[PATCH v4 01/10] memory: ti-aemif: Store timings parameter in number of cycles - 1
Bastien Curutchet
bastien.curutchet at bootlin.com
Fri Nov 15 05:26:22 PST 2024
The CS configuration register expects timings to be expressed in
'number of cycles - 1' but they are stored in ns in the struct
aemif_cs_data. So at init, the timings currently set are converted to ns
by aemif_get_hw_params(), updated with values from the device-tree
properties, and then converted back to 'number of cycles - 1' before
being applied.
Store the timings directly in 'number of cycles - 1' instead of
nanoseconds.
Perform the conversion from nanosecond during the device-tree parsing.
Remove aemif_cycles_to_nsec() as it isn't used anymore.
Signed-off-by: Bastien Curutchet <bastien.curutchet at bootlin.com>
---
drivers/memory/ti-aemif.c | 137 ++++++++++++++++++++++----------------
1 file changed, 80 insertions(+), 57 deletions(-)
diff --git a/drivers/memory/ti-aemif.c b/drivers/memory/ti-aemif.c
index d54dc3cfff73..bd0c49ba1939 100644
--- a/drivers/memory/ti-aemif.c
+++ b/drivers/memory/ti-aemif.c
@@ -80,28 +80,28 @@
ASIZE_MAX)
/**
- * struct aemif_cs_data: structure to hold cs parameters
+ * struct aemif_cs_data: structure to hold CS parameters
* @cs: chip-select number
- * @wstrobe: write strobe width, ns
- * @rstrobe: read strobe width, ns
- * @wsetup: write setup width, ns
- * @whold: write hold width, ns
- * @rsetup: read setup width, ns
- * @rhold: read hold width, ns
- * @ta: minimum turn around time, ns
+ * @wstrobe: write strobe width, number of cycles - 1
+ * @rstrobe: read strobe width, number of cycles - 1
+ * @wsetup: write setup width, number of cycles - 1
+ * @whold: write hold width, number of cycles - 1
+ * @rsetup: read setup width, number of cycles - 1
+ * @rhold: read hold width, number of cycles - 1
+ * @ta: minimum turn around time, number of cycles - 1
* @enable_ss: enable/disable select strobe mode
* @enable_ew: enable/disable extended wait mode
* @asize: width of the asynchronous device's data bus
*/
struct aemif_cs_data {
u8 cs;
- u16 wstrobe;
- u16 rstrobe;
- u8 wsetup;
- u8 whold;
- u8 rsetup;
- u8 rhold;
- u8 ta;
+ u32 wstrobe;
+ u32 rstrobe;
+ u32 wsetup;
+ u32 whold;
+ u32 rsetup;
+ u32 rhold;
+ u32 ta;
u8 enable_ss;
u8 enable_ew;
u8 asize;
@@ -175,26 +175,18 @@ static int aemif_config_abus(struct platform_device *pdev, int csnum)
struct aemif_device *aemif = platform_get_drvdata(pdev);
struct aemif_cs_data *data = &aemif->cs_data[csnum];
int ta, rhold, rstrobe, rsetup, whold, wstrobe, wsetup;
- unsigned long clk_rate = aemif->clk_rate;
unsigned offset;
u32 set, val;
offset = A1CR_OFFSET + (data->cs - aemif->cs_offset) * 4;
- ta = aemif_calc_rate(pdev, data->ta, clk_rate, TA_MAX);
- rhold = aemif_calc_rate(pdev, data->rhold, clk_rate, RHOLD_MAX);
- rstrobe = aemif_calc_rate(pdev, data->rstrobe, clk_rate, RSTROBE_MAX);
- rsetup = aemif_calc_rate(pdev, data->rsetup, clk_rate, RSETUP_MAX);
- whold = aemif_calc_rate(pdev, data->whold, clk_rate, WHOLD_MAX);
- wstrobe = aemif_calc_rate(pdev, data->wstrobe, clk_rate, WSTROBE_MAX);
- wsetup = aemif_calc_rate(pdev, data->wsetup, clk_rate, WSETUP_MAX);
-
- if (ta < 0 || rhold < 0 || rstrobe < 0 || rsetup < 0 ||
- whold < 0 || wstrobe < 0 || wsetup < 0) {
- dev_err(&pdev->dev, "%s: cannot get suitable timings\n",
- __func__);
- return -EINVAL;
- }
+ ta = data->ta;
+ rhold = data->rhold;
+ rstrobe = data->rstrobe;
+ rsetup = data->rsetup;
+ whold = data->whold;
+ wstrobe = data->wstrobe;
+ wsetup = data->wsetup;
set = TA(ta) | RHOLD(rhold) | RSTROBE(rstrobe) | RSETUP(rsetup) |
WHOLD(whold) | WSTROBE(wstrobe) | WSETUP(wsetup);
@@ -213,11 +205,6 @@ static int aemif_config_abus(struct platform_device *pdev, int csnum)
return 0;
}
-static inline int aemif_cycles_to_nsec(int val, unsigned long clk_rate)
-{
- return ((val + 1) * NSEC_PER_MSEC) / clk_rate;
-}
-
/**
* aemif_get_hw_params - function to read hw register values
* @pdev: platform device to read for
@@ -231,19 +218,18 @@ static void aemif_get_hw_params(struct platform_device *pdev, int csnum)
{
struct aemif_device *aemif = platform_get_drvdata(pdev);
struct aemif_cs_data *data = &aemif->cs_data[csnum];
- unsigned long clk_rate = aemif->clk_rate;
u32 val, offset;
offset = A1CR_OFFSET + (data->cs - aemif->cs_offset) * 4;
val = readl(aemif->base + offset);
- data->ta = aemif_cycles_to_nsec(TA_VAL(val), clk_rate);
- data->rhold = aemif_cycles_to_nsec(RHOLD_VAL(val), clk_rate);
- data->rstrobe = aemif_cycles_to_nsec(RSTROBE_VAL(val), clk_rate);
- data->rsetup = aemif_cycles_to_nsec(RSETUP_VAL(val), clk_rate);
- data->whold = aemif_cycles_to_nsec(WHOLD_VAL(val), clk_rate);
- data->wstrobe = aemif_cycles_to_nsec(WSTROBE_VAL(val), clk_rate);
- data->wsetup = aemif_cycles_to_nsec(WSETUP_VAL(val), clk_rate);
+ data->ta = TA_VAL(val);
+ data->rhold = RHOLD_VAL(val);
+ data->rstrobe = RSTROBE_VAL(val);
+ data->rsetup = RSETUP_VAL(val);
+ data->whold = WHOLD_VAL(val);
+ data->wstrobe = WSTROBE_VAL(val);
+ data->wsetup = WSETUP_VAL(val);
data->enable_ew = EW_VAL(val);
data->enable_ss = SSTROBE_VAL(val);
data->asize = val & ASIZE_MAX;
@@ -261,7 +247,9 @@ static int of_aemif_parse_abus_config(struct platform_device *pdev,
struct device_node *np)
{
struct aemif_device *aemif = platform_get_drvdata(pdev);
+ unsigned long clk_rate = aemif->clk_rate;
struct aemif_cs_data *data;
+ int ret;
u32 cs;
u32 val;
@@ -287,26 +275,61 @@ static int of_aemif_parse_abus_config(struct platform_device *pdev,
aemif_get_hw_params(pdev, aemif->num_cs++);
/* override the values from device node */
- if (!of_property_read_u32(np, "ti,cs-min-turnaround-ns", &val))
- data->ta = val;
+ if (!of_property_read_u32(np, "ti,cs-min-turnaround-ns", &val)) {
+ ret = aemif_calc_rate(pdev, val, clk_rate, TA_MAX);
+ if (ret < 0)
+ return ret;
- if (!of_property_read_u32(np, "ti,cs-read-hold-ns", &val))
- data->rhold = val;
+ data->ta = ret;
+ }
- if (!of_property_read_u32(np, "ti,cs-read-strobe-ns", &val))
- data->rstrobe = val;
+ if (!of_property_read_u32(np, "ti,cs-read-hold-ns", &val)) {
+ ret = aemif_calc_rate(pdev, val, clk_rate, RHOLD_MAX);
+ if (ret < 0)
+ return ret;
- if (!of_property_read_u32(np, "ti,cs-read-setup-ns", &val))
- data->rsetup = val;
+ data->rhold = ret;
+ }
- if (!of_property_read_u32(np, "ti,cs-write-hold-ns", &val))
- data->whold = val;
+ if (!of_property_read_u32(np, "ti,cs-read-strobe-ns", &val)) {
+ ret = aemif_calc_rate(pdev, val, clk_rate, RSTROBE_MAX);
+ if (ret < 0)
+ return ret;
- if (!of_property_read_u32(np, "ti,cs-write-strobe-ns", &val))
- data->wstrobe = val;
+ data->rstrobe = ret;
+ }
- if (!of_property_read_u32(np, "ti,cs-write-setup-ns", &val))
- data->wsetup = val;
+ if (!of_property_read_u32(np, "ti,cs-read-setup-ns", &val)) {
+ ret = aemif_calc_rate(pdev, val, clk_rate, RSETUP_MAX);
+ if (ret < 0)
+ return ret;
+
+ data->rsetup = ret;
+ }
+
+ if (!of_property_read_u32(np, "ti,cs-write-hold-ns", &val)) {
+ ret = aemif_calc_rate(pdev, val, clk_rate, WHOLD_MAX);
+ if (ret < 0)
+ return ret;
+
+ data->whold = ret;
+ }
+
+ if (!of_property_read_u32(np, "ti,cs-write-strobe-ns", &val)) {
+ ret = aemif_calc_rate(pdev, val, clk_rate, WSTROBE_MAX);
+ if (ret < 0)
+ return ret;
+
+ data->wstrobe = ret;
+ }
+
+ if (!of_property_read_u32(np, "ti,cs-write-setup-ns", &val)) {
+ ret = aemif_calc_rate(pdev, val, clk_rate, WSETUP_MAX);
+ if (ret < 0)
+ return ret;
+
+ data->wsetup = ret;
+ }
if (!of_property_read_u32(np, "ti,cs-bus-width", &val))
if (val == 16)
--
2.47.0
More information about the linux-mtd
mailing list