From: Hemanth V <[email protected]> This patch adds context save/restore feature to McSPI driver. This has been tested by instrumenting the driver code i.e by adding a McSPI softreset in omap2_mcspi_disable_clocks function.
Signed-off-by: Hemanth V <[email protected]> --- drivers/spi/omap2_mcspi.c | 88 +++++++++++++++++++++++++++++++++++++++------- 1 files changed, 76 insertions(+), 12 deletions(-) Index: linux-omap-2.6/drivers/spi/omap2_mcspi.c =================================================================== --- linux-omap-2.6.orig/drivers/spi/omap2_mcspi.c 2009-01-21 15:03:12.000000000 +0530 +++ linux-omap-2.6/drivers/spi/omap2_mcspi.c 2009-01-21 15:05:20.000000000 +0530 @@ -133,6 +133,15 @@ int word_len; }; +struct omap2_mcspi_regs { + u32 sysconfig; + u32 modulctrl; + u32 chconf0; + u32 wakeupenable; +}; + +static struct omap2_mcspi_regs omap2_mcspi_ctx[4]; + static struct workqueue_struct *omap2_mcspi_wq; #define MOD_REG_BIT(val, mask, set) do { \ @@ -219,6 +228,63 @@ mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l); } +static void omap2_mcspi_save_ctx(struct omap2_mcspi *mcspi) +{ + struct spi_master *spi_cntrl; + spi_cntrl = mcspi->master; + + /* McSPI : context save */ + omap2_mcspi_ctx[spi_cntrl->bus_num - 1].modulctrl = + mcspi_read_reg(spi_cntrl, OMAP2_MCSPI_MODULCTRL); + + omap2_mcspi_ctx[spi_cntrl->bus_num - 1].sysconfig = + mcspi_read_reg(spi_cntrl, OMAP2_MCSPI_SYSCONFIG); + + omap2_mcspi_ctx[spi_cntrl->bus_num - 1].chconf0 = + mcspi_read_reg(spi_cntrl, OMAP2_MCSPI_CHCONF0); + + omap2_mcspi_ctx[spi_cntrl->bus_num - 1].wakeupenable = + mcspi_read_reg(spi_cntrl, OMAP2_MCSPI_WAKEUPENABLE); +} + +static void omap2_mcspi_restore_ctx(struct omap2_mcspi *mcspi) +{ + struct spi_master *spi_cntrl; + spi_cntrl = mcspi->master; + + /*McSPI : context restore */ + mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_MODULCTRL, + omap2_mcspi_ctx[spi_cntrl->bus_num - 1].modulctrl); + + mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_SYSCONFIG, + omap2_mcspi_ctx[spi_cntrl->bus_num - 1].sysconfig); + + mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_CHCONF0, + omap2_mcspi_ctx[spi_cntrl->bus_num - 1].chconf0); + + mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_WAKEUPENABLE, + omap2_mcspi_ctx[spi_cntrl->bus_num - 1].wakeupenable); +} +static void omap2_mcspi_disable_clocks(struct omap2_mcspi *mcspi) +{ + omap2_mcspi_save_ctx(mcspi); + + clk_disable(mcspi->ick); + clk_disable(mcspi->fck); +} + +static int omap2_mcspi_enable_clocks(struct omap2_mcspi *mcspi) +{ + if (clk_enable(mcspi->ick)) + return -ENODEV; + if (clk_enable(mcspi->fck)) + return -ENODEV; + + omap2_mcspi_restore_ctx(mcspi); + + return 0; +} + static unsigned omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer) { @@ -649,11 +715,11 @@ return ret; } - clk_enable(mcspi->ick); - clk_enable(mcspi->fck); + if (omap2_mcspi_enable_clocks(mcspi)) + return -ENODEV; + ret = omap2_mcspi_setup_transfer(spi, NULL); - clk_disable(mcspi->fck); - clk_disable(mcspi->ick); + omap2_mcspi_disable_clocks(mcspi); return ret; } @@ -685,8 +751,8 @@ mcspi = container_of(work, struct omap2_mcspi, work); spin_lock_irq(&mcspi->lock); - clk_enable(mcspi->ick); - clk_enable(mcspi->fck); + if (omap2_mcspi_enable_clocks(mcspi)) + return; /* We only enable one channel at a time -- the one whose message is * at the head of the queue -- although this controller would gladly @@ -788,8 +854,7 @@ spin_lock_irq(&mcspi->lock); } - clk_disable(mcspi->fck); - clk_disable(mcspi->ick); + omap2_mcspi_disable_clocks(mcspi); spin_unlock_irq(&mcspi->lock); } @@ -877,8 +942,8 @@ struct spi_master *master = mcspi->master; u32 tmp; - clk_enable(mcspi->ick); - clk_enable(mcspi->fck); + if (omap2_mcspi_enable_clocks(mcspi)) + return -1; mcspi_write_reg(master, OMAP2_MCSPI_SYSCONFIG, OMAP2_MCSPI_SYSCONFIG_SOFTRESET); @@ -896,8 +961,7 @@ omap2_mcspi_set_master_mode(master); - clk_disable(mcspi->fck); - clk_disable(mcspi->ick); + omap2_mcspi_disable_clocks(mcspi); return 0; } -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
