i2c: Add platform driver on top of the new pca-algorithm
Wolfram Sang [Tue, 22 Apr 2008 20:16:46 +0000 (22:16 +0200)]
Tested on a blackfin.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

drivers/i2c/busses/Kconfig
drivers/i2c/busses/Makefile
drivers/i2c/busses/i2c-pca-platform.c [new file with mode: 0644]
include/linux/i2c-pca-platform.h [new file with mode: 0644]

index b04c995..51de2cc 100644 (file)
@@ -632,8 +632,8 @@ config I2C_PCA_ISA
        select I2C_ALGOPCA
        default n
        help
-         This driver supports ISA boards using the Philips PCA 9564
-         Parallel bus to I2C bus controller
+         This driver supports ISA boards using the Philips PCA9564
+         parallel bus to I2C bus controller.
          
          This driver can also be built as a module.  If so, the module
          will be called i2c-pca-isa.
@@ -643,6 +643,17 @@ config I2C_PCA_ISA
          delays when I2C/SMBus chip drivers are loaded (e.g. at boot
          time).  If unsure, say N.
 
+config I2C_PCA_PLATFORM
+       tristate "PCA9564 as platform device"
+       select I2C_ALGOPCA
+       default n
+       help
+         This driver supports a memory mapped Philips PCA9564
+         parallel bus to I2C bus controller.
+
+         This driver can also be built as a module.  If so, the module
+         will be called i2c-pca-platform.
+
 config I2C_MV64XXX
        tristate "Marvell mv64xxx I2C Controller"
        depends on (MV64X60 || PLAT_ORION) && EXPERIMENTAL
index ea7068f..378d5c0 100644 (file)
@@ -30,6 +30,7 @@ obj-$(CONFIG_I2C_PARPORT)     += i2c-parport.o
 obj-$(CONFIG_I2C_PARPORT_LIGHT)        += i2c-parport-light.o
 obj-$(CONFIG_I2C_PASEMI)       += i2c-pasemi.o
 obj-$(CONFIG_I2C_PCA_ISA)      += i2c-pca-isa.o
+obj-$(CONFIG_I2C_PCA_PLATFORM) += i2c-pca-platform.o
 obj-$(CONFIG_I2C_PIIX4)                += i2c-piix4.o
 obj-$(CONFIG_I2C_PMCMSP)       += i2c-pmcmsp.o
 obj-$(CONFIG_I2C_PNX)          += i2c-pnx.o
diff --git a/drivers/i2c/busses/i2c-pca-platform.c b/drivers/i2c/busses/i2c-pca-platform.c
new file mode 100644 (file)
index 0000000..9d75f51
--- /dev/null
@@ -0,0 +1,298 @@
+/*
+ *  i2c_pca_platform.c
+ *
+ *  Platform driver for the PCA9564 I2C controller.
+ *
+ *  Copyright (C) 2008 Pengutronix
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/i2c-algo-pca.h>
+#include <linux/i2c-pca-platform.h>
+#include <linux/gpio.h>
+
+#include <asm/irq.h>
+#include <asm/io.h>
+
+#define res_len(r)             ((r)->end - (r)->start + 1)
+
+struct i2c_pca_pf_data {
+       void __iomem                    *reg_base;
+       int                             irq;    /* if 0, use polling */
+       int                             gpio;
+       wait_queue_head_t               wait;
+       struct i2c_adapter              adap;
+       struct i2c_algo_pca_data        algo_data;
+       unsigned long                   io_base;
+       unsigned long                   io_size;
+};
+
+/* Read/Write functions for different register alignments */
+
+static int i2c_pca_pf_readbyte8(void *pd, int reg)
+{
+       struct i2c_pca_pf_data *i2c = pd;
+       return ioread8(i2c->reg_base + reg);
+}
+
+static int i2c_pca_pf_readbyte16(void *pd, int reg)
+{
+       struct i2c_pca_pf_data *i2c = pd;
+       return ioread8(i2c->reg_base + reg * 2);
+}
+
+static int i2c_pca_pf_readbyte32(void *pd, int reg)
+{
+       struct i2c_pca_pf_data *i2c = pd;
+       return ioread8(i2c->reg_base + reg * 4);
+}
+
+static void i2c_pca_pf_writebyte8(void *pd, int reg, int val)
+{
+       struct i2c_pca_pf_data *i2c = pd;
+       iowrite8(val, i2c->reg_base + reg);
+}
+
+static void i2c_pca_pf_writebyte16(void *pd, int reg, int val)
+{
+       struct i2c_pca_pf_data *i2c = pd;
+       iowrite8(val, i2c->reg_base + reg * 2);
+}
+
+static void i2c_pca_pf_writebyte32(void *pd, int reg, int val)
+{
+       struct i2c_pca_pf_data *i2c = pd;
+       iowrite8(val, i2c->reg_base + reg * 4);
+}
+
+
+static int i2c_pca_pf_waitforcompletion(void *pd)
+{
+       struct i2c_pca_pf_data *i2c = pd;
+       int ret = 0;
+
+       if (i2c->irq) {
+               ret = wait_event_interruptible(i2c->wait,
+                       i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
+                       & I2C_PCA_CON_SI);
+       } else {
+               /*
+                * Do polling...
+                * XXX: Could get stuck in extreme cases!
+                *      Maybe add timeout, but using irqs is preferred anyhow.
+                */
+               while ((i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
+                               & I2C_PCA_CON_SI) == 0)
+                       udelay(100);
+       }
+
+       return ret;
+}
+
+static void i2c_pca_pf_dummyreset(void *pd)
+{
+       struct i2c_pca_pf_data *i2c = pd;
+       printk(KERN_WARNING "%s: No reset-pin found. Chip may get stuck!\n",
+               i2c->adap.name);
+}
+
+static void i2c_pca_pf_resetchip(void *pd)
+{
+       struct i2c_pca_pf_data *i2c = pd;
+
+       gpio_set_value(i2c->gpio, 0);
+       ndelay(100);
+       gpio_set_value(i2c->gpio, 1);
+}
+
+static irqreturn_t i2c_pca_pf_handler(int this_irq, void *dev_id)
+{
+       struct i2c_pca_pf_data *i2c = dev_id;
+
+       if ((i2c->algo_data.read_byte(i2c, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0)
+               return IRQ_NONE;
+
+       wake_up_interruptible(&i2c->wait);
+
+       return IRQ_HANDLED;
+}
+
+
+static int __devinit i2c_pca_pf_probe(struct platform_device *pdev)
+{
+       struct i2c_pca_pf_data *i2c;
+       struct resource *res;
+       struct i2c_pca9564_pf_platform_data *platform_data =
+                               pdev->dev.platform_data;
+       int ret = 0;
+       int irq;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       irq = platform_get_irq(pdev, 0);
+       /* If irq is 0, we do polling. */
+
+       if (res == NULL) {
+               ret = -ENODEV;
+               goto e_print;
+       }
+
+       if (!request_mem_region(res->start, res_len(res), res->name)) {
+               ret = -ENOMEM;
+               goto e_print;
+       }
+
+       i2c = kzalloc(sizeof(struct i2c_pca_pf_data), GFP_KERNEL);
+       if (!i2c) {
+               ret = -ENOMEM;
+               goto e_alloc;
+       }
+
+       init_waitqueue_head(&i2c->wait);
+
+       i2c->reg_base = ioremap(res->start, res_len(res));
+       if (!i2c->reg_base) {
+               ret = -EIO;
+               goto e_remap;
+       }
+       i2c->io_base = res->start;
+       i2c->io_size = res_len(res);
+       i2c->irq = irq;
+
+       i2c->adap.nr = pdev->id >= 0 ? pdev->id : 0;
+       i2c->adap.owner = THIS_MODULE;
+       snprintf(i2c->adap.name, sizeof(i2c->adap.name), "PCA9564 at 0x%08lx",
+               (unsigned long) res->start);
+       i2c->adap.algo_data = &i2c->algo_data;
+       i2c->adap.dev.parent = &pdev->dev;
+       i2c->adap.timeout = platform_data->timeout;
+
+       i2c->algo_data.i2c_clock = platform_data->i2c_clock_speed;
+       i2c->algo_data.data = i2c;
+
+       switch (res->flags & IORESOURCE_MEM_TYPE_MASK) {
+       case IORESOURCE_MEM_32BIT:
+               i2c->algo_data.write_byte = i2c_pca_pf_writebyte32;
+               i2c->algo_data.read_byte = i2c_pca_pf_readbyte32;
+               break;
+       case IORESOURCE_MEM_16BIT:
+               i2c->algo_data.write_byte = i2c_pca_pf_writebyte16;
+               i2c->algo_data.read_byte = i2c_pca_pf_readbyte16;
+               break;
+       case IORESOURCE_MEM_8BIT:
+       default:
+               i2c->algo_data.write_byte = i2c_pca_pf_writebyte8;
+               i2c->algo_data.read_byte = i2c_pca_pf_readbyte8;
+               break;
+       }
+
+       i2c->algo_data.wait_for_completion = i2c_pca_pf_waitforcompletion;
+
+       i2c->gpio = platform_data->gpio;
+       i2c->algo_data.reset_chip = i2c_pca_pf_dummyreset;
+
+       /* Use gpio_is_valid() when in mainline */
+       if (i2c->gpio > -1) {
+               ret = gpio_request(i2c->gpio, i2c->adap.name);
+               if (ret == 0) {
+                       gpio_direction_output(i2c->gpio, 1);
+                       i2c->algo_data.reset_chip = i2c_pca_pf_resetchip;
+               } else {
+                       printk(KERN_WARNING "%s: Registering gpio failed!\n",
+                               i2c->adap.name);
+                       i2c->gpio = ret;
+               }
+       }
+
+       if (irq) {
+               ret = request_irq(irq, i2c_pca_pf_handler,
+                       IRQF_TRIGGER_FALLING, i2c->adap.name, i2c);
+               if (ret)
+                       goto e_reqirq;
+       }
+
+       if (i2c_pca_add_numbered_bus(&i2c->adap) < 0) {
+               ret = -ENODEV;
+               goto e_adapt;
+       }
+
+       platform_set_drvdata(pdev, i2c);
+
+       printk(KERN_INFO "%s registered.\n", i2c->adap.name);
+
+       return 0;
+
+e_adapt:
+       if (irq)
+               free_irq(irq, i2c);
+e_reqirq:
+       if (i2c->gpio > -1)
+               gpio_free(i2c->gpio);
+
+       iounmap(i2c->reg_base);
+e_remap:
+       kfree(i2c);
+e_alloc:
+       release_mem_region(res->start, res_len(res));
+e_print:
+       printk(KERN_ERR "Registering PCA9564 FAILED! (%d)\n", ret);
+       return ret;
+}
+
+static int __devexit i2c_pca_pf_remove(struct platform_device *pdev)
+{
+       struct i2c_pca_pf_data *i2c = platform_get_drvdata(pdev);
+       platform_set_drvdata(pdev, NULL);
+
+       i2c_del_adapter(&i2c->adap);
+
+       if (i2c->irq)
+               free_irq(i2c->irq, i2c);
+
+       if (i2c->gpio > -1)
+               gpio_free(i2c->gpio);
+
+       iounmap(i2c->reg_base);
+       release_mem_region(i2c->io_base, i2c->io_size);
+       kfree(i2c);
+
+       return 0;
+}
+
+static struct platform_driver i2c_pca_pf_driver = {
+       .probe = i2c_pca_pf_probe,
+       .remove = __devexit_p(i2c_pca_pf_remove),
+       .driver = {
+               .name = "i2c-pca-platform",
+               .owner = THIS_MODULE,
+       },
+};
+
+static int __init i2c_pca_pf_init(void)
+{
+       return platform_driver_register(&i2c_pca_pf_driver);
+}
+
+static void __exit i2c_pca_pf_exit(void)
+{
+       platform_driver_unregister(&i2c_pca_pf_driver);
+}
+
+MODULE_AUTHOR("Wolfram Sang <w.sang@pengutronix.de>");
+MODULE_DESCRIPTION("I2C-PCA9564 platform driver");
+MODULE_LICENSE("GPL");
+
+module_init(i2c_pca_pf_init);
+module_exit(i2c_pca_pf_exit);
+
diff --git a/include/linux/i2c-pca-platform.h b/include/linux/i2c-pca-platform.h
new file mode 100644 (file)
index 0000000..3d19187
--- /dev/null
@@ -0,0 +1,12 @@
+#ifndef I2C_PCA9564_PLATFORM_H
+#define I2C_PCA9564_PLATFORM_H
+
+struct i2c_pca9564_pf_platform_data {
+       int gpio;               /* pin to reset chip. driver will work when
+                                * not supplied (negative value), but it
+                                * cannot exit some error conditions then */
+       int i2c_clock_speed;    /* values are defined in linux/i2c-algo-pca.h */
+       int timeout;            /* timeout = this value * 10us */
+};
+
+#endif /* I2C_PCA9564_PLATFORM_H */