SPI: Merge improved clock management from N800 tree into OMAP2 McSPI

Patch makes the OMAP2 McSPI module to use interface and functional clocks
only when needed and inserts timeout handling in function
omap2_mcspi_txrx_pio.

These are originally developed by Samuel Ortiz <samuel.ortiz@solidboot.com>
and Juha Yrjola <juha.yrjola@solidboot.com>.

Signed-off-by: Jarkko Nikula <jarkko.nikula@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c
index e558187e70a89a6fe6a05a3e1f1d397c8eb75a27..5f38556195b559f1dd93eb60246dd555c1e8f6ff 100644 (file)
--- a/drivers/spi/omap2_mcspi.c
+++ b/drivers/spi/omap2_mcspi.c
@@ -37,6 +37,7 @@
 #include <asm/io.h>
 #include <asm/arch/dma.h>
 #include <asm/arch/mcspi.h>
+#include <asm/arch/clock.h>
 
 #define OMAP2_MCSPI_MAX_FREQ           48000000
 
@@ -248,7 +249,7 @@ static void omap2_mcspi_txrx_dma(struct spi_device *spi,
                data_type = OMAP_DMA_DATA_TYPE_S32;
                element_count = count >> 2;
        } else
-               return;
+               goto out;
 
        /* RX_ONLY mode needs dummy data in TX reg */
        if (tx == NULL)
@@ -287,7 +288,7 @@ static void omap2_mcspi_txrx_dma(struct spi_device *spi,
                        if (tx != NULL)
                                dma_unmap_single(NULL, xfer->tx_dma,
                                                 count, DMA_TO_DEVICE);
-                       return;
+                       goto out;
                }
 
                omap_set_dma_transfer_params(mcspi_dma->dma_rx_channel,
@@ -323,10 +324,22 @@ static void omap2_mcspi_txrx_dma(struct spi_device *spi,
                wait_for_completion(&mcspi_dma->dma_rx_completion);
                dma_unmap_single(NULL, xfer->rx_dma, count, DMA_FROM_DEVICE);
        }
-
+out:
        omap2_mcspi_set_enable(spi, 0);
 }
 
+static int mcspi_wait_for_reg_bit(unsigned long reg, unsigned long bit)
+{
+       unsigned long timeout;
+
+       timeout = jiffies + msecs_to_jiffies(1000);
+       while (!(__raw_readl(reg) & bit)) {
+               if (time_after(jiffies, timeout))
+                       return -1;
+       }
+       return 0;
+}
+
 static void omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
 {
        struct omap2_mcspi * mcspi;
@@ -371,7 +384,10 @@ static void omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xf
 
                while (c--) {
                        if (tx != NULL) {
-                               while (!(__raw_readl(chstat_reg) & OMAP2_MCSPI_CHSTAT_TXS));
+                               if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_TXS) < 0) {
+                                       dev_err(&spi->dev, "TXS timed out\n");
+                                       goto out;
+                               }
 #ifdef VERBOSE
                                dev_dbg(&spi->dev, "write-%d %02x\n",
                                                word_len, *tx);
@@ -379,7 +395,10 @@ static void omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xf
                                __raw_writel(*tx, tx_reg);
                        }
                        if (rx != NULL) {
-                               while (!(__raw_readl(chstat_reg) & OMAP2_MCSPI_CHSTAT_RXS));
+                               if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_RXS) < 0) {
+                                       dev_err(&spi->dev, "RXS timed out\n");
+                                       goto out;
+                               }
                                if (c == 0 && tx == NULL)
                                        omap2_mcspi_set_enable(spi, 0);
                                *rx++ = __raw_readl(rx_reg);
@@ -398,7 +417,10 @@ static void omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xf
                c >>= 1;
                while (c--) {
                        if (tx != NULL) {
-                               while (!(__raw_readl(chstat_reg) & OMAP2_MCSPI_CHSTAT_TXS));
+                               if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_TXS) < 0) {
+                                       dev_err(&spi->dev, "TXS timed out\n");
+                                       goto out;
+                               }
 #ifdef VERBOSE
                                dev_dbg(&spi->dev, "write-%d %04x\n",
                                                word_len, *tx);
@@ -406,7 +428,10 @@ static void omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xf
                                __raw_writel(*tx++, tx_reg);
                        }
                        if (rx != NULL) {
-                               while (!(__raw_readl(chstat_reg) & OMAP2_MCSPI_CHSTAT_RXS));
+                               if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_RXS) < 0) {
+                                       dev_err(&spi->dev, "RXS timed out\n");
+                                       goto out;
+                               }
                                if (c == 0 && tx == NULL)
                                        omap2_mcspi_set_enable(spi, 0);
                                *rx++ = __raw_readl(rx_reg);
@@ -425,7 +450,10 @@ static void omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xf
                c >>= 2;
                while (c--) {
                        if (tx != NULL) {
-                               while (!(__raw_readl(chstat_reg) & OMAP2_MCSPI_CHSTAT_TXS));
+                               if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_TXS) < 0) {
+                                       dev_err(&spi->dev, "TXS timed out\n");
+                                       goto out;
+                               }
 #ifdef VERBOSE
                                dev_dbg(&spi->dev, "write-%d %04x\n",
                                                word_len, *tx);
@@ -433,7 +461,10 @@ static void omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xf
                                __raw_writel(*tx++, tx_reg);
                        }
                        if (rx != NULL) {
-                               while (!(__raw_readl(chstat_reg) & OMAP2_MCSPI_CHSTAT_RXS));
+                               if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_RXS) < 0) {
+                                       dev_err(&spi->dev, "RXS timed out\n");
+                                       goto out;
+                               }
                                if (c == 0 && tx == NULL)
                                        omap2_mcspi_set_enable(spi, 0);
                                *rx++ = __raw_readl(rx_reg);
@@ -446,8 +477,13 @@ static void omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xf
        }
 
        if (xfer->tx_buf != NULL) {
-               while (!(__raw_readl(chstat_reg) & OMAP2_MCSPI_CHSTAT_TXS));
-               while (!(__raw_readl(chstat_reg) & OMAP2_MCSPI_CHSTAT_EOT));
+               if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_TXS) < 0) {
+                       dev_err(&spi->dev, "TXS timed out\n");
+                       goto out;
+               }
+               if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_EOT) < 0)
+                       dev_err(&spi->dev, "EOT timed out\n");
+out:
                omap2_mcspi_set_enable(spi, 0);
        }
 }
@@ -457,9 +493,12 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi,
 {
        struct omap2_mcspi_cs *cs = spi->controller_state;
        struct omap2_mcspi_device_config *conf;
+       struct omap2_mcspi * mcspi;
        u32 l = 0, div = 0;
        u8 word_len = spi->bits_per_word;
 
+       mcspi = class_get_devdata(&spi->master->cdev);
+
        if (t != NULL && t->bits_per_word)
                word_len = t->bits_per_word;
        if (!word_len)
@@ -471,6 +510,9 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi,
 
        conf = (struct omap2_mcspi_device_config *) spi->controller_data;
 
+       clk_enable(mcspi->ick);
+       clk_enable(mcspi->fck);
+
        if (conf->single_channel == 1)
                omap2_mcspi_set_master_mode(spi, 1);
        else
@@ -486,6 +528,8 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi,
            word_len < 4 || word_len > 32 ||
            div > 15) {
                dev_err(&spi->dev, "Invalid McSPI channel setting\n");
+               clk_disable(mcspi->fck);
+               clk_disable(mcspi->ick);
                return -EINVAL;
        }
 
@@ -516,6 +560,9 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi,
                        (spi->mode & SPI_CPHA) ? "odd" : "even",
                        (spi->mode & SPI_CPOL) ? "" : "not");
 
+       clk_disable(mcspi->fck);
+       clk_disable(mcspi->ick);
+
        return 0;
 }
 
@@ -668,7 +715,6 @@ static void omap2_mcspi_cleanup(struct spi_device *spi)
        }
 }
 
-
 static void omap2_mcspi_work(struct work_struct *work)
 {
        struct omap2_mcspi      *mcspi = container_of(work, struct omap2_mcspi, work);
@@ -709,6 +755,9 @@ static void omap2_mcspi_work(struct work_struct *work)
                                        par_override = 0;
                        }
 
+                       clk_enable(mcspi->ick);
+                       clk_enable(mcspi->fck);
+
                        if (!cs_active) {
                                omap2_mcspi_force_cs(spi, 1);
                                cs_active = 1;
@@ -727,8 +776,12 @@ static void omap2_mcspi_work(struct work_struct *work)
                                        omap2_mcspi_force_cs(spi, 0);
                                cs_active = 0;
                        }
+                       clk_disable(mcspi->ick);
+                       clk_disable(mcspi->fck);
                }
 
+               clk_enable(mcspi->ick);
+               clk_enable(mcspi->fck);
                /* Restore defaults they are overriden */
                if (par_override) {
                        par_override = 0;
@@ -737,6 +790,8 @@ static void omap2_mcspi_work(struct work_struct *work)
 
                if (cs_active)
                        omap2_mcspi_force_cs(spi, 0);
+               clk_disable(mcspi->ick);
+               clk_disable(mcspi->fck);
 
                m->status = status;
                m->complete(m->context);
@@ -831,14 +886,12 @@ static int __devinit omap2_mcspi_probe(struct platform_device *pdev)
                status = PTR_ERR(mcspi->ick);
                goto err1;
        }
-       clk_enable(mcspi->ick);
        mcspi->fck = clk_get(&pdev->dev, "mcspi_fck");
        if (IS_ERR(mcspi->fck)) {
                dev_err(&pdev->dev, "can't get mcspi_fck\n");
                status = PTR_ERR(mcspi->fck);
                goto err2;
        }
-       clk_enable(mcspi->fck);
 
        mcspi->dma_channels =
                (struct omap2_mcspi_dma *)kzalloc(master->num_chipselect *
@@ -865,10 +918,8 @@ static int __devinit omap2_mcspi_probe(struct platform_device *pdev)
 err4:
        kfree(mcspi->dma_channels);
 err3:
-       clk_disable(mcspi->fck);
        clk_put(mcspi->fck);
 err2:
-       clk_disable(mcspi->ick);
        clk_put(mcspi->ick);
 err1:
        class_device_put(&master->cdev);
@@ -885,9 +936,7 @@ static int __devexit omap2_mcspi_remove(struct platform_device *pdev)
 
        spi_unregister_master(master);
        mcspi = class_get_devdata(&master->cdev);
-       clk_disable(mcspi->fck);
        clk_put(mcspi->fck);
-       clk_disable(mcspi->ick);
        clk_put(mcspi->ick);
        class_device_put(&master->cdev);
        kfree(mcspi->dma_channels);