[PATCH v1 2/7] soc: imx: gpcv2: Fix power up/down sequence
Adrien Grassein
adrien.grassein at gmail.com
Wed Apr 7 22:21:17 BST 2021
Power up/down sequence were wrongly scheduled.
The ADB400 were triggered at the bad time.
The Handshake were not checked.
The solution is to:
- Split power up and power down sequences;
- Add a register holding the bit to check;
Signed-off-by: Adrien Grassein <adrien.grassein at gmail.com>
---
drivers/soc/imx/gpcv2.c | 235 ++++++++++++++++++++++++++++------------
1 file changed, 163 insertions(+), 72 deletions(-)
diff --git a/drivers/soc/imx/gpcv2.c b/drivers/soc/imx/gpcv2.c
index 8ec5b1b817c7..7afb81489f21 100644
--- a/drivers/soc/imx/gpcv2.c
+++ b/drivers/soc/imx/gpcv2.c
@@ -70,8 +70,11 @@
#define GPC_PU_PWRHSK 0x1fc
#define IMX8M_GPU_HSK_PWRDNREQN BIT(6)
+#define IMX8M_GPU_HSK_PWRDNACKN BIT(26)
#define IMX8M_VPU_HSK_PWRDNREQN BIT(5)
+#define IMX8M_VPU_HSK_PWRDNACKN BIT(25)
#define IMX8M_DISP_HSK_PWRDNREQN BIT(4)
+#define IMX8M_DISP_HSK_PWRDNACKN BIT(24)
/*
* The PGC offset values in Reference Manual
@@ -102,6 +105,8 @@
#define GPC_CLK_MAX 6
+static DEFINE_MUTEX(gpc_pd_mutex);
+
struct imx_pgc_domain {
struct generic_pm_domain genpd;
struct regmap *regmap;
@@ -114,7 +119,8 @@ struct imx_pgc_domain {
const struct {
u32 pxx;
u32 map;
- u32 hsk;
+ u32 hsk_req;
+ u32 hsk_ack;
} bits;
const int voltage;
@@ -127,34 +133,25 @@ struct imx_pgc_domain_data {
const struct regmap_access_table *reg_access_table;
};
-static int imx_gpc_pu_pgc_sw_pxx_req(struct generic_pm_domain *genpd,
- bool on)
+static int imx_gpc_pu_pgc_sw_pup_req(struct generic_pm_domain *genpd)
{
struct imx_pgc_domain *domain = container_of(genpd,
struct imx_pgc_domain,
genpd);
- unsigned int offset = on ?
- GPC_PU_PGC_SW_PUP_REQ : GPC_PU_PGC_SW_PDN_REQ;
- const bool enable_power_control = !on;
- const bool has_regulator = !IS_ERR(domain->regulator);
int i, ret = 0;
- u32 pxx_req;
+ u32 value;
- ret = regmap_update_bits(domain->regmap, GPC_PGC_CPU_MAPPING,
- domain->bits.map, domain->bits.map);
- if (ret) {
- dev_err(domain->dev, "failed to map GPC PGC domain\n");
- return ret;
- }
-
- if (has_regulator && on) {
+ /* Enable regulator if needed */
+ if (!IS_ERR(domain->regulator)) {
ret = regulator_enable(domain->regulator);
if (ret) {
dev_err(domain->dev, "failed to enable regulator\n");
- goto unmap;
+ return ret;
}
}
+ mutex_lock(&gpc_pd_mutex);
+
/* Enable reset clocks for all devices in the domain */
for (i = 0; i < domain->num_clks; i++) {
ret = clk_prepare_enable(domain->clk[i]);
@@ -164,87 +161,178 @@ static int imx_gpc_pu_pgc_sw_pxx_req(struct generic_pm_domain *genpd,
}
}
- if (enable_power_control) {
- ret = regmap_update_bits(domain->regmap, GPC_PGC_CTRL(domain->pgc),
- GPC_PGC_CTRL_PCR, GPC_PGC_CTRL_PCR);
+ /* Map the domain to the A53 core */
+ ret = regmap_update_bits(domain->regmap, GPC_PGC_CPU_MAPPING,
+ domain->bits.map, domain->bits.map);
+ if (ret) {
+ dev_err(domain->dev, "failed to map GPC PGC domain\n");
+ goto disable_clocks;
+ }
+
+ /* Request Power Up of the domain */
+ ret = regmap_update_bits(domain->regmap, GPC_PU_PGC_SW_PUP_REQ,
+ domain->bits.pxx, domain->bits.pxx);
+ if (ret) {
+ dev_err(domain->dev, "failed to command PGC\n");
+ goto unmap;
+ }
+
+ /*
+ * As per "5.5.9.4 Example Code 4" in IMX7DRM.pdf wait
+ * for PUP_REQ/PDN_REQ bit to be cleared
+ */
+ ret = regmap_read_poll_timeout(domain->regmap, GPC_PU_PGC_SW_PUP_REQ,
+ value,
+ !(value & domain->bits.pxx),
+ 0, USEC_PER_MSEC);
+ if (ret) {
+ dev_err(domain->dev, "failed to command PGC\n");
+ goto unmap;
+ }
+
+ /* Disable power control */
+ ret = regmap_update_bits(domain->regmap, GPC_PGC_CTRL(domain->pgc),
+ GPC_PGC_CTRL_PCR, 0);
+ if (ret) {
+ dev_err(domain->dev, "Failed to disable power control !\n");
+ goto unmap;
+ }
+
+ /* request the ADB400 to power up */
+ if (domain->bits.hsk_req) {
+ regmap_update_bits(domain->regmap, GPC_PU_PWRHSK,
+ domain->bits.hsk_req, domain->bits.hsk_req);
+
+ ret = regmap_read_poll_timeout(domain->regmap, GPC_PU_PWRHSK,
+ value,
+ (value & domain->bits.hsk_ack),
+ 0, USEC_PER_MSEC);
+ if (ret)
+ dev_err(domain->dev, "Bad ACK while powering on %s\n",
+ genpd->name);
+ }
+
+ regmap_update_bits(domain->regmap, GPC_PGC_CPU_MAPPING,
+ domain->bits.map, 0);
+
+ /* Disable all clocks */
+ for (i = 0; i < domain->num_clks; i++)
+ clk_disable_unprepare(domain->clk[i]);
+
+ mutex_unlock(&gpc_pd_mutex);
+
+ return 0;
+
+unmap:
+ if (domain->bits.map)
+ regmap_update_bits(domain->regmap, GPC_PGC_CPU_MAPPING,
+ domain->bits.map, 0);
+
+disable_clocks:
+ for (i--; i >= 0; i--)
+ clk_disable_unprepare(domain->clk[i]);
+
+ mutex_unlock(&gpc_pd_mutex);
+ return ret;
+}
+
+static int imx_gpc_pu_pgc_sw_pdn_req(struct generic_pm_domain *genpd)
+{
+ struct imx_pgc_domain *domain = container_of(genpd,
+ struct imx_pgc_domain,
+ genpd);
+ int i, ret = 0;
+ u32 value;
+
+ mutex_lock(&gpc_pd_mutex);
+
+ /* Enable reset clocks for all devices in the domain */
+ for (i = 0; i < domain->num_clks; i++) {
+ ret = clk_prepare_enable(domain->clk[i]);
if (ret) {
- dev_err(domain->dev, "failed to enable power control\n");
+ dev_err(domain->dev, "failed to enable clocks\n");
goto disable_clocks;
}
}
- if (domain->bits.hsk) {
- ret = regmap_update_bits(domain->regmap, GPC_PU_PWRHSK,
- domain->bits.hsk,
- on ? domain->bits.hsk : 0);
- if (ret) {
- dev_err(domain->dev, "Failed to initiate handshake\n");
- goto disable_power_control;
- }
+ /* Map the domain to the A53 core */
+ ret = regmap_update_bits(domain->regmap, GPC_PGC_CPU_MAPPING,
+ domain->bits.map, domain->bits.map);
+ if (ret) {
+ dev_err(domain->dev, "failed to map GPC PGC domain\n");
+ goto disable_clocks;
+ }
+
+ /* request the ADB400 to power down */
+ if (domain->bits.hsk_req) {
+ regmap_update_bits(domain->regmap, GPC_PU_PWRHSK,
+ domain->bits.hsk_req, 0);
+
+ ret = regmap_read_poll_timeout(domain->regmap, GPC_PU_PWRHSK,
+ value,
+ !(value & domain->bits.hsk_ack),
+ 0, USEC_PER_MSEC);
+ if (ret)
+ dev_err(domain->dev, "Bad ACK while powering down %s\n",
+ genpd->name);
+
}
- ret = regmap_update_bits(domain->regmap, offset,
+ /* Enable power control */
+ ret = regmap_update_bits(domain->regmap, GPC_PGC_CTRL(domain->pgc),
+ GPC_PGC_CTRL_PCR, GPC_PGC_CTRL_PCR);
+ if (ret) {
+ dev_err(domain->dev, "Failed to enable power control !\n");
+ goto unmap;
+ }
+
+ /* Request Power Down of the domain */
+ ret = regmap_update_bits(domain->regmap, GPC_PU_PGC_SW_PDN_REQ,
domain->bits.pxx, domain->bits.pxx);
if (ret) {
dev_err(domain->dev, "failed to command PGC\n");
- goto disable_power_control;
+ goto unmap;
}
/*
* As per "5.5.9.4 Example Code 4" in IMX7DRM.pdf wait
* for PUP_REQ/PDN_REQ bit to be cleared
*/
- ret = regmap_read_poll_timeout(domain->regmap, offset, pxx_req,
- !(pxx_req & domain->bits.pxx),
+ ret = regmap_read_poll_timeout(domain->regmap, GPC_PU_PGC_SW_PDN_REQ,
+ value,
+ !(value & domain->bits.pxx),
0, USEC_PER_MSEC);
if (ret)
dev_err(domain->dev, "failed to command PGC\n");
-disable_power_control:
- if (enable_power_control)
- regmap_update_bits(domain->regmap, GPC_PGC_CTRL(domain->pgc),
- GPC_PGC_CTRL_PCR, 0);
-
- if (ret) {
- /*
- * If we were in a process of enabling a
- * domain and failed we might as well disable
- * the regulator we just enabled. And if it
- * was the opposite situation and we failed to
- * power down -- keep the regulator on
- */
- on = !on;
+ if (!IS_ERR(domain->regulator)) {
+ ret = regulator_disable(domain->regulator);
+ if (ret)
+ dev_err(domain->dev, "failed to disable regulator\n");
}
-disable_clocks:
- /* Disable reset clocks for all devices in the domain */
+ regmap_update_bits(domain->regmap, GPC_PGC_CPU_MAPPING,
+ domain->bits.map, 0);
+
+ /* Disable all clocks */
for (i = 0; i < domain->num_clks; i++)
clk_disable_unprepare(domain->clk[i]);
- if (has_regulator && !on) {
- int err;
+ mutex_unlock(&gpc_pd_mutex);
+ return 0;
- err = regulator_disable(domain->regulator);
- if (err)
- dev_err(domain->dev,
- "failed to disable regulator: %d\n", err);
- /* Preserve earlier error code */
- ret = ret ?: err;
- }
unmap:
- regmap_update_bits(domain->regmap, GPC_PGC_CPU_MAPPING,
- domain->bits.map, 0);
- return ret;
-}
+ if (domain->bits.map)
+ regmap_update_bits(domain->regmap, GPC_PGC_CPU_MAPPING,
+ domain->bits.map, 0);
-static int imx_gpc_pu_pgc_sw_pup_req(struct generic_pm_domain *genpd)
-{
- return imx_gpc_pu_pgc_sw_pxx_req(genpd, true);
-}
+disable_clocks:
+ for (i--; i >= 0; i--)
+ clk_disable_unprepare(domain->clk[i]);
+
+ mutex_unlock(&gpc_pd_mutex);
+ return ret;
-static int imx_gpc_pu_pgc_sw_pdn_req(struct generic_pm_domain *genpd)
-{
- return imx_gpc_pu_pgc_sw_pxx_req(genpd, false);
}
static const struct imx_pgc_domain imx7_pgc_domains[] = {
@@ -370,7 +458,8 @@ static const struct imx_pgc_domain imx8m_pgc_domains[] = {
.bits = {
.pxx = IMX8M_GPU_SW_Pxx_REQ,
.map = IMX8M_GPU_A53_DOMAIN,
- .hsk = IMX8M_GPU_HSK_PWRDNREQN,
+ .hsk_req = IMX8M_GPU_HSK_PWRDNREQN,
+ .hsk_ack = IMX8M_GPU_HSK_PWRDNACKN
},
.pgc = IMX8M_PGC_GPU,
},
@@ -382,7 +471,8 @@ static const struct imx_pgc_domain imx8m_pgc_domains[] = {
.bits = {
.pxx = IMX8M_VPU_SW_Pxx_REQ,
.map = IMX8M_VPU_A53_DOMAIN,
- .hsk = IMX8M_VPU_HSK_PWRDNREQN,
+ .hsk_req = IMX8M_VPU_HSK_PWRDNREQN,
+ .hsk_ack = IMX8M_VPU_HSK_PWRDNACKN
},
.pgc = IMX8M_PGC_VPU,
},
@@ -394,7 +484,8 @@ static const struct imx_pgc_domain imx8m_pgc_domains[] = {
.bits = {
.pxx = IMX8M_DISP_SW_Pxx_REQ,
.map = IMX8M_DISP_A53_DOMAIN,
- .hsk = IMX8M_DISP_HSK_PWRDNREQN,
+ .hsk_req = IMX8M_DISP_HSK_PWRDNREQN,
+ .hsk_ack = IMX8M_DISP_HSK_PWRDNACKN
},
.pgc = IMX8M_PGC_DISP,
},
--
2.25.1
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