From 47dcd0161a0b37bf0299473585fc5030d3f45b64 Mon Sep 17 00:00:00 2001 From: Shubhrajyoti D Date: Mon, 5 Nov 2012 17:53:36 +0530 Subject: [PATCH] i2c: omap: Fix the revision register read The revision register on OMAP4 is a 16-bit lo and a 16-bit hi. Currently the driver reads only the lower 8-bits. Fix the same by preventing the truncating of the rev register for OMAP4. Also use the scheme bit ie bit-14 of the hi register to know if it is OMAP_I2C_IP_VERSION_2. On platforms previous to OMAP4 the offset 0x04 is IE register whose bit-14 reset value is 0, the code uses the same to its advantage. Also since the omap_i2c_read_reg uses reg_map_ip_* a raw_readw is done to fetch the revision register. The dev->regs is populated after reading the rev_hi. A NULL check has been added in the resume handler to prevent the access before the setting of the regs. Signed-off-by: Shubhrajyoti D Reviewed-by: Felipe Balbi Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-omap.c | 61 ++++++++++++++++++++++++++++++++++--------- 1 file changed, 48 insertions(+), 13 deletions(-) diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c index 16afb28..bf0569e 100644 --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -49,9 +49,10 @@ #define OMAP_I2C_OMAP1_REV_2 0x20 /* I2C controller revisions present on specific hardware */ -#define OMAP_I2C_REV_ON_2430 0x36 -#define OMAP_I2C_REV_ON_3430_3530 0x3C -#define OMAP_I2C_REV_ON_3630_4430 0x40 +#define OMAP_I2C_REV_ON_2430 0x00000036 +#define OMAP_I2C_REV_ON_3430_3530 0x0000003C +#define OMAP_I2C_REV_ON_3630 0x00000040 +#define OMAP_I2C_REV_ON_4430_PLUS 0x50400002 /* timeout waiting for the controller to respond */ #define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000)) @@ -203,7 +204,7 @@ struct omap_i2c_dev { * fifo_size==0 implies no fifo * if set, should be trsh+1 */ - u8 rev; + u32 rev; unsigned b_hw:1; /* bad h/w fixes */ unsigned receiver:1; /* true when we're in receiver mode */ u16 iestate; /* Saved interrupt register */ @@ -493,7 +494,7 @@ static void omap_i2c_resize_fifo(struct omap_i2c_dev *dev, u8 size, bool is_rx) omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, buf); - if (dev->rev < OMAP_I2C_REV_ON_3630_4430) + if (dev->rev < OMAP_I2C_REV_ON_3630) dev->b_hw = 1; /* Enable hardware fixes */ /* calculate wakeup latency constraint for MPU */ @@ -1051,6 +1052,16 @@ static const struct of_device_id omap_i2c_of_match[] = { MODULE_DEVICE_TABLE(of, omap_i2c_of_match); #endif +#define OMAP_I2C_SCHEME(rev) ((rev & 0xc000) >> 14) + +#define OMAP_I2C_REV_SCHEME_0_MAJOR(rev) (rev >> 4) +#define OMAP_I2C_REV_SCHEME_0_MINOR(rev) (rev & 0xf) + +#define OMAP_I2C_REV_SCHEME_1_MAJOR(rev) ((rev & 0x0700) >> 7) +#define OMAP_I2C_REV_SCHEME_1_MINOR(rev) (rev & 0x1f) +#define OMAP_I2C_SCHEME_0 0 +#define OMAP_I2C_SCHEME_1 1 + static int __devinit omap_i2c_probe(struct platform_device *pdev) { @@ -1063,6 +1074,8 @@ omap_i2c_probe(struct platform_device *pdev) const struct of_device_id *match; int irq; int r; + u32 rev; + u16 minor, major; /* NOTE: driver uses the static register mapping */ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); @@ -1127,11 +1140,6 @@ omap_i2c_probe(struct platform_device *pdev) dev->reg_shift = (dev->flags >> OMAP_I2C_FLAG_BUS_SHIFT__SHIFT) & 3; - if (dev->dtrev == OMAP_I2C_IP_VERSION_2) - dev->regs = (u8 *)reg_map_ip_v2; - else - dev->regs = (u8 *)reg_map_ip_v1; - pm_runtime_enable(dev->dev); pm_runtime_set_autosuspend_delay(dev->dev, OMAP_I2C_PM_TIMEOUT); pm_runtime_use_autosuspend(dev->dev); @@ -1140,7 +1148,31 @@ omap_i2c_probe(struct platform_device *pdev) if (IS_ERR_VALUE(r)) goto err_free_mem; - dev->rev = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff; + /* + * Read the Rev hi bit-[15:14] ie scheme this is 1 indicates ver2. + * On omap1/3/2 Offset 4 is IE Reg the bit [15:14] is 0 at reset. + * Also since the omap_i2c_read_reg uses reg_map_ip_* a + * raw_readw is done. + */ + rev = __raw_readw(dev->base + 0x04); + + switch (OMAP_I2C_SCHEME(rev)) { + case OMAP_I2C_SCHEME_0: + dev->regs = (u8 *)reg_map_ip_v1; + dev->rev = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG); + minor = OMAP_I2C_REV_SCHEME_0_MAJOR(dev->rev); + major = OMAP_I2C_REV_SCHEME_0_MAJOR(dev->rev); + break; + case OMAP_I2C_SCHEME_1: + /* FALLTHROUGH */ + default: + dev->regs = (u8 *)reg_map_ip_v2; + rev = (rev << 16) | + omap_i2c_read_reg(dev, OMAP_I2C_IP_V2_REVNB_LO); + minor = OMAP_I2C_REV_SCHEME_1_MINOR(rev); + major = OMAP_I2C_REV_SCHEME_1_MAJOR(rev); + dev->rev = rev; + } dev->errata = 0; @@ -1165,7 +1197,7 @@ omap_i2c_probe(struct platform_device *pdev) dev->fifo_size = (dev->fifo_size / 2); - if (dev->rev < OMAP_I2C_REV_ON_3630_4430) + if (dev->rev < OMAP_I2C_REV_ON_3630) dev->b_hw = 1; /* Enable hardware fixes */ /* calculate wakeup latency constraint for MPU */ @@ -1209,7 +1241,7 @@ omap_i2c_probe(struct platform_device *pdev) } dev_info(dev->dev, "bus %d rev%d.%d.%d at %d kHz\n", adap->nr, - dev->dtrev, dev->rev >> 4, dev->rev & 0xf, dev->speed); + dev->dtrev, major, minor, dev->speed); of_i2c_register_devices(adap); @@ -1275,6 +1307,9 @@ static int omap_i2c_runtime_resume(struct device *dev) struct platform_device *pdev = to_platform_device(dev); struct omap_i2c_dev *_dev = platform_get_drvdata(pdev); + if (!_dev->regs) + return 0; + if (_dev->flags & OMAP_I2C_FLAG_RESET_REGS_POSTIDLE) { omap_i2c_write_reg(_dev, OMAP_I2C_CON_REG, 0); omap_i2c_write_reg(_dev, OMAP_I2C_PSC_REG, _dev->pscstate); -- 2.7.4