@@ -109,6 +109,12 @@ int fsi_device_peek(struct fsi_device *dev, void *val)
return fsi_slave_read(dev->slave, addr, val, sizeof(uint32_t));
}
+unsigned long fsi_device_local_bus_frequency(struct fsi_device *dev)
+{
+ return dev->slave->master->clock_frequency / dev->slave->clock_div;
+}
+EXPORT_SYMBOL_GPL(fsi_device_local_bus_frequency);
+
static void fsi_device_release(struct device *_device)
{
struct fsi_device *device = to_fsi_dev(_device);
@@ -209,12 +215,12 @@ static inline uint32_t fsi_smode_sid(int x)
return (x & FSI_SMODE_SID_MASK) << FSI_SMODE_SID_SHIFT;
}
-static uint32_t fsi_slave_smode(int id, u8 t_senddly, u8 t_echodly)
+static uint32_t fsi_slave_smode(int id, int div, u8 t_senddly, u8 t_echodly)
{
return FSI_SMODE_WSC | FSI_SMODE_ECRC
| fsi_smode_sid(id)
| fsi_smode_echodly(t_echodly - 1) | fsi_smode_senddly(t_senddly - 1)
- | fsi_smode_lbcrr(0x8);
+ | fsi_smode_lbcrr(div - 1);
}
static int fsi_slave_set_smode(struct fsi_slave *slave, uint8_t id)
@@ -225,7 +231,8 @@ static int fsi_slave_set_smode(struct fsi_slave *slave, uint8_t id)
/* set our smode register with the slave ID field to 0; this enables
* extended slave addressing
*/
- smode = fsi_slave_smode(slave->id, slave->t_send_delay, slave->t_echo_delay);
+ smode = fsi_slave_smode(slave->id, slave->clock_div, slave->t_send_delay,
+ slave->t_echo_delay);
data = cpu_to_be32(smode);
return fsi_master_write(slave->master, slave->link, id, FSI_SLAVE_BASE + FSI_SMODE,
@@ -950,6 +957,7 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
struct fsi_slave *slave;
uint8_t crc;
__be32 data, llmode, slbus;
+ u32 clock;
int rc;
/* Currently, we only support single slaves on a link, and use the
@@ -1003,6 +1011,7 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
slave->dev.of_node = fsi_slave_find_of_node(master, link, id);
slave->dev.release = fsi_slave_release;
device_initialize(&slave->dev);
+ slave->clock_div = FSI_SMODE_LBCRR_DEFAULT;
slave->cfam_id = cfam_id;
slave->master = master;
slave->link = link;
@@ -1020,6 +1029,10 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
}
+ if (master->clock_frequency && !device_property_read_u32(&slave->dev, "clock-frequency",
+ &clock) && clock)
+ slave->clock_div = DIV_ROUND_UP(master->clock_frequency, clock);
+
slbus = cpu_to_be32(FSI_SLBUS_FORCE);
rc = fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SLBUS,
&slbus, sizeof(slbus));
@@ -1289,6 +1302,9 @@ int fsi_master_register(struct fsi_master *master)
if (!dev_name(&master->dev))
dev_set_name(&master->dev, "fsi%d", master->idx);
+ if (master->flags & FSI_MASTER_FLAG_SWCLOCK)
+ master->clock_frequency = 100000000; // POWER reference clock
+
master->dev.class = &fsi_master_class;
mutex_lock(&master->scan_lock);
@@ -121,6 +121,7 @@
struct fsi_master {
struct device dev;
+ unsigned long clock_frequency;
int idx;
int n_links;
int flags;
@@ -48,6 +48,7 @@
#define FSI_SMODE_SD_DEFAULT 16 /* Default send delay */
#define FSI_SMODE_LBCRR_SHIFT 8 /* Clk ratio shift */
#define FSI_SMODE_LBCRR_MASK 0xf /* Clk ratio mask */
+#define FSI_SMODE_LBCRR_DEFAULT 2 /* Default clk ratio */
/*
* SISS fields
@@ -104,6 +105,7 @@ struct fsi_slave {
int id; /* FSI address */
int link; /* FSI link# */
u32 cfam_id;
+ u32 clock_div;
int chip_id;
uint32_t size; /* size of slave address space */
u8 t_send_delay;
@@ -24,6 +24,7 @@ extern int fsi_device_read(struct fsi_device *dev, uint32_t addr,
extern int fsi_device_write(struct fsi_device *dev, uint32_t addr,
const void *val, size_t size);
extern int fsi_device_peek(struct fsi_device *dev, void *val);
+extern unsigned long fsi_device_local_bus_frequency(struct fsi_device *dev);
struct fsi_device_id {
u8 engine_type;
Instead of a hardcoded local bus clock divider, calculate the responder local bus frequency from the FSI bus frequency. This will allow FSI engine drivers to set and calculate their bus (I2C, SPI, etc) frequencies. Signed-off-by: Eddie James <eajames@linux.ibm.com> --- Changes since v2: - Use cfam clock-frequency property instead of hardcoded master local bus divider - Change default local bus clock divider from 8 to 2 drivers/fsi/fsi-core.c | 22 +++++++++++++++++++--- drivers/fsi/fsi-master.h | 1 + drivers/fsi/fsi-slave.h | 2 ++ include/linux/fsi.h | 1 + 4 files changed, 23 insertions(+), 3 deletions(-)