[PATCH 2.6] Hydra i2c
Geert Uytterhoeven
geert at linux-m68k.org
Sun Jan 25 22:22:02 EST 2004
On Sun, 18 Jan 2004, Christoph Hellwig wrote:
> On Sun, Jan 18, 2004 at 01:28:22PM +0100, Geert Uytterhoeven wrote:
> > +static int __devinit hydra_probe(struct pci_dev *dev,
> > + const struct pci_device_id *id)
> > +{
> > + unsigned int base_addr;
> > +
> > + base_addr = dev->resource[0].start;
>
> I think you should use pci_resource_start here.
>
> > + hydra_bit_data.data = ioremap(base_addr, 0x100);
>
> And pci_resource len instead of hardcoding it? Also you need to
> check the ioremap return value.
>
> You should also add a safety exit for the case the probe callback is
> called more than once. Or dynamic allocate a per-device struct instead
> of using hydra_bit_data.
>
> > +static void __exit i2c_hydra_exit(void)
> > +{
> > + pci_unregister_driver(&hydra_driver);
> > + iounmap(hydra_bit_data.data);
>
> The ioremap should move into the hydra_remove.
Here's a new version, incorporating these comments, and making a few more
changes:
- Use struct definition in <asm/hydra.h> instead of #defined offset
- Remove flushes are register writes, they are no longer needed
- Use pci_resource_start() instead of dev->resource[].start
- ioremap() the whole resource instead of the first 256 bytes
- Check for errors returned by ioremap() and i2c_bit_add_bus()
- Add resource management
- Call iounmap() in hydra_remove() instead of in i2c_hydra_exit()
- Let I2C_HYDRA depend on I2C and select I2C_ALGOBIT instead of depending on
I2C_ALGOBIT
--- linux-ppc-2.6.0/drivers/i2c/busses/i2c-hydra.c.orig 2003-12-21 12:47:29.000000000 +0100
+++ linux-ppc-2.6.0/drivers/i2c/busses/i2c-hydra.c 2004-01-25 11:30:13.000000000 +0100
@@ -0,0 +1,186 @@
+/*
+ i2c-hydra.c - Part of lm_sensors, Linux kernel modules
+ for hardware monitoring
+
+ i2c Support for the Apple `Hydra' Mac I/O
+
+ Copyright (c) 1999-2004 Geert Uytterhoeven <geert at linux-m68k.org>
+
+ Based on i2c Support for Via Technologies 82C586B South Bridge
+ Copyright (c) 1998, 1999 Kyösti Mälkki <kmalkki at cc.hut.fi>
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/types.h>
+#include <linux/i2c.h>
+#include <linux/i2c-algo-bit.h>
+#include <linux/init.h>
+#include <asm/io.h>
+#include <asm/hydra.h>
+
+
+#define HYDRA_CPD_PD0 0x00000001 /* CachePD lines */
+#define HYDRA_CPD_PD1 0x00000002
+#define HYDRA_CPD_PD2 0x00000004
+#define HYDRA_CPD_PD3 0x00000008
+
+#define HYDRA_SCLK HYDRA_CPD_PD0
+#define HYDRA_SDAT HYDRA_CPD_PD1
+#define HYDRA_SCLK_OE 0x00000010
+#define HYDRA_SDAT_OE 0x00000020
+
+static inline void pdregw(void *data, u32 val)
+{
+ struct Hydra *hydra = (struct Hydra *)data;
+ writel(val, &hydra->CachePD);
+}
+
+static inline u32 pdregr(void *data)
+{
+ struct Hydra *hydra = (struct Hydra *)data;
+ return readl(&hydra->CachePD);
+}
+
+static void hydra_bit_setscl(void *data, int state)
+{
+ u32 val = pdregr(data);
+ if (state)
+ val &= ~HYDRA_SCLK_OE;
+ else {
+ val &= ~HYDRA_SCLK;
+ val |= HYDRA_SCLK_OE;
+ }
+ pdregw(data, val);
+}
+
+static void hydra_bit_setsda(void *data, int state)
+{
+ u32 val = pdregr(data);
+ if (state)
+ val &= ~HYDRA_SDAT_OE;
+ else {
+ val &= ~HYDRA_SDAT;
+ val |= HYDRA_SDAT_OE;
+ }
+ pdregw(data, val);
+}
+
+static int hydra_bit_getscl(void *data)
+{
+ return (pdregr(data) & HYDRA_SCLK) != 0;
+}
+
+static int hydra_bit_getsda(void *data)
+{
+ return (pdregr(data) & HYDRA_SDAT) != 0;
+}
+
+/* ------------------------------------------------------------------------ */
+
+static struct i2c_algo_bit_data hydra_bit_data = {
+ .setsda = hydra_bit_setsda,
+ .setscl = hydra_bit_setscl,
+ .getsda = hydra_bit_getsda,
+ .getscl = hydra_bit_getscl,
+ .udelay = 5,
+ .mdelay = 5,
+ .timeout = HZ
+};
+
+static struct i2c_adapter hydra_adap = {
+ .owner = THIS_MODULE,
+ .name = "Hydra i2c",
+ .id = I2C_HW_B_HYDRA,
+ .algo_data = &hydra_bit_data,
+};
+
+static struct pci_device_id hydra_ids[] = {
+ {
+ .vendor = PCI_VENDOR_ID_APPLE,
+ .device = PCI_DEVICE_ID_APPLE_HYDRA,
+ .subvendor = PCI_ANY_ID,
+ .subdevice = PCI_ANY_ID,
+ },
+ { 0, }
+};
+
+static int __devinit hydra_probe(struct pci_dev *dev,
+ const struct pci_device_id *id)
+{
+ unsigned long base = pci_resource_start(dev, 0);
+ int res;
+
+ if (!request_mem_region(base+offsetof(struct Hydra, CachePD), 4,
+ hydra_adap.name))
+ return -EBUSY;
+
+ hydra_bit_data.data = ioremap(base, pci_resource_len(dev, 0));
+ if (hydra_bit_data.data == NULL) {
+ release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
+ return -ENODEV;
+ }
+
+ pdregw(hydra_bit_data.data, 0); /* clear SCLK_OE and SDAT_OE */
+ hydra_adap.dev.parent = &dev->dev;
+ res = i2c_bit_add_bus(&hydra_adap);
+ if (res < 0) {
+ iounmap(hydra_bit_data.data);
+ release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
+ return res;
+ }
+ return 0;
+}
+
+static void __devexit hydra_remove(struct pci_dev *dev)
+{
+ pdregw(hydra_bit_data.data, 0); /* clear SCLK_OE and SDAT_OE */
+ i2c_bit_del_bus(&hydra_adap);
+ iounmap(hydra_bit_data.data);
+ release_mem_region(pci_resource_start(dev, 0)+
+ offsetof(struct Hydra, CachePD), 4);
+}
+
+
+static struct pci_driver hydra_driver = {
+ .name = "hydra smbus",
+ .id_table = hydra_ids,
+ .probe = hydra_probe,
+ .remove = __devexit_p(hydra_remove),
+};
+
+static int __init i2c_hydra_init(void)
+{
+ return pci_module_init(&hydra_driver);
+}
+
+
+static void __exit i2c_hydra_exit(void)
+{
+ pci_unregister_driver(&hydra_driver);
+}
+
+
+
+MODULE_AUTHOR("Geert Uytterhoeven <geert at linux-m68k.org>");
+MODULE_DESCRIPTION("i2c for Apple Hydra Mac I/O");
+MODULE_LICENSE("GPL");
+
+module_init(i2c_hydra_init);
+module_exit(i2c_hydra_exit);
+
--- linux-ppc-2.6.0/drivers/i2c/busses/Makefile.orig 2003-12-18 10:18:52.000000000 +0100
+++ linux-ppc-2.6.0/drivers/i2c/busses/Makefile 2004-01-18 12:31:40.000000000 +0100
@@ -8,6 +8,7 @@
obj-$(CONFIG_I2C_AMD8111) += i2c-amd8111.o
obj-$(CONFIG_I2C_ELEKTOR) += i2c-elektor.o
obj-$(CONFIG_I2C_ELV) += i2c-elv.o
+obj-$(CONFIG_I2C_HYDRA) += i2c-hydra.o
obj-$(CONFIG_I2C_I801) += i2c-i801.o
obj-$(CONFIG_I2C_I810) += i2c-i810.o
obj-$(CONFIG_I2C_IBM_IIC) += i2c-ibm_iic.o
--- linux-ppc-2.6.0/drivers/i2c/busses/Kconfig.orig 2003-12-18 10:21:05.000000000 +0100
+++ linux-ppc-2.6.0/drivers/i2c/busses/Kconfig 2004-01-25 11:13:14.000000000 +0100
@@ -66,6 +66,18 @@
This support is also available as a module. If so, the module
will be called i2c-elv.
+config I2C_HYDRA
+ tristate "CHRP Apple Hydra Mac I/O I2C interface"
+ depends on I2C && PCI && PPC_CHRP && EXPERIMENTAL
+ select I2C_ALGOBIT
+ help
+ This supports the use of the I2C interface in the Apple Hydra Mac
+ I/O chip on some CHRP machines (e.g. the LongTrail). Say Y if you
+ have such a machine.
+
+ This support is also available as a module. If so, the module
+ will be called i2c-hydra.
+
config I2C_I801
tristate "Intel 801"
depends on I2C && PCI && EXPERIMENTAL
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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