[PATCH v4 30/37] memory: tegra20-emc: Continue probing if timings are missing in device-tree

Dmitry Osipenko
2020-06-09T13:16:33Z

EMC driver will become mandatory after turning it into interconnect
provider because interconnect users, like display controller driver, will
fail to probe using newer device-trees that have interconnect properties.
Thus make EMC driver to probe even if timings are missing in device-tree.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
drivers/memory/tegra/tegra20-emc.c | 34 ++++++++++++++----------------
1 file changed, 16 insertions(+), 18 deletions(-)

diff --git a/drivers/memory/tegra/tegra20-emc.c b/drivers/memory/tegra/tegra20-emc.c
index 507065c2f452..6cd3d50145dc 100644
--- a/drivers/memory/tegra/tegra20-emc.c
+++ b/drivers/memory/tegra/tegra20-emc.c
@@ -386,6 +386,11 @@ tegra_emc_find_node_by_ram_code(struct device *dev)
u32 value, ram_code;
int err;

+ if (of_get_child_count(dev->of_node) == 0) {
+ dev_info(dev, "device-tree doesn't have memory timings\n");
+ return NULL;
+ }
+
if (!of_property_read_bool(dev->of_node, "nvidia,use-ram-code"))
return of_node_get(dev->of_node);

@@ -454,6 +459,9 @@ static long emc_round_rate(unsigned long rate,
struct tegra_emc *emc = arg;
unsigned int i;

+ if (!emc->num_timings)
+ return clk_get_rate(emc->clk);
+
min_rate = min(min_rate, emc->timings[emc->num_timings - 1].rate);

for (i = 0; i < emc->num_timings; i++) {
@@ -691,13 +699,6 @@ static int tegra_emc_probe(struct platform_device *pdev)
struct tegra_emc *emc;
int irq, err;

- /* driver has nothing to do in a case of memory timing absence */
- if (of_get_child_count(pdev->dev.of_node) == 0) {
- dev_info(&pdev->dev,
- "EMC device tree node doesn't have memory timings\n");
- return 0;
- }
-
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "interrupt not specified\n");
@@ -705,23 +706,20 @@ static int tegra_emc_probe(struct platform_device *pdev)
return irq;
}

- np = tegra_emc_find_node_by_ram_code(&pdev->dev);
- if (!np)
- return -EINVAL;
-
emc = devm_kzalloc(&pdev->dev, sizeof(*emc), GFP_KERNEL);
- if (!emc) {
- of_node_put(np);
+ if (!emc)
return -ENOMEM;
- }

emc->clk_nb.notifier_call = tegra_emc_clk_change_notify;
emc->dev = &pdev->dev;

- err = tegra_emc_load_timings_from_dt(emc, np);
- of_node_put(np);
- if (err)
- return err;
+ np = tegra_emc_find_node_by_ram_code(&pdev->dev);
+ if (np) {
+ err = tegra_emc_load_timings_from_dt(emc, np);
+ of_node_put(np);
+ if (err)
+ return err;
+ }

emc->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(emc->regs))
--
2.26.0