[1/2] spi/pxa2xx-pci: Add common clock framework support in PCI glue layer

Commit Message

Chew Chiau Ee June 2, 2014, 7:46 p.m. UTC

From: Chew, Chiau Ee <[e-mail]>

SPI PXA2XX core layer has dependency on common clock framework
to obtain information on host supported clock rate. Thus, we
setup the clock device in the PCI glue layer to enable PCI mode
host pass in the clock rate information.

Signed-off-by: Chew, Chiau Ee <[e-mail]>
---
 drivers/spi/spi-pxa2xx-pci.c |   20 ++++++++++++++++++++
 1 files changed, 20 insertions(+), 0 deletions(-)

Comments

Mark Brown June 2, 2014, 12:46 p.m. UTC | #1

On Tue, Jun 03, 2014 at 03:46:18AM +0800, Chew Chiau Ee wrote:

> ---
>  drivers/spi/spi-pxa2xx-pci.c |   20 ++++++++++++++++++++
>  1 files changed, 20 insertions(+), 0 deletions(-)

> +	clk = clk_register_fixed_rate(&dev->dev, "spi_pxa2xx_clk", NULL,
> +					CLK_IS_ROOT, c->max_clk_rate);
> +	 if (IS_ERR(clk))
> +		return PTR_ERR(clk);

This is pretty much fine code wise but I'd expect to see some Kconfig
updates adding dependencies on the clock API - clk_register_fixed_rate()
is only provided if the fixed rate driver is present.  I'm also not
seeing any changes to unregister the fixed rate clock as the device is
removed.

Patch

diff --git a/drivers/spi/spi-pxa2xx-pci.c b/drivers/spi/spi-pxa2xx-pci.c
index c1865c9..11adc9b 100644
--- a/drivers/spi/spi-pxa2xx-pci.c
+++ b/drivers/spi/spi-pxa2xx-pci.c
@@ -7,6 +7,9 @@ 
 #include <linux/of_device.h>
 #include <linux/module.h>
 #include <linux/spi/pxa2xx_spi.h>
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
 
 enum {
 	PORT_CE4100,
@@ -21,6 +24,7 @@  struct pxa_spi_info {
 	int tx_chan_id;
 	int rx_slave_id;
 	int rx_chan_id;
+	unsigned long max_clk_rate;
 };
 
 static struct pxa_spi_info spi_info_configs[] = {
@@ -32,6 +36,7 @@  static struct pxa_spi_info spi_info_configs[] = {
 		.tx_chan_id = -1,
 		.rx_slave_id = -1,
 		.rx_chan_id = -1,
+		.max_clk_rate = 3686400,
 	},
 	[PORT_BYT] = {
 		.type = LPSS_SSP,
@@ -41,6 +46,7 @@  static struct pxa_spi_info spi_info_configs[] = {
 		.tx_chan_id = 0,
 		.rx_slave_id = 1,
 		.rx_chan_id = 1,
+		.max_clk_rate = 50000000,
 	},
 };
 
@@ -53,6 +59,7 @@  static int pxa2xx_spi_pci_probe(struct pci_dev *dev,
 	struct pxa2xx_spi_master spi_pdata;
 	struct ssp_device *ssp;
 	struct pxa_spi_info *c;
+	struct clk *clk;
 
 	ret = pcim_enable_device(dev);
 	if (ret)
@@ -84,6 +91,19 @@  static int pxa2xx_spi_pci_probe(struct pci_dev *dev,
 	ssp->port_id = (c->port_id >= 0) ? c->port_id : dev->devfn;
 	ssp->type = c->type;
 
+	clk = clk_register_fixed_rate(&dev->dev, "spi_pxa2xx_clk", NULL,
+					CLK_IS_ROOT, c->max_clk_rate);
+	 if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	clk_register_clkdev(clk, NULL, dev_name(&dev->dev));
+
+	ssp->clk = devm_clk_get(&dev->dev, NULL);
+	if (IS_ERR(ssp->clk)) {
+		dev_err(&dev->dev, "failed to get clock\n");
+		return PTR_ERR(ssp->clk);
+	}
+
 	memset(&pi, 0, sizeof(pi));
 	pi.parent = &dev->dev;
 	pi.name = "pxa2xx-spi";