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author | Nikolaus Voss <n.voss@weinmann.de> | 2011-11-08 11:49:24 +0100 |
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committer | Wolfram Sang <w.sang@pengutronix.de> | 2012-09-12 14:49:12 +0200 |
commit | a879e9c34b93ee43f5caa7f94eb17e7af4f6ef50 (patch) | |
tree | bef8ff00920554f7930ef47bcfebbab4f03d3c01 /drivers/i2c/busses/i2c-at91.c | |
parent | af2a5f09fb6d317a0ec4b5026cd50f0b49a60419 (diff) | |
download | op-kernel-dev-a879e9c34b93ee43f5caa7f94eb17e7af4f6ef50.zip op-kernel-dev-a879e9c34b93ee43f5caa7f94eb17e7af4f6ef50.tar.gz |
i2c: at91: remove old polling driver
It will get replaced by a superior one. Safe to remove since this one
depends on BROKEN anyhow.
Signed-off-by: Nikolaus Voss <n.voss@weinmann.de>
Tested-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Reviewed-by: Nicolas Ferre <nicolas.ferre@atmel.com>
[wsa: added commit message]
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Diffstat (limited to 'drivers/i2c/busses/i2c-at91.c')
-rw-r--r-- | drivers/i2c/busses/i2c-at91.c | 315 |
1 files changed, 0 insertions, 315 deletions
diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c deleted file mode 100644 index e24484b..0000000 --- a/drivers/i2c/busses/i2c-at91.c +++ /dev/null @@ -1,315 +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 device *dev) -{ - clk_disable(twi_clk); - return 0; -} - -static int at91_i2c_resume(struct device *dev) -{ - return clk_enable(twi_clk); -} - -static SIMPLE_DEV_PM_OPS(at91_i2c_pm, at91_i2c_suspend, at91_i2c_resume); -#define AT91_I2C_PM (&at91_i2c_pm) - -#else -#define AT91_I2C_PM NULL -#endif - -static struct platform_driver at91_i2c_driver = { - .probe = at91_i2c_probe, - .remove = __devexit_p(at91_i2c_remove), - .driver = { - .name = "at91_i2c", - .owner = THIS_MODULE, - .pm = AT91_I2C_PM, - }, -}; - -module_platform_driver(at91_i2c_driver); - -MODULE_AUTHOR("Rick Bronson"); -MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91"); -MODULE_LICENSE("GPL"); -MODULE_ALIAS("platform:at91_i2c"); |