diff mbox series

[RESEND,v3,11/11] clk: stm32mp1: new compatible for secure RCC support

Message ID 20210617051814.12018-12-gabriel.fernandez@foss.st.com (mailing list archive)
State Accepted, archived
Headers show
Series Introduce STM32MP1 RCC in secured mode | expand

Commit Message

Gabriel FERNANDEZ June 17, 2021, 5:18 a.m. UTC 
From: Gabriel Fernandez <gabriel.fernandez@foss.st.com>

Platform STM32MP1 can be used in configuration where some clock
resources cannot be accessed by Linux kernel when executing in non-secure
state of the CPU(s).
In such configuration, the RCC clock driver must not register clocks
it cannot access.
They are expected to be registered from another clock driver such
as the SCMI clock driver.
This change uses specific compatible string "st,stm32mp1-rcc-secure"
to specify RCC clock driver configuration where RCC is secure.

Signed-off-by: Etienne Carriere <etienne.carriere@foss.st.com>
Signed-off-by: Gabriel Fernandez <gabriel.fernandez@foss.st.com>
---
 drivers/clk/Kconfig        |  10 ++++
 drivers/clk/clk-stm32mp1.c | 101 ++++++++++++++++++++++++++++++++++++-
 2 files changed, 110 insertions(+), 1 deletion(-)

Comments

Marek Vasut June 17, 2021, 6:46 a.m. UTC | #1 
On 6/17/21 7:18 AM, gabriel.fernandez@foss.st.com wrote:
> From: Gabriel Fernandez <gabriel.fernandez@foss.st.com>
> 
> Platform STM32MP1 can be used in configuration where some clock
> resources cannot be accessed by Linux kernel when executing in non-secure
> state of the CPU(s).
> In such configuration, the RCC clock driver must not register clocks
> it cannot access.
> They are expected to be registered from another clock driver such
> as the SCMI clock driver.
> This change uses specific compatible string "st,stm32mp1-rcc-secure"
> to specify RCC clock driver configuration where RCC is secure.

Should this really be a new compatible string or rather a DT property ? 
I think the later, since this is the same clock IP, only operating in 
different "mode" , no ?
Gabriel FERNANDEZ June 18, 2021, 1:24 p.m. UTC | #2 
Yes we could have considered it as a feature but we think it's better to 
manage it as a layer of our driver via a compatible.

On 6/17/21 8:46 AM, Marek Vasut wrote:
> On 6/17/21 7:18 AM, gabriel.fernandez@foss.st.com wrote:
>> From: Gabriel Fernandez <gabriel.fernandez@foss.st.com>
>>
>> Platform STM32MP1 can be used in configuration where some clock
>> resources cannot be accessed by Linux kernel when executing in non-secure
>> state of the CPU(s).
>> In such configuration, the RCC clock driver must not register clocks
>> it cannot access.
>> They are expected to be registered from another clock driver such
>> as the SCMI clock driver.
>> This change uses specific compatible string "st,stm32mp1-rcc-secure"
>> to specify RCC clock driver configuration where RCC is secure.
> 
> Should this really be a new compatible string or rather a DT property ? 
> I think the later, since this is the same clock IP, only operating in 
> different "mode" , no ?
Stephen Boyd June 28, 2021, 1:36 a.m. UTC | #3 
Quoting gabriel.fernandez@foss.st.com (2021-06-16 22:18:14)
> From: Gabriel Fernandez <gabriel.fernandez@foss.st.com>
> 
> Platform STM32MP1 can be used in configuration where some clock
> resources cannot be accessed by Linux kernel when executing in non-secure
> state of the CPU(s).
> In such configuration, the RCC clock driver must not register clocks
> it cannot access.
> They are expected to be registered from another clock driver such
> as the SCMI clock driver.
> This change uses specific compatible string "st,stm32mp1-rcc-secure"
> to specify RCC clock driver configuration where RCC is secure.
> 
> Signed-off-by: Etienne Carriere <etienne.carriere@foss.st.com>
> Signed-off-by: Gabriel Fernandez <gabriel.fernandez@foss.st.com>
> ---

Applied to clk-next
diff mbox series

Patch

diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index e80918be8e9c..e367a033e121 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -335,6 +335,16 @@  config COMMON_CLK_STM32MP157
 	help
 	  Support for stm32mp157 SoC family clocks
 
+config COMMON_CLK_STM32MP157_SCMI
+	bool "stm32mp157 Clock driver with Trusted Firmware"
+	depends on COMMON_CLK_STM32MP157
+	select COMMON_CLK_SCMI
+	select ARM_SCMI_PROTOCOL
+	default y
+	help
+	  Support for stm32mp157 SoC family clocks with Trusted Firmware using
+	  SCMI protocol.
+
 config COMMON_CLK_STM32F
 	def_bool COMMON_CLK && (MACH_STM32F429 || MACH_STM32F469 || MACH_STM32F746)
 	help
diff --git a/drivers/clk/clk-stm32mp1.c b/drivers/clk/clk-stm32mp1.c
index 6d3a36f81b2d..6adc625e79cb 100644
--- a/drivers/clk/clk-stm32mp1.c
+++ b/drivers/clk/clk-stm32mp1.c
@@ -2056,11 +2056,61 @@  static const struct clock_config stm32mp1_clock_cfg[] = {
 		  _DIV(RCC_DBGCFGR, 0, 3, 0, ck_trace_div_table)),
 };
 
+static const u32 stm32mp1_clock_secured[] = {
+	CK_HSE,
+	CK_HSI,
+	CK_CSI,
+	CK_LSI,
+	CK_LSE,
+	PLL1,
+	PLL2,
+	PLL1_P,
+	PLL2_P,
+	PLL2_Q,
+	PLL2_R,
+	CK_MPU,
+	CK_AXI,
+	SPI6,
+	I2C4,
+	I2C6,
+	USART1,
+	RTCAPB,
+	TZC1,
+	TZC2,
+	TZPC,
+	IWDG1,
+	BSEC,
+	STGEN,
+	GPIOZ,
+	CRYP1,
+	HASH1,
+	RNG1,
+	BKPSRAM,
+	RNG1_K,
+	STGEN_K,
+	SPI6_K,
+	I2C4_K,
+	I2C6_K,
+	USART1_K,
+	RTC,
+};
+
+static bool stm32_check_security(const struct clock_config *cfg)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(stm32mp1_clock_secured); i++)
+		if (cfg->id == stm32mp1_clock_secured[i])
+			return true;
+	return false;
+}
+
 struct stm32_rcc_match_data {
 	const struct clock_config *cfg;
 	unsigned int num;
 	unsigned int maxbinding;
 	u32 clear_offset;
+	bool (*check_security)(const struct clock_config *cfg);
 };
 
 static struct stm32_rcc_match_data stm32mp1_data = {
@@ -2070,11 +2120,23 @@  static struct stm32_rcc_match_data stm32mp1_data = {
 	.clear_offset	= RCC_CLR,
 };
 
+static struct stm32_rcc_match_data stm32mp1_data_secure = {
+	.cfg		= stm32mp1_clock_cfg,
+	.num		= ARRAY_SIZE(stm32mp1_clock_cfg),
+	.maxbinding	= STM32MP1_LAST_CLK,
+	.clear_offset	= RCC_CLR,
+	.check_security = &stm32_check_security
+};
+
 static const struct of_device_id stm32mp1_match_data[] = {
 	{
 		.compatible = "st,stm32mp1-rcc",
 		.data = &stm32mp1_data,
 	},
+	{
+		.compatible = "st,stm32mp1-rcc-secure",
+		.data = &stm32mp1_data_secure,
+	},
 	{ }
 };
 MODULE_DEVICE_TABLE(of, stm32mp1_match_data);
@@ -2234,6 +2296,9 @@  static int stm32_rcc_clock_init(struct device *dev, void __iomem *base,
 		hws[n] = ERR_PTR(-ENOENT);
 
 	for (n = 0; n < data->num; n++) {
+		if (data->check_security && data->check_security(&data->cfg[n]))
+			continue;
+
 		err = stm32_register_hw_clk(dev, clk_data, base, &rlock,
 					    &data->cfg[n]);
 		if (err) {
@@ -2301,11 +2366,45 @@  static int stm32mp1_rcc_init(struct device *dev)
 	return ret;
 }
 
+static int get_clock_deps(struct device *dev)
+{
+	static const char * const clock_deps_name[] = {
+		"hsi", "hse", "csi", "lsi", "lse",
+	};
+	size_t deps_size = sizeof(struct clk *) * ARRAY_SIZE(clock_deps_name);
+	struct clk **clk_deps;
+	int i;
+
+	clk_deps = devm_kzalloc(dev, deps_size, GFP_KERNEL);
+	if (!clk_deps)
+		return -ENOMEM;
+
+	for (i = 0; i < ARRAY_SIZE(clock_deps_name); i++) {
+		struct clk *clk = of_clk_get_by_name(dev_of_node(dev),
+						     clock_deps_name[i]);
+
+		if (IS_ERR(clk)) {
+			if (PTR_ERR(clk) != -EINVAL && PTR_ERR(clk) != -ENOENT)
+				return PTR_ERR(clk);
+		} else {
+			/* Device gets a reference count on the clock */
+			clk_deps[i] = devm_clk_get(dev, __clk_get_name(clk));
+			clk_put(clk);
+		}
+	}
+
+	return 0;
+}
+
 static int stm32mp1_rcc_clocks_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
+	int ret = get_clock_deps(dev);
+
+	if (!ret)
+		ret = stm32mp1_rcc_init(dev);
 
-	return stm32mp1_rcc_init(dev);
+	return ret;
 }
 
 static int stm32mp1_rcc_clocks_remove(struct platform_device *pdev)