become not busy */ while (readb(i2c->base + MPC_I2C_SR) & CSR_MBB) { if (signal_pending(current)) { - pr_debug("I2C: Interrupted\n"); + dev_dbg(i2c->dev, "interrupted\n"); writeccr(i2c, 0); return -EINTR; } if (time_after(jiffies, orig_jiffies + HZ)) { - pr_debug("I2C: timeout\n"); + dev_dbg(i2c->dev, "timeout\n"); if (readb(i2c->base + MPC_I2C_SR) == (CSR_MCF | CSR_MBB | CSR_RXAK)) mpc_i2c_fixup(i2c); @@ -283,9 +307,10 @@ for (i = 0; ret >= 0 && i < num; i++) { pmsg = &msgs[i]; - pr_debug("Doing %s %d bytes to 0x%02x - %d of %d messages\n", - pmsg->flags & I2C_M_RD ? "read" : "write", - pmsg->len, pmsg->addr, i + 1, num); + dev_dbg(i2c->dev, + "doing %s %d bytes to 0x%02x - %d of %d messages\n", + pmsg->flags & I2C_M_RD ? "read" : "write", + pmsg->len, pmsg->addr, i + 1, num); if (pmsg->flags & I2C_M_RD) ret = mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i); @@ -316,9 +341,12 @@ static int __devinit fsl_i2c_probe(struct of_device *op, const struct of_device_id *match) { - int result = 0; struct mpc_i2c *i2c; + const u32 *prop; + u32 clock = 0; int set_clock; + int result = 0; + int plen; i2c = kzalloc(sizeof(*i2c), GFP_KERNEL); if (!i2c) @@ -328,7 +356,11 @@ set_clock = 0; } else { set_clock = 1; + prop = of_get_property(op->node, "clock-frequency", &plen); + if (prop && plen == sizeof(u32)) + clock = *prop; + /* Backwards compatibility */ if (of_get_property(op->node, "dfsrr", NULL)) i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR; @@ -356,11 +388,15 @@ } } - if (set_clock) - mpc_i2c_setclock(i2c); + if (set_clock) { + if (match->data) + i2c->flags = (u32)match->data; + mpc_i2c_setclock(op->node, i2c, clock); + } dev_set_drvdata(&op->dev, i2c); + i2c->dev = &op->dev; i2c->adap = mpc_ops; i2c_set_adapdata(&i2c->adap, i2c); i2c->adap.dev.parent = &op->dev; @@ -402,9 +438,23 @@ }; static const struct of_device_id mpc_i2c_of_match[] = { - {.compatible = "fsl-i2c",}, + {.compatible = "fsl,mpc5200b-i2c", + .data = (void *)FSL_I2C_DEV_CLOCK_5200, }, + {.compatible = "fsl,mpc5200-i2c", + .data = (void *)FSL_I2C_DEV_CLOCK_5200, }, + {.compatible = "fsl,mpc8313-i2c", + .data = (void *)FSL_I2C_DEV_SEPARATE_DFSRR, }, + {.compatible = "fsl,mpc8543-i2c", + .data = (void *)(FSL_I2C_DEV_SEPARATE_DFSRR | + FSL_I2C_DEV_CLOCK_DIV2), }, + {.compatible = "fsl,mpc8544-i2c", + .data = (void *)(FSL_I2C_DEV_SEPARATE_DFSRR | + FSL_I2C_DEV_CLOCK_DIV23), }, + /* Backward compatibility */ + {.compatible = "fsl-i2c", }, {}, }; + MODULE_DEVICE_TABLE(of, mpc_i2c_of_match); @@ -425,7 +475,7 @@ rv = of_register_platform_driver(&mpc_i2c_driver); if (rv) - printk(KERN_ERR DRV_NAME + printk(KERN_ERR DRV_NAME " of_register_platform_driver failed (%i)\n", rv); return rv; } Index: linux-2.6/arch/powerpc/sysdev/fsl_soc.c =================================================================== --- linux-2.6.orig/arch/powerpc/sysdev/fsl_soc.c 2009-03-31 13:25:08.000000000 +0200 +++ linux-2.6/arch/powerpc/sysdev/fsl_soc.c 2009-03-31 13:34:40.531721011 +0200 @@ -102,6 +102,96 @@ } EXPORT_SYMBOL(fsl_get_sys_freq); +#ifdef CONFIG_I2C_MPC +static const struct fsl_i2c_divider { + u16 divider; + u16 fdr; /* including dfsrr */ +} fsl_i2c_8xxx_dividers[] = { + {160, 0x0120}, {192, 0x0121}, {224, 0x0122}, {256, 0x0123}, + {288, 0x0100}, {320, 0x0101}, {352, 0x0601}, {384, 0x0102}, + {416, 0x0602}, {448, 0x0126}, {480, 0x0103}, {512, 0x0127}, + {544, 0x0b03}, {576, 0x0104}, {608, 0x1603}, {640, 0x0105}, + {672, 0x2003}, {704, 0x0b05}, {736, 0x2b03}, {768, 0x0106}, + {800, 0x3603}, {832, 0x0b06}, {896, 0x012a}, {960, 0x0107}, + {1024, 0x012b}, {1088, 0x1607}, {1152, 0x0108}, {1216, 0x2b07}, + {1280, 0x0109}, {1408, 0x1609}, {1536, 0x010a}, {1664, 0x160a}, + {1792, 0x012e}, {1920, 0x010b}, {2048, 0x012f}, {2176, 0x2b0b}, + {2304, 0x010c}, {2560, 0x010d}, {2816, 0x2b0d}, {3072, 0x010e}, + {3328, 0x2b0e}, {3584, 0x0132}, {3840, 0x010f}, {4096, 0x0133}, + {4608, 0x0110}, {5120, 0x0111}, {6144, 0x0112}, {7168, 0x0136}, + {7680, 0x0113}, {8192, 0x0137}, {9216, 0x0114}, {10240, 0x0115}, + {12288, 0x0116}, {14336, 0x013a}, {15360, 0x0117}, {16384, 0x013b}, + {18432, 0x0118}, {20480, 0x0119}, {24576, 0x011a}, {28672, 0x013e}, + {30720, 0x011b}, {32768, 0x013f}, {36864, 0x011c}, {40960, 0x011d}, + {49152, 0x011e}, {61440, 0x011f} +}; + +u32 fsl_i2c_get_sec_cfg(void) +{ + struct device_node *node = NULL; + u32 __iomem *reg; + u32 val = 0; + + node = of_find_node_by_name(NULL, "global-utilities"); + if (node) { + const u32 *prop = of_get_property(node, "reg", NULL); + if (prop) { + /* + * Map and check POR Device Status Register 2 + * (PORDEVSR2) at 0xE0014 + */ + reg = ioremap(get_immrbase() + *prop + 0x14, 0x4); + if (!reg) + printk(KERN_ERR + "Error: couldn't map PORDEVSR2\n"); + else + val = in_be32(reg); + iounmap(reg); + } + } + if (node) + of_node_put(node); + + return val; +} + +int fsl_i2c_get_fdr(struct device_node *node, u32 i2c_clock, u32 i2c_flags) +{ + const struct fsl_i2c_divider *div = NULL; + u32 src_clock, divider; + int i; + + if (!i2c_clock) + return -EINVAL; + + /* Determine divider value */ + src_clock = fsl_get_sys_freq(); + divider = src_clock / i2c_clock; + if (i2c_flags & FSL_I2C_DEV_CLOCK_DIV2) + divider /= 2; + else if (i2c_flags & FSL_I2C_DEV_CLOCK_DIV3) + divider /= 3; + else if (i2c_flags & FSL_I2C_DEV_CLOCK_DIV23) + divider /= fsl_i2c_get_sec_cfg() ? 3 : 2; + + pr_debug("I2C: src_clock=%d clock=%d flags=%#x divider=%d\n", + src_clock, i2c_clock, i2c_flags, divider); + + /* + * We want to choose an FDR/DFSR that generates an I2C bus speed that + * is equal to or lower than the requested speed. + */ + for (i = 0; i < ARRAY_SIZE(fsl_i2c_8xxx_dividers); i++) { + div = &fsl_i2c_8xxx_dividers[i]; + if (div->divider >= divider) + break; + } + + return div ? (int)div->fdr : -EINVAL; +} +EXPORT_SYMBOL(fsl_i2c_get_fdr); +#endif /* CONFIG_I2C_MPC */ + #if defined(CONFIG_CPM2) || defined(CONFIG_QUICC_ENGINE) || defined(CONFIG_8xx) static u32 brgfreq = -1; Index: linux-2.6/include/linux/fsl_devices.h =================================================================== --- linux-2.6.orig/include/linux/fsl_devices.h 2009-03-31 13:25:08.000000000 +0200 +++ linux-2.6/include/linux/fsl_devices.h 2009-03-31 13:28:54.305720748 +0200 @@ -68,6 +68,12 @@ /* Flags related to I2C device features */ #define FSL_I2C_DEV_SEPARATE_DFSRR 0x00000001 #define FSL_I2C_DEV_CLOCK_5200 0x00000002 +#define FSL_I2C_DEV_CLOCK_DIV2 0x00000004 +#define FSL_I2C_DEV_CLOCK_DIV3 0x00000008 +#define FSL_I2C_DEV_CLOCK_DIV23 0x00000010 + +extern int fsl_i2c_get_fdr(struct device_node *node, + u32 i2c_clock, u32 i2c_flags); enum fsl_usb2_operating_modes { FSL_USB2_MPH_HOST, Index: linux-2.6/arch/powerpc/platforms/52xx/mpc52xx_common.c =================================================================== --- linux-2.6.orig/arch/powerpc/platforms/52xx/mpc52xx_common.c 2009-03-31 13:25:08.000000000 +0200 +++ linux-2.6/arch/powerpc/platforms/52xx/mpc52xx_common.c 2009-03-31 13:28:54.309718526 +0200 @@ -225,3 +225,51 @@ while (1); } + +/** + * fsl_i2c_get_fdr: get calculate and return I2 frequency divider register + */ +static const struct mpc52xx_i2c_divider { + u16 divider; + u16 fdr; /* including dfsrr */ +} mpc52xx_i2_dividers[] = { + {20, 0x20}, {22, 0x21}, {24, 0x22}, {26, 0x23}, + {28, 0x24}, {30, 0x01}, {32, 0x25}, {34, 0x02}, + {36, 0x26}, {40, 0x27}, {44, 0x04}, {48, 0x28}, + {56, 0x29}, {64, 0x2a}, {68, 0x07}, {72, 0x2b}, + {80, 0x2c}, {88, 0x09}, {96, 0x2d}, {104, 0x0a}, + {112, 0x2e}, {128, 0x2f}, {144, 0x0c}, {160, 0x30}, + {192, 0x31}, {224, 0x32}, {240, 0x0f}, {256, 0x33}, + {288, 0x10}, {320, 0x34}, {384, 0x35}, {448, 0x36}, + {480, 0x13}, {512, 0x37}, {576, 0x14}, {640, 0x38}, + {768, 0x39}, {896, 0x3a}, {960, 0x17}, {1024, 0x3b}, + {1152, 0x18}, {1280, 0x3c}, {1536, 0x3d}, {1792, 0x3e}, + {1920, 0x1b}, {2048, 0x3f}, {2304, 0x1c}, {2560, 0x1d}, + {3072, 0x1e}, {3840, 0x1f} +}; + +int fsl_i2c_get_fdr(struct device_node *node, u32 i2c_clock, u32 i2c_flags) +{ + const struct fsl_i2c_divider *div = NULL; + u32 divider; + int i; + + if (!i2c_clock) + return -EINVAL; + + /* Determine divider value */ + divider = mpc52xx_find_ipb_freq(node) / i2c_clock; + + /* + * We want to choose an FDR/DFSR that generates an I2C bus speed that + * is equal to or lower than the requested speed. + */ + for (i = 0; i < ARRAY_SIZE(fsl_i2c_8xxx_dividers); i++) { + div = &fsl_i2c_8xxx_dividers[i]; + if (div->divider >= divider) + break; + } + + return div ? (int)div->fdr : -EINVAL; +} +EXPORT_SYMBOL(fsl_i2c_get_fdr);
This patch makes the I2C bus speed configurable by using the I2C node property "clock-frequency". If the property is not defined, the old fixed clock settings will be used for backward comptibility. The generic I2C clock properties, especially the CPU-specific source clock pre-scaler are defined via the OF match table: static const struct of_device_id mpc_i2c_of_match[] = { {.compatible = "fsl,mpc5200b-i2c", .data = (void *)FSL_I2C_DEV_CLOCK_5200, }, {.compatible = "fsl,mpc5200-i2c", .data = (void *)FSL_I2C_DEV_CLOCK_5200, }, {.compatible = "fsl,mpc8313-i2c", .data = (void *)FSL_I2C_DEV_SEPARATE_DFSRR, }, {.compatible = "fsl,mpc8543-i2c", .data = (void *)(FSL_I2C_DEV_SEPARATE_DFSRR | FSL_I2C_DEV_CLOCK_DIV2), }, {.compatible = "fsl,mpc8544-i2c", .data = (void *)(FSL_I2C_DEV_SEPARATE_DFSRR | FSL_I2C_DEV_CLOCK_DIV23), }, /* Backward compatibility */ {.compatible = "fsl-i2c", }, {}, }; The "data" field defines the relevant I2C flags for the comptible CPU. It used arch-specific tables and functions to determine the proper Freqency Divider Register (fdr). Furthermore dev_dbg() and dev_info() are now used to profit from a more comprehensive output. Signed-off-by: Wolfgang Grandegger <wg@grandegger.com> --- arch/powerpc/platforms/52xx/mpc52xx_common.c | 48 ++++++++++++ arch/powerpc/sysdev/fsl_soc.c | 90 +++++++++++++++++++++++ drivers/i2c/busses/i2c-mpc.c | 104 +++++++++++++++++++-------- include/linux/fsl_devices.h | 6 + 4 files changed, 221 insertions(+), 27 deletions(-)