Use clock freqency from the device tree to calculate correct MPC5200 PSC clock.
Previous code had errors or used a constant. This versions computes
the right clock based on the xtal and register settings.
---
arch/powerpc/include/asm/mpc52xx.h |2 +-
arch/powerpc/platforms/52xx/mpc52xx_common.c | 26 --
drivers/spi/mpc52xx_psc_spi.c|8 +---
sound/soc/fsl/mpc5200_psc_i2s.c | 11 +--
4 files changed, 27 insertions(+), 20 deletions(-)
diff --git a/arch/powerpc/include/asm/mpc52xx.h
b/arch/powerpc/include/asm/mpc52xx.h
index cadd398..1ca8a0e 100644
--- a/arch/powerpc/include/asm/mpc52xx.h
+++ b/arch/powerpc/include/asm/mpc52xx.h
@@ -285,7 +285,7 @@ struct mpc52xx_rtc {
extern void mpc5200_setup_xlb_arbiter(void);
extern void mpc52xx_declare_of_platform_devices(void);
extern void mpc52xx_map_common_devices(void);
-extern int mpc52xx_set_psc_clkdiv(int psc_id, int clkdiv);
+extern int mpc52xx_set_psc_clkdiv(int psc_id, int freq);
extern unsigned int mpc52xx_get_xtal_freq(struct device_node *node);
extern void mpc52xx_restart(char *cmd);
diff --git a/arch/powerpc/platforms/52xx/mpc52xx_common.c
b/arch/powerpc/platforms/52xx/mpc52xx_common.c
index a46bad0..f81fb03 100644
--- a/arch/powerpc/platforms/52xx/mpc52xx_common.c
+++ b/arch/powerpc/platforms/52xx/mpc52xx_common.c
@@ -110,6 +110,8 @@ static struct of_device_id mpc52xx_cdm_ids[] __initdata = {
{}
};
+static u32 fsystem; /* fsystem clock on mpc5200 */
+
/**
* mpc52xx_map_common_devices: iomap devices required by common code
*/
@@ -117,6 +119,7 @@ void __init
mpc52xx_map_common_devices(void)
{
struct device_node *np;
+ u32 val;
/* mpc52xx_wdt is mapped here and used in mpc52xx_restart,
* possibly from a interrupt context. wdt is only implement
@@ -133,8 +136,16 @@ mpc52xx_map_common_devices(void)
/* Clock Distribution Module, used by PSC clock setting function */
np = of_find_matching_node(NULL, mpc52xx_cdm_ids);
+ fsystem = mpc5xxx_get_bus_frequency(np);
mpc52xx_cdm = of_iomap(np, 0);
of_node_put(np);
+
+ /* compute fsystem, it is either 4 or 8 times the bus freq */
+ val = in_be32(mpc52xx_cdm-rstcfg);
+ if (val (1 5))
+ fsystem *= 8;
+ else
+ fsystem *= 4;
}
/**
@@ -143,17 +154,28 @@ mpc52xx_map_common_devices(void)
* @psc_id: id of psc port; must be 1,2,3 or 6
* @clkdiv: clock divider value to put into CDM PSC register.
*/
-int mpc52xx_set_psc_clkdiv(int psc_id, int clkdiv)
+int mpc52xx_set_psc_clkdiv(int psc_id, int freq)
{
unsigned long flags;
u16 __iomem *reg;
u32 val;
- u32 mask;
+ u32 mask, clkdiv, err;
u32 mclken_div;
if (!mpc52xx_cdm)
return -ENODEV;
+ /* figure out the closest frequency the hardware can make */
+ clkdiv = fsystem / freq;
+ err = fsystem % freq;
+ if (err freq / 2)
+ clkdiv++;
+ /* hardware is not very flexible, there will be significant error */
+ /* frequency error = fsystem / clkdiv - freq; */
+
+ /* hardware adds one to the divisor */
+ clkdiv -= 1;
+
mclken_div = 0x8000 | (clkdiv 0x1FF);
switch (psc_id) {
case 1: reg = mpc52xx_cdm-mclken_div_psc1; mask = 0x20; break;
diff --git a/drivers/spi/mpc52xx_psc_spi.c b/drivers/spi/mpc52xx_psc_spi.c
index d2a04d6..5c8e621 100644
--- a/drivers/spi/mpc52xx_psc_spi.c
+++ b/drivers/spi/mpc52xx_psc_spi.c
@@ -33,7 +33,6 @@
struct mpc52xx_psc_spi {
/* fsl_spi_platform data */
void (*cs_control)(struct spi_device *spi, bool on);
- u32 sysclk;
/* driver internal data */
struct mpc52xx_psc __iomem *psc;
@@ -313,12 +312,9 @@ static int mpc52xx_psc_spi_port_config(int psc_id, struct
mpc52xx_psc_spi *mps)
{
struct mpc52xx_psc __iomem *psc = mps-psc;
struct mpc52xx_psc_fifo __iomem *fifo = mps-fifo;
- u32 mclken_div;
int ret = 0;
- /* default sysclk is 512MHz */
- mclken_div = (mps-sysclk ? mps-sysclk : 51200) / MCLK;
- mpc52xx_set_psc_clkdiv(psc_id, mclken_div);
+ mpc52xx_set_psc_clkdiv(psc_id, MCLK);
/* Reset the PSC into a known state */
out_8(psc-command, MPC52xx_PSC_RST_RX);
@@ -383,12 +379,10 @@ static int __init mpc52xx_psc_spi_do_probe(struct
of_device *op, u32 regaddr,
dev_warn(op-dev, probe called without platform data, no
cs_control function will be called\n);
mps-cs_control = NULL;
- mps-sysclk = 0;
master-bus_num = bus_num;
master-num_chipselect = 255;
} else {
mps-cs_control = pdata-cs_control;
- mps-sysclk = pdata-sysclk;
master-bus_num = pdata-bus_num;
master-num_chipselect =
