From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jouni Hogander Subject: [PATCH PM-0] OMAP3: I2C: Implement i2c save/restore Date: Wed, 17 Sep 2008 12:45:27 +0300 Message-ID: <1221644727-13809-1-git-send-email-jouni.hogander@nokia.com> References: <87r67kwg97.fsf@trdhcp146196.ntc.nokia.com> Return-path: Received: from smtp.nokia.com ([192.100.122.233]:21196 "EHLO mgw-mx06.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751072AbYIQJoN (ORCPT ); Wed, 17 Sep 2008 05:44:13 -0400 Received: from vaebh105.NOE.Nokia.com (vaebh105.europe.nokia.com [10.160.244.31]) by mgw-mx06.nokia.com (Switch-3.2.6/Switch-3.2.6) with ESMTP id m8H9hmGG008605 for ; Wed, 17 Sep 2008 12:44:10 +0300 In-Reply-To: <87r67kwg97.fsf@trdhcp146196.ntc.nokia.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: linux-omap@vger.kernel.org Save and restore needed registers instead of re-init. Signed-off-by: Jouni Hogander --- drivers/i2c/busses/i2c-omap.c | 47 +++++++++++++++++++++++++++-------------- 1 files changed, 31 insertions(+), 16 deletions(-) diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c index a661ed3..211d7b5 100644 --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -147,6 +147,10 @@ struct omap_i2c_dev { unsigned b_hw:1; /* bad h/w fixes */ unsigned idle:1; u16 iestate; /* Saved interrupt register */ + u16 pscstate; + u16 scllstate; + u16 sclhstate; + u16 bufstate; }; static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev, @@ -209,16 +213,22 @@ static void omap_i2c_unidle(struct omap_i2c_dev *dev) if (dev->iclk != NULL) clk_enable(dev->iclk); clk_enable(dev->fclk); + + if (cpu_is_omap34xx()) { + omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, dev->pscstate); + omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, dev->scllstate); + omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, dev->sclhstate); + omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, dev->bufstate); + } + dev->idle = 0; - if (dev->iestate) - omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate); + omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate); } static void omap_i2c_idle(struct omap_i2c_dev *dev) { u16 iv; - dev->iestate = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG); omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, 0); if (dev->rev1) iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG); @@ -238,7 +248,7 @@ static void omap_i2c_idle(struct omap_i2c_dev *dev) static int omap_i2c_init(struct omap_i2c_dev *dev) { - u16 psc = 0, scll = 0, sclh = 0; + u16 psc = 0, scll = 0, sclh = 0, buf = 0; u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0; unsigned long fclk_rate = 12000000; unsigned long timeout; @@ -327,23 +337,30 @@ static int omap_i2c_init(struct omap_i2c_dev *dev) omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, scll); omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, sclh); - if (dev->fifo_size) - /* Note: setup required fifo size - 1 */ - omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, - (dev->fifo_size - 1) << 8 | /* RTRSH */ - OMAP_I2C_BUF_RXFIF_CLR | - (dev->fifo_size - 1) | /* XTRSH */ - OMAP_I2C_BUF_TXFIF_CLR); + if (dev->fifo_size) { + /* Note: setup required fifo size - 1. RTRSH and XTRSH */ + buf = (dev->fifo_size - 1) << 8 | OMAP_I2C_BUF_RXFIF_CLR | + (dev->fifo_size - 1) | OMAP_I2C_BUF_TXFIF_CLR; + omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, buf); + } /* Take the I2C module out of reset: */ omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN); /* Enable interrupts */ - omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, - (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY | + dev->iestate = (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY | OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK | OMAP_I2C_IE_AL) | ((dev->fifo_size) ? - (OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0)); + (OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0); + omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate); + + if (cpu_is_omap34xx()) { + dev->pscstate = psc; + dev->scllstate = scll; + dev->sclhstate = sclh; + dev->bufstate = buf; + } + return 0; } @@ -503,8 +520,6 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) omap_i2c_unidle(dev); - omap_i2c_init(dev); - if ((r = omap_i2c_wait_for_bb(dev)) < 0) goto out; -- 1.5.5