Re: [PATCH V3 1/4] drivers/i2c/busses/i2c-at91.c: remove broken driver

Felipe Balbi
2011-11-08T14:37:07Z

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Hi,

On Tue, Nov 08, 2011 at 11:49:24AM +0100, Nikolaus Voss wrote:
> Signed-off-by: Nikolaus Voss <n.voss@weinmann.de>
> ---
> drivers/i2c/busses/i2c-at91.c | 327 -----------------------------------------
> 1 files changed, 0 insertions(+), 327 deletions(-)
> delete mode 100644 drivers/i2c/busses/i2c-at91.c
>
> diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c
> deleted file mode 100644
> index 305c075..0000000
> --- a/drivers/i2c/busses/i2c-at91.c
> +++ /dev/null
> @@ -1,327 +0,0 @@
> -/*
> - i2c Support for Atmel's AT91 Two-Wire Interface (TWI)
> -
> - Copyright (C) 2004 Rick Bronson
> - Converted to 2.6 by Andrew Victor <andrew@sanpeople.com>
> -
> - Borrowed heavily from original work by:
> - Copyright (C) 2000 Philip Edelbrock <phil@stimpy.netroedge.com>
> -
> - 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.
> -*/
> -
> -#include <linux/module.h>
> -#include <linux/kernel.h>
> -#include <linux/err.h>
> -#include <linux/slab.h>
> -#include <linux/types.h>
> -#include <linux/delay.h>
> -#include <linux/i2c.h>
> -#include <linux/init.h>
> -#include <linux/clk.h>
> -#include <linux/platform_device.h>
> -#include <linux/io.h>
> -
> -#include <mach/at91_twi.h>
> -#include <mach/board.h>
> -#include <mach/cpu.h>
> -
> -#define TWI_CLOCK 100000 /* Hz. max 400 Kbits/sec */
> -
> -
> -static struct clk *twi_clk;
> -static void __iomem *twi_base;
> -
> -#define at91_twi_read(reg) __raw_readl(twi_base + (reg))
> -#define at91_twi_write(reg, val) __raw_writel((val), twi_base + (reg))
> -
> -
> -/*
> - * Initialize the TWI hardware registers.
> - */
> -static void __devinit at91_twi_hwinit(void)
> -{
> - unsigned long cdiv, ckdiv;
> -
> - at91_twi_write(AT91_TWI_IDR, 0xffffffff); /* Disable all interrupts */
> - at91_twi_write(AT91_TWI_CR, AT91_TWI_SWRST); /* Reset peripheral */
> - at91_twi_write(AT91_TWI_CR, AT91_TWI_MSEN); /* Set Master mode */
> -
> - /* Calcuate clock dividers */
> - cdiv = (clk_get_rate(twi_clk) / (2 * TWI_CLOCK)) - 3;
> - cdiv = cdiv + 1; /* round up */
> - ckdiv = 0;
> - while (cdiv > 255) {
> - ckdiv++;
> - cdiv = cdiv >> 1;
> - }
> -
> - if (cpu_is_at91rm9200()) { /* AT91RM9200 Errata #22 */
> - if (ckdiv > 5) {
> - printk(KERN_ERR "AT91 I2C: Invalid TWI_CLOCK value!\n");
> - ckdiv = 5;
> - }
> - }
> -
> - at91_twi_write(AT91_TWI_CWGR, (ckdiv << 16) | (cdiv << 8) | cdiv);
> -}
> -
> -/*
> - * Poll the i2c status register until the specified bit is set.
> - * Returns 0 if timed out (100 msec).
> - */
> -static short at91_poll_status(unsigned long bit)
> -{
> - int loop_cntr = 10000;
> -
> - do {
> - udelay(10);
> - } while (!(at91_twi_read(AT91_TWI_SR) & bit) && (--loop_cntr > 0));
> -
> - return (loop_cntr > 0);
> -}
> -
> -static int xfer_read(struct i2c_adapter *adap, unsigned char *buf, int length)
> -{
> - /* Send Start */
> - at91_twi_write(AT91_TWI_CR, AT91_TWI_START);
> -
> - /* Read data */
> - while (length--) {
> - if (!length) /* need to send Stop before reading last byte */
> - at91_twi_write(AT91_TWI_CR, AT91_TWI_STOP);
> - if (!at91_poll_status(AT91_TWI_RXRDY)) {
> - dev_dbg(&adap->dev, "RXRDY timeout\n");
> - return -ETIMEDOUT;
> - }
> - *buf++ = (at91_twi_read(AT91_TWI_RHR) & 0xff);
> - }
> -
> - return 0;
> -}
> -
> -static int xfer_write(struct i2c_adapter *adap, unsigned char *buf, int length)
> -{
> - /* Load first byte into transmitter */
> - at91_twi_write(AT91_TWI_THR, *buf++);
> -
> - /* Send Start */
> - at91_twi_write(AT91_TWI_CR, AT91_TWI_START);
> -
> - do {
> - if (!at91_poll_status(AT91_TWI_TXRDY)) {
> - dev_dbg(&adap->dev, "TXRDY timeout\n");
> - return -ETIMEDOUT;
> - }
> -
> - length--; /* byte was transmitted */
> -
> - if (length > 0) /* more data to send? */
> - at91_twi_write(AT91_TWI_THR, *buf++);
> - } while (length);
> -
> - /* Send Stop */
> - at91_twi_write(AT91_TWI_CR, AT91_TWI_STOP);
> -
> - return 0;
> -}
> -
> -/*
> - * Generic i2c master transfer entrypoint.
> - *
> - * Note: We do not use Atmel's feature of storing the "internal device address".
> - * Instead the "internal device address" has to be written using a separate
> - * i2c message.
> - * http://lists.arm.linux.org.uk/pipermail/linux-arm-kernel/2004-September/024411.html
> - */
> -static int at91_xfer(struct i2c_adapter *adap, struct i2c_msg *pmsg, int num)
> -{
> - int i, ret;
> -
> - dev_dbg(&adap->dev, "at91_xfer: processing %d messages:\n", num);
> -
> - for (i = 0; i < num; i++) {
> - dev_dbg(&adap->dev, " #%d: %sing %d byte%s %s 0x%02x\n", i,
> - pmsg->flags & I2C_M_RD ? "read" : "writ",
> - pmsg->len, pmsg->len > 1 ? "s" : "",
> - pmsg->flags & I2C_M_RD ? "from" : "to", pmsg->addr);
> -
> - at91_twi_write(AT91_TWI_MMR, (pmsg->addr << 16)
> - | ((pmsg->flags & I2C_M_RD) ? AT91_TWI_MREAD : 0));
> -
> - if (pmsg->len && pmsg->buf) { /* sanity check */
> - if (pmsg->flags & I2C_M_RD)
> - ret = xfer_read(adap, pmsg->buf, pmsg->len);
> - else
> - ret = xfer_write(adap, pmsg->buf, pmsg->len);
> -
> - if (ret)
> - return ret;
> -
> - /* Wait until transfer is finished */
> - if (!at91_poll_status(AT91_TWI_TXCOMP)) {
> - dev_dbg(&adap->dev, "TXCOMP timeout\n");
> - return -ETIMEDOUT;
> - }
> - }
> - dev_dbg(&adap->dev, "transfer complete\n");
> - pmsg++; /* next message */
> - }
> - return i;
> -}
> -
> -/*
> - * Return list of supported functionality.
> - */
> -static u32 at91_func(struct i2c_adapter *adapter)
> -{
> - return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
> -}
> -
> -static struct i2c_algorithm at91_algorithm = {
> - .master_xfer = at91_xfer,
> - .functionality = at91_func,
> -};
> -
> -/*
> - * Main initialization routine.
> - */
> -static int __devinit at91_i2c_probe(struct platform_device *pdev)
> -{
> - struct i2c_adapter *adapter;
> - struct resource *res;
> - int rc;
> -
> - res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> - if (!res)
> - return -ENXIO;
> -
> - if (!request_mem_region(res->start, resource_size(res), "at91_i2c"))
> - return -EBUSY;
> -
> - twi_base = ioremap(res->start, resource_size(res));
> - if (!twi_base) {
> - rc = -ENOMEM;
> - goto fail0;
> - }
> -
> - twi_clk = clk_get(NULL, "twi_clk");
> - if (IS_ERR(twi_clk)) {
> - dev_err(&pdev->dev, "no clock defined\n");
> - rc = -ENODEV;
> - goto fail1;
> - }
> -
> - adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL);
> - if (adapter == NULL) {
> - dev_err(&pdev->dev, "can't allocate inteface!\n");
> - rc = -ENOMEM;
> - goto fail2;
> - }
> - snprintf(adapter->name, sizeof(adapter->name), "AT91");
> - adapter->algo = &at91_algorithm;
> - adapter->class = I2C_CLASS_HWMON;
> - adapter->dev.parent = &pdev->dev;
> - /* adapter->id == 0 ... only one TWI controller for now */
> -
> - platform_set_drvdata(pdev, adapter);
> -
> - clk_enable(twi_clk); /* enable peripheral clock */
> - at91_twi_hwinit(); /* initialize TWI controller */
> -
> - rc = i2c_add_numbered_adapter(adapter);
> - if (rc) {
> - dev_err(&pdev->dev, "Adapter %s registration failed\n",
> - adapter->name);
> - goto fail3;
> - }
> -
> - dev_info(&pdev->dev, "AT91 i2c bus driver.\n");
> - return 0;
> -
> -fail3:
> - platform_set_drvdata(pdev, NULL);
> - kfree(adapter);
> - clk_disable(twi_clk);
> -fail2:
> - clk_put(twi_clk);
> -fail1:
> - iounmap(twi_base);
> -fail0:
> - release_mem_region(res->start, resource_size(res));
> -
> - return rc;
> -}
> -
> -static int __devexit at91_i2c_remove(struct platform_device *pdev)
> -{
> - struct i2c_adapter *adapter = platform_get_drvdata(pdev);
> - struct resource *res;
> - int rc;
> -
> - rc = i2c_del_adapter(adapter);
> - platform_set_drvdata(pdev, NULL);
> -
> - res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> - iounmap(twi_base);
> - release_mem_region(res->start, resource_size(res));
> -
> - clk_disable(twi_clk); /* disable peripheral clock */
> - clk_put(twi_clk);
> -
> - return rc;
> -}
> -
> -#ifdef CONFIG_PM
> -
> -/* NOTE: could save a few mA by keeping clock off outside of at91_xfer... */
> -
> -static int at91_i2c_suspend(struct platform_device *pdev, pm_message_t mesg)
> -{
> - clk_disable(twi_clk);
> - return 0;
> -}
> -
> -static int at91_i2c_resume(struct platform_device *pdev)
> -{
> - return clk_enable(twi_clk);
> -}
> -
> -#else
> -#define at91_i2c_suspend NULL
> -#define at91_i2c_resume NULL
> -#endif
> -
> -/* work with "modprobe at91_i2c" from hotplugging or coldplugging */
> -MODULE_ALIAS("platform:at91_i2c");
> -
> -static struct platform_driver at91_i2c_driver = {
> - .probe = at91_i2c_probe,
> - .remove = __devexit_p(at91_i2c_remove),
> - .suspend = at91_i2c_suspend,
> - .resume = at91_i2c_resume,
> - .driver = {
> - .name = "at91_i2c",
> - .owner = THIS_MODULE,
> - },
> -};
> -
> -static int __init at91_i2c_init(void)
> -{
> - return platform_driver_register(&at91_i2c_driver);
> -}
> -
> -static void __exit at91_i2c_exit(void)
> -{
> - platform_driver_unregister(&at91_i2c_driver);
> -}
> -
> -module_init(at91_i2c_init);
> -module_exit(at91_i2c_exit);
> -
> -MODULE_AUTHOR("Rick Bronson");
> -MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91");
> -MODULE_LICENSE("GPL");

after this patch you could be breaking tree compilation.

--
balbi

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