This patch series adds kernel support for StarFive hardware random
number generator. First 2 patches adds bindings documentations and
device driver for this module. Patch 3 adds devicetree entry for
VisionFive v2 SoC.
Patch 3 needs to be applied on top of:
https://patchwork.kernel.org/project/linux-riscv/patch/[email protected]/
Jia Jie Ho (3):
dt-bindings: rng: Add StarFive TRNG module
hwrng: starfive - Add TRNG driver for StarFive SoC
riscv: dts: starfive: Add TRNG node for VisionFive 2
.../bindings/rng/starfive,jh7110-trng.yaml | 55 +++
MAINTAINERS | 6 +
arch/riscv/boot/dts/starfive/jh7110.dtsi | 11 +
drivers/char/hw_random/Kconfig | 11 +
drivers/char/hw_random/Makefile | 1 +
drivers/char/hw_random/starfive-trng.c | 403 ++++++++++++++++++
6 files changed, 487 insertions(+)
create mode 100644 Documentation/devicetree/bindings/rng/starfive,jh7110-trng.yaml
create mode 100644 drivers/char/hw_random/starfive-trng.c
--
2.25.1
This adds driver support for the hardware random number generator in
Starfive SoCs and adds StarFive TRNG entry to MAINTAINERS.
Co-developed-by: Jenny Zhang <[email protected]>
Signed-off-by: Jenny Zhang <[email protected]>
Signed-off-by: Jia Jie Ho <[email protected]>
---
MAINTAINERS | 6 +
drivers/char/hw_random/Kconfig | 11 +
drivers/char/hw_random/Makefile | 1 +
drivers/char/hw_random/starfive-trng.c | 403 +++++++++++++++++++++++++
4 files changed, 421 insertions(+)
create mode 100644 drivers/char/hw_random/starfive-trng.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 65140500d9f8..b91e3fc11fc6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19626,6 +19626,12 @@ F: drivers/reset/reset-starfive.c
F: include/linux/reset/starfive.h
F: include/dt-bindings/reset/starfive*
+STARFIVE TRNG DRIVER
+M: Jia Jie Ho <[email protected]>
+S: Maintained
+F: Documentation/devicetree/bindings/rng/starfive*
+F: drivers/char/hw_random/starfive-trng.c
+
STATIC BRANCH/CALL
M: Peter Zijlstra <[email protected]>
M: Josh Poimboeuf <[email protected]>
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 3da8e85f8aae..ddd7ada7f877 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -549,6 +549,17 @@ config HW_RANDOM_CN10K
To compile this driver as a module, choose M here.
The module will be called cn10k_rng. If unsure, say Y.
+config HW_RANDOM_STARFIVE
+ tristate "StarFive HW Random Number Generator support"
+ depends on SOC_STARFIVE
+ depends on HW_RANDOM
+ help
+ This driver provides support for the Hardware Random Number
+ Generator in StarFive SoCs.
+
+ To compile this driver as a module, choose M here.
+ The module will be called starfive-trng.
+
endif # HW_RANDOM
config UML_RANDOM
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index 3e948cf04476..f68ac370847f 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -47,3 +47,4 @@ obj-$(CONFIG_HW_RANDOM_XIPHERA) += xiphera-trng.o
obj-$(CONFIG_HW_RANDOM_ARM_SMCCC_TRNG) += arm_smccc_trng.o
obj-$(CONFIG_HW_RANDOM_CN10K) += cn10k-rng.o
obj-$(CONFIG_HW_RANDOM_POLARFIRE_SOC) += mpfs-rng.o
+obj-$(CONFIG_HW_RANDOM_STARFIVE) += starfive-trng.o
diff --git a/drivers/char/hw_random/starfive-trng.c b/drivers/char/hw_random/starfive-trng.c
new file mode 100644
index 000000000000..ccb0be111177
--- /dev/null
+++ b/drivers/char/hw_random/starfive-trng.c
@@ -0,0 +1,403 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * TRNG driver for the StarFive SoC
+ *
+ * Copyright (C) 2022 StarFive Technology Co.
+ */
+
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/hw_random.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/random.h>
+#include <linux/reset.h>
+
+/* trng register offset */
+#define STARFIVE_CTRL 0x00
+#define STARFIVE_STAT 0x04
+#define STARFIVE_MODE 0x08
+#define STARFIVE_SMODE 0x0C
+#define STARFIVE_IE 0x10
+#define STARFIVE_ISTAT 0x14
+#define STARFIVE_RAND0 0x20
+#define STARFIVE_RAND1 0x24
+#define STARFIVE_RAND2 0x28
+#define STARFIVE_RAND3 0x2C
+#define STARFIVE_RAND4 0x30
+#define STARFIVE_RAND5 0x34
+#define STARFIVE_RAND6 0x38
+#define STARFIVE_RAND7 0x3C
+#define STARFIVE_AUTO_RQSTS 0x60
+#define STARFIVE_AUTO_AGE 0x64
+
+/* CTRL CMD */
+#define STARFIVE_CTRL_EXEC_NOP 0x0
+#define STARFIVE_CTRL_GENE_RANDNUM 0x1
+#define STARFIVE_CTRL_EXEC_RANDRESEED 0x2
+
+/* STAT */
+#define STARFIVE_STAT_NONCE_MODE BIT(2)
+#define STARFIVE_STAT_R256 BIT(3)
+#define STARFIVE_STAT_MISSION_MODE BIT(8)
+#define STARFIVE_STAT_SEEDED BIT(9)
+#define STARFIVE_STAT_LAST_RESEED(x) ((x) << 16)
+#define STARFIVE_STAT_SRVC_RQST BIT(27)
+#define STARFIVE_STAT_RAND_GENERATING BIT(30)
+#define STARFIVE_STAT_RAND_SEEDING BIT(31)
+
+/* MODE */
+#define STARFIVE_MODE_R256 BIT(3)
+
+/* SMODE */
+#define STARFIVE_SMODE_NONCE_MODE BIT(2)
+#define STARFIVE_SMODE_MISSION_MODE BIT(8)
+#define STARFIVE_SMODE_MAX_REJECTS(x) ((x) << 16)
+
+/* IE */
+#define STARFIVE_IE_RAND_RDY_EN BIT(0)
+#define STARFIVE_IE_SEED_DONE_EN BIT(1)
+#define STARFIVE_IE_LFSR_LOCKUP_EN BIT(4)
+#define STARFIVE_IE_GLBL_EN BIT(31)
+
+#define STARFIVE_IE_ALL (STARFIVE_IE_GLBL_EN | \
+ STARFIVE_IE_RAND_RDY_EN | \
+ STARFIVE_IE_SEED_DONE_EN | \
+ STARFIVE_IE_LFSR_LOCKUP_EN)
+
+/* ISTAT */
+#define STARFIVE_ISTAT_RAND_RDY BIT(0)
+#define STARFIVE_ISTAT_SEED_DONE BIT(1)
+#define STARFIVE_ISTAT_LFSR_LOCKUP BIT(4)
+
+#define STARFIVE_RAND_LEN sizeof(u32)
+
+#define to_trng(p) container_of(p, struct starfive_trng, rng)
+
+enum reseed {
+ RANDOM_RESEED,
+ NONCE_RESEED,
+};
+
+enum mode {
+ PRNG_128BIT,
+ PRNG_256BIT,
+};
+
+struct starfive_trng {
+ struct device *dev;
+ void __iomem *base;
+ struct clk *hclk;
+ struct clk *ahb;
+ struct reset_control *rst;
+ struct hwrng rng;
+ struct completion random_done;
+ struct completion reseed_done;
+ u32 mode;
+ u32 mission;
+ u32 reseed;
+};
+
+static u16 autoreq;
+module_param(autoreq, ushort, 0);
+MODULE_PARM_DESC(autoreq, "Auto-reseeding after random number requests by host reaches specified counter:\n"
+ " 0 - disable counter\n"
+ " other - reload value for internal counter");
+
+static u16 autoage;
+module_param(autoage, ushort, 0);
+MODULE_PARM_DESC(autoage, "Auto-reseeding after specified timer countdowns to 0:\n"
+ " 0 - disable timer\n"
+ " other - reload value for internal timer");
+
+static inline int starfive_trng_wait_idle(struct starfive_trng *trng)
+{
+ u32 stat;
+
+ return readl_relaxed_poll_timeout(trng->base + STARFIVE_STAT, stat,
+ !(stat & (STARFIVE_STAT_RAND_GENERATING |
+ STARFIVE_STAT_RAND_SEEDING)),
+ 10, 100000);
+}
+
+static inline void starfive_trng_irq_mask_clear(struct starfive_trng *trng)
+{
+ /* clear register: ISTAT */
+ u32 data = readl(trng->base + STARFIVE_ISTAT);
+
+ writel(data, trng->base + STARFIVE_ISTAT);
+}
+
+static int starfive_trng_cmd(struct starfive_trng *trng, u32 cmd)
+{
+ int ret;
+
+ ret = starfive_trng_wait_idle(trng);
+ if (ret)
+ return -ETIMEDOUT;
+
+ switch (cmd) {
+ case STARFIVE_CTRL_EXEC_NOP:
+ writel(cmd, trng->base + STARFIVE_CTRL);
+ break;
+ case STARFIVE_CTRL_GENE_RANDNUM:
+ reinit_completion(&trng->random_done);
+ writel(cmd, trng->base + STARFIVE_CTRL);
+ ret = wait_for_completion_timeout(&trng->random_done, 3000);
+ if (!ret)
+ return -ETIMEDOUT;
+ break;
+ case STARFIVE_CTRL_EXEC_RANDRESEED:
+ reinit_completion(&trng->reseed_done);
+ writel(cmd, trng->base + STARFIVE_CTRL);
+ ret = wait_for_completion_timeout(&trng->reseed_done, 3000);
+ if (!ret)
+ return -ETIMEDOUT;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int starfive_trng_init(struct hwrng *rng)
+{
+ struct starfive_trng *trng = to_trng(rng);
+ u32 mode, intr = 0;
+
+ /* disable Auto Request/Age register */
+ writel(autoage, trng->base + STARFIVE_AUTO_AGE);
+ writel(autoreq, trng->base + STARFIVE_AUTO_RQSTS);
+
+ /* clear register: ISTAT */
+ starfive_trng_irq_mask_clear(trng);
+
+ /* set smode/mode */
+ mode = readl(trng->base + STARFIVE_MODE);
+
+ switch (trng->mode) {
+ case PRNG_128BIT:
+ mode &= ~STARFIVE_MODE_R256;
+ break;
+ case PRNG_256BIT:
+ mode |= STARFIVE_MODE_R256;
+ break;
+ default:
+ mode |= STARFIVE_MODE_R256;
+ break;
+ }
+
+ intr |= STARFIVE_IE_ALL;
+ writel(intr, trng->base + STARFIVE_IE);
+ writel(mode, trng->base + STARFIVE_MODE);
+
+ starfive_trng_cmd(trng, STARFIVE_CTRL_EXEC_NOP);
+
+ return starfive_trng_cmd(trng, STARFIVE_CTRL_EXEC_RANDRESEED);
+}
+
+static irqreturn_t starfive_trng_irq(int irq, void *priv)
+{
+ u32 status;
+ struct starfive_trng *trng = (struct starfive_trng *)priv;
+
+ status = readl(trng->base + STARFIVE_ISTAT);
+ if (status & STARFIVE_ISTAT_RAND_RDY) {
+ writel(STARFIVE_ISTAT_RAND_RDY, trng->base + STARFIVE_ISTAT);
+ complete(&trng->random_done);
+ }
+
+ if (status & STARFIVE_ISTAT_SEED_DONE) {
+ writel(STARFIVE_ISTAT_SEED_DONE, trng->base + STARFIVE_ISTAT);
+ complete(&trng->reseed_done);
+ }
+
+ if (status & STARFIVE_ISTAT_LFSR_LOCKUP) {
+ writel(STARFIVE_ISTAT_LFSR_LOCKUP, trng->base + STARFIVE_ISTAT);
+ starfive_trng_cmd(trng, STARFIVE_CTRL_EXEC_RANDRESEED);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static void starfive_trng_cleanup(struct hwrng *rng)
+{
+ struct starfive_trng *trng = to_trng(rng);
+
+ writel(0, trng->base + STARFIVE_CTRL);
+
+ reset_control_assert(trng->rst);
+ clk_disable_unprepare(trng->hclk);
+ clk_disable_unprepare(trng->ahb);
+}
+
+static int starfive_trng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
+{
+ struct starfive_trng *trng = to_trng(rng);
+ int ret;
+
+ pm_runtime_get_sync(trng->dev);
+
+ if (trng->mode == PRNG_256BIT)
+ max = min_t(size_t, max, (STARFIVE_RAND_LEN * 8));
+ else
+ max = min_t(size_t, max, (STARFIVE_RAND_LEN * 4));
+
+ ret = starfive_trng_cmd(trng, STARFIVE_CTRL_GENE_RANDNUM);
+ if (ret)
+ return ret;
+
+ memcpy_fromio(buf, trng->base + STARFIVE_RAND0, max);
+
+ pm_runtime_put_sync(trng->dev);
+
+ return max;
+}
+
+static int starfive_trng_probe(struct platform_device *pdev)
+{
+ int ret;
+ int irq;
+ struct starfive_trng *trng;
+
+ trng = devm_kzalloc(&pdev->dev, sizeof(*trng), GFP_KERNEL);
+ if (!trng)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, trng);
+ trng->dev = &pdev->dev;
+
+ trng->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(trng->base))
+ return dev_err_probe(&pdev->dev, PTR_ERR(trng->base),
+ "Error remapping memory for platform device.\n");
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
+
+ ret = devm_request_irq(&pdev->dev, irq, starfive_trng_irq, 0, pdev->name,
+ (void *)trng);
+ if (ret)
+ return dev_err_probe(&pdev->dev, irq,
+ "Failed to register interrupt handler\n");
+
+ trng->hclk = devm_clk_get(&pdev->dev, "hclk");
+ if (IS_ERR(trng->hclk))
+ return dev_err_probe(&pdev->dev, PTR_ERR(trng->hclk),
+ "Error getting hardware reference clock\n");
+
+ trng->ahb = devm_clk_get(&pdev->dev, "ahb");
+ if (IS_ERR(trng->ahb))
+ return dev_err_probe(&pdev->dev, PTR_ERR(trng->ahb),
+ "Error getting ahb reference clock\n");
+
+ trng->rst = devm_reset_control_get_shared(&pdev->dev, NULL);
+ if (IS_ERR(trng->rst))
+ return dev_err_probe(&pdev->dev, PTR_ERR(trng->rst),
+ "Error getting hardware reset line\n");
+
+ clk_prepare_enable(trng->hclk);
+ clk_prepare_enable(trng->ahb);
+ reset_control_deassert(trng->rst);
+
+ init_completion(&trng->random_done);
+ init_completion(&trng->reseed_done);
+
+ trng->rng.name = dev_driver_string(&pdev->dev);
+ trng->rng.init = starfive_trng_init;
+ trng->rng.cleanup = starfive_trng_cleanup;
+ trng->rng.read = starfive_trng_read;
+
+ trng->mode = PRNG_256BIT;
+ trng->mission = 1;
+ trng->reseed = RANDOM_RESEED;
+
+ ret = devm_hwrng_register(&pdev->dev, &trng->rng);
+ if (ret) {
+ dev_err_probe(&pdev->dev, ret, "Failed to register hwrng\n");
+ goto err_fail_register;
+ }
+
+ pm_runtime_use_autosuspend(&pdev->dev);
+ pm_runtime_set_autosuspend_delay(&pdev->dev, 100);
+ pm_runtime_enable(&pdev->dev);
+
+ return 0;
+
+err_fail_register:
+ pm_runtime_disable(&pdev->dev);
+
+ reset_control_assert(trng->rst);
+ clk_disable_unprepare(trng->ahb);
+ clk_disable_unprepare(trng->hclk);
+
+ return ret;
+}
+
+#ifdef CONFIG_PM
+static int starfive_trng_runtime_suspend(struct device *dev)
+{
+ struct starfive_trng *trng = dev_get_drvdata(dev);
+
+ clk_disable_unprepare(trng->hclk);
+ clk_disable_unprepare(trng->ahb);
+
+ return 0;
+}
+
+static int starfive_trng_runtime_resume(struct device *dev)
+{
+ struct starfive_trng *trng = dev_get_drvdata(dev);
+
+ clk_prepare_enable(trng->hclk);
+ clk_prepare_enable(trng->ahb);
+
+ return 0;
+}
+
+static int starfive_trng_runtime_idle(struct device *dev)
+{
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_autosuspend(dev);
+
+ return 0;
+}
+#endif
+
+static const struct dev_pm_ops starfive_trng_pm_ops = {
+ SET_RUNTIME_PM_OPS(starfive_trng_runtime_suspend,
+ starfive_trng_runtime_resume,
+ starfive_trng_runtime_idle)
+ SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+ pm_runtime_force_resume)
+};
+
+static const struct of_device_id trng_dt_ids[] = {
+ { .compatible = "starfive,jh7110-trng" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, trng_dt_ids);
+
+static struct platform_driver starfive_trng_driver = {
+ .probe = starfive_trng_probe,
+ .driver = {
+ .name = "starfive-trng",
+ .pm = &starfive_trng_pm_ops,
+ .of_match_table = of_match_ptr(trng_dt_ids),
+ },
+};
+
+module_platform_driver(starfive_trng_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("StarFive True Random Number Generator");
--
2.25.1
On 21/12/2022 10:08, Jia Jie Ho wrote:
> This adds driver support for the hardware random number generator in
> Starfive SoCs and adds StarFive TRNG entry to MAINTAINERS.
>
> Co-developed-by: Jenny Zhang <[email protected]>
> Signed-off-by: Jenny Zhang <[email protected]>
> Signed-off-by: Jia Jie Ho <[email protected]>
> ---
> MAINTAINERS | 6 +
> drivers/char/hw_random/Kconfig | 11 +
> drivers/char/hw_random/Makefile | 1 +
> drivers/char/hw_random/starfive-trng.c | 403 +++++++++++++++++++++++++
> 4 files changed, 421 insertions(+)
> create mode 100644 drivers/char/hw_random/starfive-trng.c
>
(...)
> +static const struct of_device_id trng_dt_ids[] = {
> + { .compatible = "starfive,jh7110-trng" },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, trng_dt_ids);
> +
> +static struct platform_driver starfive_trng_driver = {
> + .probe = starfive_trng_probe,
> + .driver = {
> + .name = "starfive-trng",
> + .pm = &starfive_trng_pm_ops,
> + .of_match_table = of_match_ptr(trng_dt_ids),
of_match_ptr goes with __maybe_unused. You will have now warnings, so
please test more your patches (W=1, sparse, smatch).
Best regards,
Krzysztof
> -----Original Message-----
> From: Krzysztof Kozlowski <[email protected]>
> Sent: Wednesday, December 21, 2022 5:49 PM
> To: JiaJie Ho <[email protected]>; Olivia Mackall
> <[email protected]>; Herbert Xu <[email protected]>; Rob
> Herring <[email protected]>; Krzysztof Kozlowski
> <[email protected]>
> Cc: Emil Renner Berthing <[email protected]>; Conor Dooley
> <[email protected]>; [email protected];
> [email protected]; [email protected]; linux-
> [email protected]
> Subject: Re: [PATCH 2/3] hwrng: starfive - Add TRNG driver for StarFive SoC
>
> On 21/12/2022 10:08, Jia Jie Ho wrote:
> > This adds driver support for the hardware random number generator in
> > Starfive SoCs and adds StarFive TRNG entry to MAINTAINERS.
> >
> > Co-developed-by: Jenny Zhang <[email protected]>
> > Signed-off-by: Jenny Zhang <[email protected]>
> > Signed-off-by: Jia Jie Ho <[email protected]>
> > ---
> > MAINTAINERS | 6 +
> > drivers/char/hw_random/Kconfig | 11 +
> > drivers/char/hw_random/Makefile | 1 +
> > drivers/char/hw_random/starfive-trng.c | 403
> > +++++++++++++++++++++++++
> > 4 files changed, 421 insertions(+)
> > create mode 100644 drivers/char/hw_random/starfive-trng.c
> >
>
> (...)
>
> > +static const struct of_device_id trng_dt_ids[] = {
> > + { .compatible = "starfive,jh7110-trng" },
> > + { }
> > +};
> > +MODULE_DEVICE_TABLE(of, trng_dt_ids);
> > +
> > +static struct platform_driver starfive_trng_driver = {
> > + .probe = starfive_trng_probe,
> > + .driver = {
> > + .name = "starfive-trng",
> > + .pm = &starfive_trng_pm_ops,
> > + .of_match_table = of_match_ptr(trng_dt_ids),
>
> of_match_ptr goes with __maybe_unused. You will have now warnings, so
> please test more your patches (W=1, sparse, smatch).
>
Hi Krzysztof,
Thanks for reviewing this patch.
How do I properly handle __maybe_unused functions in this scenario?
Will it help if I add #define as follows:
#ifdef CONFIG_PM
#define STARFIVE_RNG_PM_OPS (&starfive_rng_pm_ops)
#else
#define STARFIVE_RNG_PM_OPS NULL
#endif
static struct platform_driver starfive_trng_driver = {
.probe = starfive_trng_probe,
.driver = {
.name = "starfive-trng",
.pm = STARFIVE_RNG_PM_OPS,
.of_match_table = of_match_ptr(trng_dt_ids),
},
};
I did build the patches with the tools mentioned but did not get warnings.
Do I need a specific version, or have I done something wrong?
make C=2 drivers/char/hw_random/
CHECK scripts/mod/empty.c
CALL scripts/checksyscalls.sh
CHECK arch/riscv/kernel/vdso/vgettimeofday.c
CHECK drivers/char/hw_random/core.c
CHECK drivers/char/hw_random/starfive-trng.c
Regards,
Jia Jie
On 22/12/2022 10:35, JiaJie Ho wrote:
>
>
>> -----Original Message-----
>> From: Krzysztof Kozlowski <[email protected]>
>> Sent: Wednesday, December 21, 2022 5:49 PM
>> To: JiaJie Ho <[email protected]>; Olivia Mackall
>> <[email protected]>; Herbert Xu <[email protected]>; Rob
>> Herring <[email protected]>; Krzysztof Kozlowski
>> <[email protected]>
>> Cc: Emil Renner Berthing <[email protected]>; Conor Dooley
>> <[email protected]>; [email protected];
>> [email protected]; [email protected]; linux-
>> [email protected]
>> Subject: Re: [PATCH 2/3] hwrng: starfive - Add TRNG driver for StarFive SoC
>>
>> On 21/12/2022 10:08, Jia Jie Ho wrote:
>>> This adds driver support for the hardware random number generator in
>>> Starfive SoCs and adds StarFive TRNG entry to MAINTAINERS.
>>>
>>> Co-developed-by: Jenny Zhang <[email protected]>
>>> Signed-off-by: Jenny Zhang <[email protected]>
>>> Signed-off-by: Jia Jie Ho <[email protected]>
>>> ---
>>> MAINTAINERS | 6 +
>>> drivers/char/hw_random/Kconfig | 11 +
>>> drivers/char/hw_random/Makefile | 1 +
>>> drivers/char/hw_random/starfive-trng.c | 403
>>> +++++++++++++++++++++++++
>>> 4 files changed, 421 insertions(+)
>>> create mode 100644 drivers/char/hw_random/starfive-trng.c
>>>
>>
>> (...)
>>
>>> +static const struct of_device_id trng_dt_ids[] = {
>>> + { .compatible = "starfive,jh7110-trng" },
>>> + { }
>>> +};
>>> +MODULE_DEVICE_TABLE(of, trng_dt_ids);
>>> +
>>> +static struct platform_driver starfive_trng_driver = {
>>> + .probe = starfive_trng_probe,
>>> + .driver = {
>>> + .name = "starfive-trng",
>>> + .pm = &starfive_trng_pm_ops,
>>> + .of_match_table = of_match_ptr(trng_dt_ids),
>>
>> of_match_ptr goes with __maybe_unused. You will have now warnings, so
>> please test more your patches (W=1, sparse, smatch).
>>
>
> Hi Krzysztof,
>
> Thanks for reviewing this patch.
> How do I properly handle __maybe_unused functions in this scenario?
The same as in other files. Use `git grep`
> Will it help if I add #define as follows:
>
> #ifdef CONFIG_PM
> #define STARFIVE_RNG_PM_OPS (&starfive_rng_pm_ops)
> #else
> #define STARFIVE_RNG_PM_OPS NULL
> #endif
I talked only about of_match_ptr(). This is not of_match_ptr and should
have its own syntax (pm_sleep_ptr + static DEFINE_SIMPLE_DEV_PM_OPS)
>
> static struct platform_driver starfive_trng_driver = {
> .probe = starfive_trng_probe,
> .driver = {
> .name = "starfive-trng",
> .pm = STARFIVE_RNG_PM_OPS,
> .of_match_table = of_match_ptr(trng_dt_ids),
> },
> };
>
> I did build the patches with the tools mentioned but did not get warnings.
> Do I need a specific version, or have I done something wrong?
You just need proper COMPILE_TEST config with OF disabled.
Best regards,
Krzysztof
> -----Original Message-----
> From: Krzysztof Kozlowski <[email protected]>
> Sent: Thursday, December 22, 2022 5:44 PM
> To: JiaJie Ho <[email protected]>; Olivia Mackall
> <[email protected]>; Herbert Xu <[email protected]>; Rob
> Herring <[email protected]>; Krzysztof Kozlowski
> <[email protected]>
> Cc: Emil Renner Berthing <[email protected]>; Conor Dooley
> <[email protected]>; [email protected];
> [email protected]; [email protected]; linux-
> [email protected]
> Subject: Re: [PATCH 2/3] hwrng: starfive - Add TRNG driver for StarFive SoC
>
> > How do I properly handle __maybe_unused functions in this scenario?
>
> The same as in other files. Use `git grep`
>
> > Will it help if I add #define as follows:
> >
> > #ifdef CONFIG_PM
> > #define STARFIVE_RNG_PM_OPS (&starfive_rng_pm_ops) #else #define
> > STARFIVE_RNG_PM_OPS NULL #endif
>
> I talked only about of_match_ptr(). This is not of_match_ptr and should have
> its own syntax (pm_sleep_ptr + static DEFINE_SIMPLE_DEV_PM_OPS)
>
> >
> > static struct platform_driver starfive_trng_driver = {
> > .probe = starfive_trng_probe,
> > .driver = {
> > .name = "starfive-trng",
> > .pm = STARFIVE_RNG_PM_OPS,
> > .of_match_table = of_match_ptr(trng_dt_ids),
> > },
> > };
> >
> > I did build the patches with the tools mentioned but did not get warnings.
> > Do I need a specific version, or have I done something wrong?
>
> You just need proper COMPILE_TEST config with OF disabled.
>
I'll update the patch accordingly.
Thanks again for the comments and suggestions.
Regards,
Jia Jie