From: Hemanth V <hemanthv@xxxxxx>
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.
This patch includes review comment fixes
Signed-off-by: Hemanth V <hemanthv@xxxxxx>
---
drivers/spi/omap2_mcspi.c | 97 ++++++++++++++++++++++++++++++++++++----------
1 files changed, 77 insertions(+), 20 deletions(-)
Index: linux-omap-2.6/drivers/spi/omap2_mcspi.c
===================================================================
--- linux-omap-2.6.orig/drivers/spi/omap2_mcspi.c
+++ linux-omap-2.6/drivers/spi/omap2_mcspi.c
@@ -41,6 +41,9 @@
#define OMAP2_MCSPI_MAX_FREQ 48000000
+/* OMAP2 has 3 SPI controllers, while OMAP3 has 4 */
+#define OMAP2_MCSPI_MAX_CTRL 4
+
#define OMAP2_MCSPI_REVISION 0x00
#define OMAP2_MCSPI_SYSCONFIG 0x10
#define OMAP2_MCSPI_SYSSTATUS 0x14
@@ -133,6 +136,18 @@
int word_len;
};
+/* used for context save and restore, structure members to be updated whenever
+ * corresponding registers are modified.
+ */
+struct omap2_mcspi_regs {
+ u32 sysconfig;
+ u32 modulctrl;
+ u32 chconf0;
+ u32 wakeupenable;
+};
+
+static struct omap2_mcspi_regs omap2_mcspi_ctx[OMAP2_MCSPI_MAX_CTRL];
+
static struct workqueue_struct *omap2_mcspi_wq;
#define MOD_REG_BIT(val, mask, set) do { \
@@ -217,6 +232,45 @@
MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_MS, 0);
MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_SINGLE, 1);
mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l);
+
+ omap2_mcspi_ctx[master->bus_num - 1].modulctrl = l;
+}
+
+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)
+{
+ 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
@@ -486,10 +540,12 @@
{
struct omap2_mcspi_cs *cs = spi->controller_state;
struct omap2_mcspi *mcspi;
+ struct spi_master *spi_cntrl;
u32 l = 0, div = 0;
u8 word_len = spi->bits_per_word;
mcspi = spi_master_get_devdata(spi->master);
+ spi_cntrl = mcspi->master;
if (t != NULL && t->bits_per_word)
word_len = t->bits_per_word;
@@ -537,6 +593,8 @@
mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
+ omap2_mcspi_ctx[spi_cntrl->bus_num - 1].chconf0 = l;
+
dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
OMAP2_MCSPI_MAX_FREQ / (1 << div),
(spi->mode & SPI_CPHA) ? "trailing" : "leading",
@@ -649,11 +707,11 @@
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 +743,8 @@
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 +846,7 @@
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 +934,8 @@
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);
@@ -886,18 +943,18 @@
tmp = mcspi_read_reg(master, OMAP2_MCSPI_SYSSTATUS);
} while (!(tmp & OMAP2_MCSPI_SYSSTATUS_RESETDONE));
- mcspi_write_reg(master, OMAP2_MCSPI_SYSCONFIG,
- OMAP2_MCSPI_SYSCONFIG_AUTOIDLE |
- OMAP2_MCSPI_SYSCONFIG_ENAWAKEUP |
- OMAP2_MCSPI_SYSCONFIG_SMARTIDLE);
-
- mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE,
- OMAP2_MCSPI_WAKEUPENABLE_WKEN);
+ tmp = OMAP2_MCSPI_SYSCONFIG_AUTOIDLE |
+ OMAP2_MCSPI_SYSCONFIG_ENAWAKEUP |
+ OMAP2_MCSPI_SYSCONFIG_SMARTIDLE;
+ mcspi_write_reg(master, OMAP2_MCSPI_SYSCONFIG, tmp);
+ omap2_mcspi_ctx[master->bus_num - 1].sysconfig = tmp;
+
+ tmp = OMAP2_MCSPI_WAKEUPENABLE_WKEN;
+ mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE, tmp);
+ omap2_mcspi_ctx[master->bus_num - 1].wakeupenable = tmp;
omap2_mcspi_set_master_mode(master);
-
- clk_disable(mcspi->fck);
- clk_disable(mcspi->ick);
+ omap2_mcspi_disable_clocks(mcspi);
return 0;
}
--
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