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	i2c: New PMC MSP71xx TWI bus driver
Add TWI driver for the PMC-Sierra MSP71xx devices. [JD: Drop the probe hack, don't set algo_data as we never use it, return the right error code if the driver registration fails.] Signed-off-by: Marc St-Jean <Marc_St-Jean@pmc-sierra.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
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					 3 changed files with 663 additions and 0 deletions
				
			
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			@ -652,4 +652,13 @@ config I2C_PNX
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	  This driver can also be built as a module.  If so, the module
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	  will be called i2c-pnx.
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config I2C_PMCMSP
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	tristate "PMC MSP I2C TWI Controller"
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	depends on PMC_MSP
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	help
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	  This driver supports the PMC TWI controller on MSP devices.
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	  This driver can also be built as module. If so, the module
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	  will be called i2c-pmcmsp.
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endmenu
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			@ -32,6 +32,7 @@ obj-$(CONFIG_I2C_PARPORT_LIGHT)	+= i2c-parport-light.o
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obj-$(CONFIG_I2C_PASEMI)	+= i2c-pasemi.o
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obj-$(CONFIG_I2C_PCA_ISA)	+= i2c-pca-isa.o
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obj-$(CONFIG_I2C_PIIX4)		+= i2c-piix4.o
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obj-$(CONFIG_I2C_PMCMSP)	+= i2c-pmcmsp.o
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obj-$(CONFIG_I2C_PNX)		+= i2c-pnx.o
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obj-$(CONFIG_I2C_PROSAVAGE)	+= i2c-prosavage.o
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obj-$(CONFIG_I2C_PXA)		+= i2c-pxa.o
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										653
									
								
								drivers/i2c/busses/i2c-pmcmsp.c
									
									
									
									
									
										Normal file
									
								
							
							
						
						
									
										653
									
								
								drivers/i2c/busses/i2c-pmcmsp.c
									
									
									
									
									
										Normal file
									
								
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			@ -0,0 +1,653 @@
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/*
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 * Specific bus support for PMC-TWI compliant implementation on MSP71xx.
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 *
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 * Copyright 2005-2007 PMC-Sierra, Inc.
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 *
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 *  This program is free software; you can redistribute  it and/or modify it
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 *  under  the terms of  the GNU General  Public License as published by the
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 *  Free Software Foundation;  either version 2 of the  License, or (at your
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 *  option) any later version.
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 *
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 *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
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 *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
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 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
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 *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
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 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
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 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
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 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
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 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 *
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 *  You should have received a copy of the  GNU General Public License along
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 *  with this program; if not, write  to the Free Software Foundation, Inc.,
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 *  675 Mass Ave, Cambridge, MA 02139, USA.
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 */
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/i2c.h>
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#include <linux/interrupt.h>
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#include <linux/completion.h>
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#include <linux/mutex.h>
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#include <linux/delay.h>
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#include <asm/io.h>
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#define DRV_NAME	"pmcmsptwi"
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#define MSP_TWI_SF_CLK_REG_OFFSET	0x00
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#define MSP_TWI_HS_CLK_REG_OFFSET	0x04
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#define MSP_TWI_CFG_REG_OFFSET		0x08
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#define MSP_TWI_CMD_REG_OFFSET		0x0c
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#define MSP_TWI_ADD_REG_OFFSET		0x10
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#define MSP_TWI_DAT_0_REG_OFFSET	0x14
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#define MSP_TWI_DAT_1_REG_OFFSET	0x18
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#define MSP_TWI_INT_STS_REG_OFFSET	0x1c
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#define MSP_TWI_INT_MSK_REG_OFFSET	0x20
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#define MSP_TWI_BUSY_REG_OFFSET		0x24
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#define MSP_TWI_INT_STS_DONE			(1 << 0)
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#define MSP_TWI_INT_STS_LOST_ARBITRATION	(1 << 1)
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#define MSP_TWI_INT_STS_NO_RESPONSE		(1 << 2)
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#define MSP_TWI_INT_STS_DATA_COLLISION		(1 << 3)
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#define MSP_TWI_INT_STS_BUSY			(1 << 4)
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#define MSP_TWI_INT_STS_ALL			0x1f
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#define MSP_MAX_BYTES_PER_RW		8
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#define MSP_MAX_POLL			5
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#define MSP_POLL_DELAY			10
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#define MSP_IRQ_TIMEOUT			(MSP_MAX_POLL * MSP_POLL_DELAY)
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/* IO Operation macros */
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#define pmcmsptwi_readl		__raw_readl
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#define pmcmsptwi_writel	__raw_writel
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/* TWI command type */
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enum pmcmsptwi_cmd_type {
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	MSP_TWI_CMD_WRITE	= 0,	/* Write only */
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	MSP_TWI_CMD_READ	= 1,	/* Read only */
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	MSP_TWI_CMD_WRITE_READ	= 2,	/* Write then Read */
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};
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/* The possible results of the xferCmd */
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enum pmcmsptwi_xfer_result {
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	MSP_TWI_XFER_OK	= 0,
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	MSP_TWI_XFER_TIMEOUT,
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	MSP_TWI_XFER_BUSY,
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	MSP_TWI_XFER_DATA_COLLISION,
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	MSP_TWI_XFER_NO_RESPONSE,
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	MSP_TWI_XFER_LOST_ARBITRATION,
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};
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/* Corresponds to a PMCTWI clock configuration register */
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struct pmcmsptwi_clock {
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	u8 filter;	/* Bits 15:12,	default = 0x03 */
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	u16 clock;	/* Bits 9:0,	default = 0x001f */
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};
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struct pmcmsptwi_clockcfg {
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	struct pmcmsptwi_clock standard;  /* The standard/fast clock config */
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	struct pmcmsptwi_clock highspeed; /* The highspeed clock config */
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};
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/* Corresponds to the main TWI configuration register */
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struct pmcmsptwi_cfg {
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	u8 arbf;	/* Bits 15:12,	default=0x03 */
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	u8 nak;		/* Bits 11:8,	default=0x03 */
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	u8 add10;	/* Bit 7,	default=0x00 */
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	u8 mst_code;	/* Bits 6:4,	default=0x00 */
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	u8 arb;		/* Bit 1,	default=0x01 */
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	u8 highspeed;	/* Bit 0,	default=0x00 */
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};
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/* A single pmctwi command to issue */
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struct pmcmsptwi_cmd {
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	u16 addr;	/* The slave address (7 or 10 bits) */
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	enum pmcmsptwi_cmd_type type;	/* The command type */
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	u8 write_len;	/* Number of bytes in the write buffer */
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	u8 read_len;	/* Number of bytes in the read buffer */
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	u8 *write_data;	/* Buffer of characters to send */
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	u8 *read_data;	/* Buffer to fill with incoming data */
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};
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/* The private data */
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struct pmcmsptwi_data {
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	void __iomem *iobase;			/* iomapped base for IO */
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	int irq;				/* IRQ to use (0 disables) */
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	struct completion wait;			/* Completion for xfer */
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	struct mutex lock;			/* Used for threadsafeness */
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	enum pmcmsptwi_xfer_result last_result;	/* result of last xfer */
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};
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/* The default settings */
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const static struct pmcmsptwi_clockcfg pmcmsptwi_defclockcfg = {
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	.standard = {
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		.filter	= 0x3,
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		.clock	= 0x1f,
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	},
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	.highspeed = {
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		.filter	= 0x3,
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		.clock	= 0x1f,
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	},
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};
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const static struct pmcmsptwi_cfg pmcmsptwi_defcfg = {
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	.arbf		= 0x03,
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	.nak		= 0x03,
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	.add10		= 0x00,
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	.mst_code	= 0x00,
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	.arb		= 0x01,
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	.highspeed	= 0x00,
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};
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static struct pmcmsptwi_data pmcmsptwi_data;
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static struct i2c_adapter pmcmsptwi_adapter;
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/* inline helper functions */
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static inline u32 pmcmsptwi_clock_to_reg(
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			const struct pmcmsptwi_clock *clock)
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{
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	return ((clock->filter & 0xf) << 12) | (clock->clock & 0x03ff);
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}
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static inline void pmcmsptwi_reg_to_clock(
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			u32 reg, struct pmcmsptwi_clock *clock)
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{
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	clock->filter = (reg >> 12) & 0xf;
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	clock->clock = reg & 0x03ff;
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}
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static inline u32 pmcmsptwi_cfg_to_reg(const struct pmcmsptwi_cfg *cfg)
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{
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	return ((cfg->arbf & 0xf) << 12) |
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		((cfg->nak & 0xf) << 8) |
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		((cfg->add10 & 0x1) << 7) |
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		((cfg->mst_code & 0x7) << 4) |
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		((cfg->arb & 0x1) << 1) |
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		(cfg->highspeed & 0x1);
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}
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static inline void pmcmsptwi_reg_to_cfg(u32 reg, struct pmcmsptwi_cfg *cfg)
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{
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	cfg->arbf = (reg >> 12) & 0xf;
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	cfg->nak = (reg >> 8) & 0xf;
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	cfg->add10 = (reg >> 7) & 0x1;
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	cfg->mst_code = (reg >> 4) & 0x7;
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	cfg->arb = (reg >> 1) & 0x1;
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	cfg->highspeed = reg & 0x1;
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}
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/*
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 * Sets the current clock configuration
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 */
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static void pmcmsptwi_set_clock_config(const struct pmcmsptwi_clockcfg *cfg,
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					struct pmcmsptwi_data *data)
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{
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	mutex_lock(&data->lock);
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	pmcmsptwi_writel(pmcmsptwi_clock_to_reg(&cfg->standard),
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				data->iobase + MSP_TWI_SF_CLK_REG_OFFSET);
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	pmcmsptwi_writel(pmcmsptwi_clock_to_reg(&cfg->highspeed),
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				data->iobase + MSP_TWI_HS_CLK_REG_OFFSET);
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	mutex_unlock(&data->lock);
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}
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/*
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 * Gets the current TWI bus configuration
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 */
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static void pmcmsptwi_get_twi_config(struct pmcmsptwi_cfg *cfg,
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					struct pmcmsptwi_data *data)
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{
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	mutex_lock(&data->lock);
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	pmcmsptwi_reg_to_cfg(pmcmsptwi_readl(
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				data->iobase + MSP_TWI_CFG_REG_OFFSET), cfg);
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	mutex_unlock(&data->lock);
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}
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/*
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 * Sets the current TWI bus configuration
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 */
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static void pmcmsptwi_set_twi_config(const struct pmcmsptwi_cfg *cfg,
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					struct pmcmsptwi_data *data)
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{
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	mutex_lock(&data->lock);
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	pmcmsptwi_writel(pmcmsptwi_cfg_to_reg(cfg),
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				data->iobase + MSP_TWI_CFG_REG_OFFSET);
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	mutex_unlock(&data->lock);
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}
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/*
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 * Parses the 'int_sts' register and returns a well-defined error code
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 */
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static enum pmcmsptwi_xfer_result pmcmsptwi_get_result(u32 reg)
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{
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	if (reg & MSP_TWI_INT_STS_LOST_ARBITRATION) {
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		dev_dbg(&pmcmsptwi_adapter.dev,
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			"Result: Lost arbitration\n");
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		return MSP_TWI_XFER_LOST_ARBITRATION;
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	} else if (reg & MSP_TWI_INT_STS_NO_RESPONSE) {
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		dev_dbg(&pmcmsptwi_adapter.dev,
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			"Result: No response\n");
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		return MSP_TWI_XFER_NO_RESPONSE;
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	} else if (reg & MSP_TWI_INT_STS_DATA_COLLISION) {
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		dev_dbg(&pmcmsptwi_adapter.dev,
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			"Result: Data collision\n");
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		return MSP_TWI_XFER_DATA_COLLISION;
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	} else if (reg & MSP_TWI_INT_STS_BUSY) {
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		dev_dbg(&pmcmsptwi_adapter.dev,
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			"Result: Bus busy\n");
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		return MSP_TWI_XFER_BUSY;
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	}
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	dev_dbg(&pmcmsptwi_adapter.dev, "Result: Operation succeeded\n");
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	return MSP_TWI_XFER_OK;
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}
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/*
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 * In interrupt mode, handle the interrupt.
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 * NOTE: Assumes data->lock is held.
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 */
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static irqreturn_t pmcmsptwi_interrupt(int irq, void *ptr)
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{
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	struct pmcmsptwi_data *data = ptr;
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	u32 reason = pmcmsptwi_readl(data->iobase +
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					MSP_TWI_INT_STS_REG_OFFSET);
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	pmcmsptwi_writel(reason, data->iobase + MSP_TWI_INT_STS_REG_OFFSET);
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	dev_dbg(&pmcmsptwi_adapter.dev, "Got interrupt 0x%08x\n", reason);
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	if (!(reason & MSP_TWI_INT_STS_DONE))
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		return IRQ_NONE;
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	data->last_result = pmcmsptwi_get_result(reason);
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	complete(&data->wait);
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	return IRQ_HANDLED;
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}
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/*
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 * Probe for and register the device and return 0 if there is one.
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 */
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static int __devinit pmcmsptwi_probe(struct platform_device *pldev)
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{
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	struct resource *res;
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	int rc = -ENODEV;
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	/* get the static platform resources */
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	res = platform_get_resource(pldev, IORESOURCE_MEM, 0);
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	if (!res) {
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		dev_err(&pldev->dev, "IOMEM resource not found\n");
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		goto ret_err;
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	}
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	/* reserve the memory region */
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	if (!request_mem_region(res->start, res->end - res->start + 1,
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				pldev->name)) {
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		dev_err(&pldev->dev,
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			"Unable to get memory/io address region 0x%08x\n",
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			res->start);
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		rc = -EBUSY;
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		goto ret_err;
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	}
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	/* remap the memory */
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	pmcmsptwi_data.iobase = ioremap_nocache(res->start,
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						res->end - res->start + 1);
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	if (!pmcmsptwi_data.iobase) {
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		dev_err(&pldev->dev,
 | 
			
		||||
			"Unable to ioremap address 0x%08x\n", res->start);
 | 
			
		||||
		rc = -EIO;
 | 
			
		||||
		goto ret_unreserve;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	/* request the irq */
 | 
			
		||||
	pmcmsptwi_data.irq = platform_get_irq(pldev, 0);
 | 
			
		||||
	if (pmcmsptwi_data.irq) {
 | 
			
		||||
		rc = request_irq(pmcmsptwi_data.irq, &pmcmsptwi_interrupt,
 | 
			
		||||
			IRQF_SHARED | IRQF_DISABLED | IRQF_SAMPLE_RANDOM,
 | 
			
		||||
			pldev->name, &pmcmsptwi_data);
 | 
			
		||||
		if (rc == 0) {
 | 
			
		||||
			/*
 | 
			
		||||
			 * Enable 'DONE' interrupt only.
 | 
			
		||||
			 *
 | 
			
		||||
			 * If you enable all interrupts, you will get one on
 | 
			
		||||
			 * error and another when the operation completes.
 | 
			
		||||
			 * This way you only have to handle one interrupt,
 | 
			
		||||
			 * but you can still check all result flags.
 | 
			
		||||
			 */
 | 
			
		||||
			pmcmsptwi_writel(MSP_TWI_INT_STS_DONE,
 | 
			
		||||
					pmcmsptwi_data.iobase +
 | 
			
		||||
					MSP_TWI_INT_MSK_REG_OFFSET);
 | 
			
		||||
		} else {
 | 
			
		||||
			dev_warn(&pldev->dev,
 | 
			
		||||
				"Could not assign TWI IRQ handler "
 | 
			
		||||
				"to irq %d (continuing with poll)\n",
 | 
			
		||||
				pmcmsptwi_data.irq);
 | 
			
		||||
			pmcmsptwi_data.irq = 0;
 | 
			
		||||
		}
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	init_completion(&pmcmsptwi_data.wait);
 | 
			
		||||
	mutex_init(&pmcmsptwi_data.lock);
 | 
			
		||||
 | 
			
		||||
	pmcmsptwi_set_clock_config(&pmcmsptwi_defclockcfg, &pmcmsptwi_data);
 | 
			
		||||
	pmcmsptwi_set_twi_config(&pmcmsptwi_defcfg, &pmcmsptwi_data);
 | 
			
		||||
 | 
			
		||||
	printk(KERN_INFO DRV_NAME ": Registering MSP71xx I2C adapter\n");
 | 
			
		||||
 | 
			
		||||
	pmcmsptwi_adapter.dev.parent = &pldev->dev;
 | 
			
		||||
	platform_set_drvdata(pldev, &pmcmsptwi_adapter);
 | 
			
		||||
	i2c_set_adapdata(&pmcmsptwi_adapter, &pmcmsptwi_data);
 | 
			
		||||
 | 
			
		||||
	rc = i2c_add_adapter(&pmcmsptwi_adapter);
 | 
			
		||||
	if (rc) {
 | 
			
		||||
		dev_err(&pldev->dev, "Unable to register I2C adapter\n");
 | 
			
		||||
		goto ret_unmap;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	return 0;
 | 
			
		||||
 | 
			
		||||
ret_unmap:
 | 
			
		||||
	platform_set_drvdata(pldev, NULL);
 | 
			
		||||
	if (pmcmsptwi_data.irq) {
 | 
			
		||||
		pmcmsptwi_writel(0,
 | 
			
		||||
			pmcmsptwi_data.iobase + MSP_TWI_INT_MSK_REG_OFFSET);
 | 
			
		||||
		free_irq(pmcmsptwi_data.irq, &pmcmsptwi_data);
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	iounmap(pmcmsptwi_data.iobase);
 | 
			
		||||
 | 
			
		||||
ret_unreserve:
 | 
			
		||||
	release_mem_region(res->start, res->end - res->start + 1);
 | 
			
		||||
 | 
			
		||||
ret_err:
 | 
			
		||||
	return rc;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/*
 | 
			
		||||
 * Release the device and return 0 if there is one.
 | 
			
		||||
 */
 | 
			
		||||
static int __devexit pmcmsptwi_remove(struct platform_device *pldev)
 | 
			
		||||
{
 | 
			
		||||
	struct resource *res;
 | 
			
		||||
 | 
			
		||||
	i2c_del_adapter(&pmcmsptwi_adapter);
 | 
			
		||||
 | 
			
		||||
	platform_set_drvdata(pldev, NULL);
 | 
			
		||||
	if (pmcmsptwi_data.irq) {
 | 
			
		||||
		pmcmsptwi_writel(0,
 | 
			
		||||
			pmcmsptwi_data.iobase + MSP_TWI_INT_MSK_REG_OFFSET);
 | 
			
		||||
		free_irq(pmcmsptwi_data.irq, &pmcmsptwi_data);
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	iounmap(pmcmsptwi_data.iobase);
 | 
			
		||||
 | 
			
		||||
	res = platform_get_resource(pldev, IORESOURCE_MEM, 0);
 | 
			
		||||
	release_mem_region(res->start, res->end - res->start + 1);
 | 
			
		||||
 | 
			
		||||
	return 0;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/*
 | 
			
		||||
 * Polls the 'busy' register until the command is complete.
 | 
			
		||||
 * NOTE: Assumes data->lock is held.
 | 
			
		||||
 */
 | 
			
		||||
static void pmcmsptwi_poll_complete(struct pmcmsptwi_data *data)
 | 
			
		||||
{
 | 
			
		||||
	int i;
 | 
			
		||||
 | 
			
		||||
	for (i = 0; i < MSP_MAX_POLL; i++) {
 | 
			
		||||
		u32 val = pmcmsptwi_readl(data->iobase +
 | 
			
		||||
						MSP_TWI_BUSY_REG_OFFSET);
 | 
			
		||||
		if (val == 0) {
 | 
			
		||||
			u32 reason = pmcmsptwi_readl(data->iobase +
 | 
			
		||||
						MSP_TWI_INT_STS_REG_OFFSET);
 | 
			
		||||
			pmcmsptwi_writel(reason, data->iobase +
 | 
			
		||||
						MSP_TWI_INT_STS_REG_OFFSET);
 | 
			
		||||
			data->last_result = pmcmsptwi_get_result(reason);
 | 
			
		||||
			return;
 | 
			
		||||
		}
 | 
			
		||||
		udelay(MSP_POLL_DELAY);
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	dev_dbg(&pmcmsptwi_adapter.dev, "Result: Poll timeout\n");
 | 
			
		||||
	data->last_result = MSP_TWI_XFER_TIMEOUT;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/*
 | 
			
		||||
 * Do the transfer (low level):
 | 
			
		||||
 *   May use interrupt-driven or polling, depending on if an IRQ is
 | 
			
		||||
 *   presently registered.
 | 
			
		||||
 * NOTE: Assumes data->lock is held.
 | 
			
		||||
 */
 | 
			
		||||
static enum pmcmsptwi_xfer_result pmcmsptwi_do_xfer(
 | 
			
		||||
			u32 reg, struct pmcmsptwi_data *data)
 | 
			
		||||
{
 | 
			
		||||
	dev_dbg(&pmcmsptwi_adapter.dev, "Writing cmd reg 0x%08x\n", reg);
 | 
			
		||||
	pmcmsptwi_writel(reg, data->iobase + MSP_TWI_CMD_REG_OFFSET);
 | 
			
		||||
	if (data->irq) {
 | 
			
		||||
		unsigned long timeleft = wait_for_completion_timeout(
 | 
			
		||||
						&data->wait, MSP_IRQ_TIMEOUT);
 | 
			
		||||
		if (timeleft == 0) {
 | 
			
		||||
			dev_dbg(&pmcmsptwi_adapter.dev,
 | 
			
		||||
				"Result: IRQ timeout\n");
 | 
			
		||||
			complete(&data->wait);
 | 
			
		||||
			data->last_result = MSP_TWI_XFER_TIMEOUT;
 | 
			
		||||
		}
 | 
			
		||||
	} else
 | 
			
		||||
		pmcmsptwi_poll_complete(data);
 | 
			
		||||
 | 
			
		||||
	return data->last_result;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/*
 | 
			
		||||
 * Helper routine, converts 'pmctwi_cmd' struct to register format
 | 
			
		||||
 */
 | 
			
		||||
static inline u32 pmcmsptwi_cmd_to_reg(const struct pmcmsptwi_cmd *cmd)
 | 
			
		||||
{
 | 
			
		||||
	return ((cmd->type & 0x3) << 8) |
 | 
			
		||||
		(((cmd->write_len - 1) & 0x7) << 4) |
 | 
			
		||||
		((cmd->read_len - 1) & 0x7);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/*
 | 
			
		||||
 * Do the transfer (high level)
 | 
			
		||||
 */
 | 
			
		||||
static enum pmcmsptwi_xfer_result pmcmsptwi_xfer_cmd(
 | 
			
		||||
			struct pmcmsptwi_cmd *cmd,
 | 
			
		||||
			struct pmcmsptwi_data *data)
 | 
			
		||||
{
 | 
			
		||||
	enum pmcmsptwi_xfer_result retval;
 | 
			
		||||
 | 
			
		||||
	if ((cmd->type == MSP_TWI_CMD_WRITE && cmd->write_len == 0) ||
 | 
			
		||||
	    (cmd->type == MSP_TWI_CMD_READ && cmd->read_len == 0) ||
 | 
			
		||||
	    (cmd->type == MSP_TWI_CMD_WRITE_READ &&
 | 
			
		||||
	    (cmd->read_len == 0 || cmd->write_len == 0))) {
 | 
			
		||||
		dev_err(&pmcmsptwi_adapter.dev,
 | 
			
		||||
			"%s: Cannot transfer less than 1 byte\n",
 | 
			
		||||
			__FUNCTION__);
 | 
			
		||||
		return -EINVAL;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	if (cmd->read_len > MSP_MAX_BYTES_PER_RW ||
 | 
			
		||||
	    cmd->write_len > MSP_MAX_BYTES_PER_RW) {
 | 
			
		||||
		dev_err(&pmcmsptwi_adapter.dev,
 | 
			
		||||
			"%s: Cannot transfer more than %d bytes\n",
 | 
			
		||||
			__FUNCTION__, MSP_MAX_BYTES_PER_RW);
 | 
			
		||||
		return -EINVAL;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	mutex_lock(&data->lock);
 | 
			
		||||
	dev_dbg(&pmcmsptwi_adapter.dev,
 | 
			
		||||
		"Setting address to 0x%04x\n", cmd->addr);
 | 
			
		||||
	pmcmsptwi_writel(cmd->addr, data->iobase + MSP_TWI_ADD_REG_OFFSET);
 | 
			
		||||
 | 
			
		||||
	if (cmd->type == MSP_TWI_CMD_WRITE ||
 | 
			
		||||
	    cmd->type == MSP_TWI_CMD_WRITE_READ) {
 | 
			
		||||
		__be64 tmp = cpu_to_be64p((u64 *)cmd->write_data);
 | 
			
		||||
		tmp >>= (MSP_MAX_BYTES_PER_RW - cmd->write_len) * 8;
 | 
			
		||||
		dev_dbg(&pmcmsptwi_adapter.dev, "Writing 0x%016llx\n", tmp);
 | 
			
		||||
		pmcmsptwi_writel(tmp & 0x00000000ffffffffLL,
 | 
			
		||||
				data->iobase + MSP_TWI_DAT_0_REG_OFFSET);
 | 
			
		||||
		if (cmd->write_len > 4)
 | 
			
		||||
			pmcmsptwi_writel(tmp >> 32,
 | 
			
		||||
				data->iobase + MSP_TWI_DAT_1_REG_OFFSET);
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	retval = pmcmsptwi_do_xfer(pmcmsptwi_cmd_to_reg(cmd), data);
 | 
			
		||||
	if (retval != MSP_TWI_XFER_OK)
 | 
			
		||||
		goto xfer_err;
 | 
			
		||||
 | 
			
		||||
	if (cmd->type == MSP_TWI_CMD_READ ||
 | 
			
		||||
	    cmd->type == MSP_TWI_CMD_WRITE_READ) {
 | 
			
		||||
		int i;
 | 
			
		||||
		u64 rmsk = ~(0xffffffffffffffffLL << (cmd->read_len * 8));
 | 
			
		||||
		u64 tmp = (u64)pmcmsptwi_readl(data->iobase +
 | 
			
		||||
					MSP_TWI_DAT_0_REG_OFFSET);
 | 
			
		||||
		if (cmd->read_len > 4)
 | 
			
		||||
			tmp |= (u64)pmcmsptwi_readl(data->iobase +
 | 
			
		||||
					MSP_TWI_DAT_1_REG_OFFSET) << 32;
 | 
			
		||||
		tmp &= rmsk;
 | 
			
		||||
		dev_dbg(&pmcmsptwi_adapter.dev, "Read 0x%016llx\n", tmp);
 | 
			
		||||
 | 
			
		||||
		for (i = 0; i < cmd->read_len; i++)
 | 
			
		||||
			cmd->read_data[i] = tmp >> i;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
xfer_err:
 | 
			
		||||
	mutex_unlock(&data->lock);
 | 
			
		||||
 | 
			
		||||
	return retval;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/* -- Algorithm functions -- */
 | 
			
		||||
 | 
			
		||||
/*
 | 
			
		||||
 * Sends an i2c command out on the adapter
 | 
			
		||||
 */
 | 
			
		||||
static int pmcmsptwi_master_xfer(struct i2c_adapter *adap,
 | 
			
		||||
				struct i2c_msg *msg, int num)
 | 
			
		||||
{
 | 
			
		||||
	struct pmcmsptwi_data *data = i2c_get_adapdata(adap);
 | 
			
		||||
	struct pmcmsptwi_cmd cmd;
 | 
			
		||||
	struct pmcmsptwi_cfg oldcfg, newcfg;
 | 
			
		||||
	int ret;
 | 
			
		||||
 | 
			
		||||
	if (num > 2) {
 | 
			
		||||
		dev_dbg(&adap->dev, "%d messages unsupported\n", num);
 | 
			
		||||
		return -EINVAL;
 | 
			
		||||
	} else if (num == 2) {
 | 
			
		||||
		/* Check for a dual write-then-read command */
 | 
			
		||||
		struct i2c_msg *nextmsg = msg + 1;
 | 
			
		||||
		if (!(msg->flags & I2C_M_RD) &&
 | 
			
		||||
		    (nextmsg->flags & I2C_M_RD) &&
 | 
			
		||||
		    msg->addr == nextmsg->addr) {
 | 
			
		||||
			cmd.type = MSP_TWI_CMD_WRITE_READ;
 | 
			
		||||
			cmd.write_len = msg->len;
 | 
			
		||||
			cmd.write_data = msg->buf;
 | 
			
		||||
			cmd.read_len = nextmsg->len;
 | 
			
		||||
			cmd.read_data = nextmsg->buf;
 | 
			
		||||
		} else {
 | 
			
		||||
			dev_dbg(&adap->dev,
 | 
			
		||||
				"Non write-read dual messages unsupported\n");
 | 
			
		||||
			return -EINVAL;
 | 
			
		||||
		}
 | 
			
		||||
	} else if (msg->flags & I2C_M_RD) {
 | 
			
		||||
		cmd.type = MSP_TWI_CMD_READ;
 | 
			
		||||
		cmd.read_len = msg->len;
 | 
			
		||||
		cmd.read_data = msg->buf;
 | 
			
		||||
		cmd.write_len = 0;
 | 
			
		||||
		cmd.write_data = NULL;
 | 
			
		||||
	} else {
 | 
			
		||||
		cmd.type = MSP_TWI_CMD_WRITE;
 | 
			
		||||
		cmd.read_len = 0;
 | 
			
		||||
		cmd.read_data = NULL;
 | 
			
		||||
		cmd.write_len = msg->len;
 | 
			
		||||
		cmd.write_data = msg->buf;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	if (msg->len == 0) {
 | 
			
		||||
		dev_err(&adap->dev, "Zero-byte messages unsupported\n");
 | 
			
		||||
		return -EINVAL;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	cmd.addr = msg->addr;
 | 
			
		||||
 | 
			
		||||
	if (msg->flags & I2C_M_TEN) {
 | 
			
		||||
		pmcmsptwi_get_twi_config(&newcfg, data);
 | 
			
		||||
		memcpy(&oldcfg, &newcfg, sizeof(oldcfg));
 | 
			
		||||
 | 
			
		||||
		/* Set the special 10-bit address flag */
 | 
			
		||||
		newcfg.add10 = 1;
 | 
			
		||||
 | 
			
		||||
		pmcmsptwi_set_twi_config(&newcfg, data);
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	/* Execute the command */
 | 
			
		||||
	ret = pmcmsptwi_xfer_cmd(&cmd, data);
 | 
			
		||||
 | 
			
		||||
	if (msg->flags & I2C_M_TEN)
 | 
			
		||||
		pmcmsptwi_set_twi_config(&oldcfg, data);
 | 
			
		||||
 | 
			
		||||
	dev_dbg(&adap->dev, "I2C %s of %d bytes ",
 | 
			
		||||
		(msg->flags & I2C_M_RD) ? "read" : "write", msg->len);
 | 
			
		||||
	if (ret != MSP_TWI_XFER_OK) {
 | 
			
		||||
		/*
 | 
			
		||||
		 * TODO: We could potentially loop and retry in the case
 | 
			
		||||
		 * of MSP_TWI_XFER_TIMEOUT.
 | 
			
		||||
		 */
 | 
			
		||||
		dev_dbg(&adap->dev, "failed\n");
 | 
			
		||||
		return -1;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	dev_dbg(&adap->dev, "succeeded\n");
 | 
			
		||||
	return 0;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static u32 pmcmsptwi_i2c_func(struct i2c_adapter *adapter)
 | 
			
		||||
{
 | 
			
		||||
	return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR |
 | 
			
		||||
		I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA |
 | 
			
		||||
		I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_PROC_CALL;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/* -- Initialization -- */
 | 
			
		||||
 | 
			
		||||
static struct i2c_algorithm pmcmsptwi_algo = {
 | 
			
		||||
	.master_xfer	= pmcmsptwi_master_xfer,
 | 
			
		||||
	.functionality	= pmcmsptwi_i2c_func,
 | 
			
		||||
};
 | 
			
		||||
 | 
			
		||||
static struct i2c_adapter pmcmsptwi_adapter = {
 | 
			
		||||
	.owner		= THIS_MODULE,
 | 
			
		||||
	.class		= I2C_CLASS_HWMON,
 | 
			
		||||
	.algo		= &pmcmsptwi_algo,
 | 
			
		||||
	.name		= DRV_NAME,
 | 
			
		||||
};
 | 
			
		||||
 | 
			
		||||
static struct platform_driver pmcmsptwi_driver = {
 | 
			
		||||
	.probe  = pmcmsptwi_probe,
 | 
			
		||||
	.remove	= __devexit_p(pmcmsptwi_remove),
 | 
			
		||||
	.driver {
 | 
			
		||||
		.name	= DRV_NAME,
 | 
			
		||||
		.owner	= THIS_MODULE,
 | 
			
		||||
	},
 | 
			
		||||
};
 | 
			
		||||
 | 
			
		||||
static int __init pmcmsptwi_init(void)
 | 
			
		||||
{
 | 
			
		||||
	return platform_driver_register(&pmcmsptwi_driver);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static void __exit pmcmsptwi_exit(void)
 | 
			
		||||
{
 | 
			
		||||
	platform_driver_unregister(&pmcmsptwi_driver);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
MODULE_DESCRIPTION("PMC MSP TWI/SMBus/I2C driver");
 | 
			
		||||
MODULE_LICENSE("GPL");
 | 
			
		||||
 | 
			
		||||
module_init(pmcmsptwi_init);
 | 
			
		||||
module_exit(pmcmsptwi_exit);
 | 
			
		||||
		Loading…
	
		Reference in a new issue