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authorEugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>2017-12-28 15:09:03 +0300
committerJagan Teki <jagan@amarulasolutions.com>2018-01-26 11:26:16 +0530
commit58c125b9e2b232ce73ed7b24ba7b1ca5ff41c5bd (patch)
tree981b8163fb8e6208b30e808068033352927164ca /drivers/spi
parent21143ce127b953356bd6174fb4e4892af3a92d0f (diff)
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DW SPI: Get clock value from Device Tree
Add option to set spi controller clock frequency via device tree using standard clock bindings. Define dw_spi_get_clk function as 'weak' as some targets (like SOCFPGA_GEN5 and SOCFPGA_ARRIA10) don't use standard clock API and implement dw_spi_get_clk their own way in their clock manager. Get rid of clock_manager.h include as we don't use cm_get_spi_controller_clk_hz function anymore. (we use redefined dw_spi_get_clk in SOCFPGA clock managers instead) Reviewed-by: Marek Vasut <marex@denx.de> Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Reviewed-by: Jagan Teki <jagan@openedev.com>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/designware_spi.c45
1 files changed, 43 insertions, 2 deletions
diff --git a/drivers/spi/designware_spi.c b/drivers/spi/designware_spi.c
index 5aa507b..c501aee 100644
--- a/drivers/spi/designware_spi.c
+++ b/drivers/spi/designware_spi.c
@@ -11,6 +11,7 @@
*/
#include <common.h>
+#include <clk.h>
#include <dm.h>
#include <errno.h>
#include <malloc.h>
@@ -18,7 +19,6 @@
#include <fdtdec.h>
#include <linux/compat.h>
#include <asm/io.h>
-#include <asm/arch/clock_manager.h>
DECLARE_GLOBAL_DATA_PTR;
@@ -94,6 +94,8 @@ struct dw_spi_priv {
void __iomem *regs;
unsigned int freq; /* Default frequency */
unsigned int mode;
+ struct clk clk;
+ unsigned long bus_clk_rate;
int bits_per_word;
u8 cs; /* chip select pin */
@@ -176,14 +178,53 @@ static void spi_hw_init(struct dw_spi_priv *priv)
debug("%s: fifo_len=%d\n", __func__, priv->fifo_len);
}
+/*
+ * We define dw_spi_get_clk function as 'weak' as some targets
+ * (like SOCFPGA_GEN5 and SOCFPGA_ARRIA10) don't use standard clock API
+ * and implement dw_spi_get_clk their own way in their clock manager.
+ */
+__weak int dw_spi_get_clk(struct udevice *bus, ulong *rate)
+{
+ struct dw_spi_priv *priv = dev_get_priv(bus);
+ int ret;
+
+ ret = clk_get_by_index(bus, 0, &priv->clk);
+ if (ret)
+ return ret;
+
+ ret = clk_enable(&priv->clk);
+ if (ret && ret != -ENOSYS && ret != -ENOTSUPP)
+ return ret;
+
+ *rate = clk_get_rate(&priv->clk);
+ if (!*rate)
+ goto err_rate;
+
+ debug("%s: get spi controller clk via device tree: %lu Hz\n",
+ __func__, *rate);
+
+ return 0;
+
+err_rate:
+ clk_disable(&priv->clk);
+ clk_free(&priv->clk);
+
+ return -EINVAL;
+}
+
static int dw_spi_probe(struct udevice *bus)
{
struct dw_spi_platdata *plat = dev_get_platdata(bus);
struct dw_spi_priv *priv = dev_get_priv(bus);
+ int ret;
priv->regs = plat->regs;
priv->freq = plat->frequency;
+ ret = dw_spi_get_clk(bus, &priv->bus_clk_rate);
+ if (ret)
+ return ret;
+
/* Currently only bits_per_word == 8 supported */
priv->bits_per_word = 8;
@@ -369,7 +410,7 @@ static int dw_spi_set_speed(struct udevice *bus, uint speed)
spi_enable_chip(priv, 0);
/* clk_div doesn't support odd number */
- clk_div = cm_get_spi_controller_clk_hz() / speed;
+ clk_div = priv->bus_clk_rate / speed;
clk_div = (clk_div + 1) & 0xfffe;
dw_writel(priv, DW_SPI_BAUDR, clk_div);