[PATCH v3 11/12] clk: tegra: Add BPMP clock driver
Jon Hunter
jonathanh at nvidia.com
Mon Aug 22 03:11:57 PDT 2016
On 19/08/16 18:32, Thierry Reding wrote:
> From: Thierry Reding <treding at nvidia.com>
>
> This driver uses the services provided by the BPMP firmware driver to
> implement a clock driver based on the MRQ_CLK request. This part of the
> BPMP ABI provides a means to enumerate and control clocks and should
> allow the driver to work on any chip that supports this ABI.
>
> Signed-off-by: Thierry Reding <treding at nvidia.com>
> ---
> drivers/clk/tegra/Makefile | 1 +
> drivers/clk/tegra/clk-bpmp.c | 565 +++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 566 insertions(+)
> create mode 100644 drivers/clk/tegra/clk-bpmp.c
>
> diff --git a/drivers/clk/tegra/Makefile b/drivers/clk/tegra/Makefile
> index 33fd0938d79e..130df5685d21 100644
> --- a/drivers/clk/tegra/Makefile
> +++ b/drivers/clk/tegra/Makefile
> @@ -22,3 +22,4 @@ obj-$(CONFIG_ARCH_TEGRA_124_SOC) += clk-tegra124-dfll-fcpu.o
> obj-$(CONFIG_ARCH_TEGRA_132_SOC) += clk-tegra124.o
> obj-y += cvb.o
> obj-$(CONFIG_ARCH_TEGRA_210_SOC) += clk-tegra210.o
> +obj-$(CONFIG_ARCH_TEGRA_186_SOC) += clk-bpmp.o
> diff --git a/drivers/clk/tegra/clk-bpmp.c b/drivers/clk/tegra/clk-bpmp.c
> new file mode 100644
> index 000000000000..96cd6becf73e
> --- /dev/null
> +++ b/drivers/clk/tegra/clk-bpmp.c
> @@ -0,0 +1,565 @@
> +#define DEBUG
Do we want DEBUG by default?
> +#include <linux/clk-provider.h>
> +#include <linux/device.h>
> +#include <linux/seq_buf.h>
> +#include <linux/slab.h>
> +
> +#include <soc/tegra/bpmp.h>
> +#include <soc/tegra/bpmp-abi.h>
> +
> +#define TEGRA_BPMP_CLK_HAS_MUX BIT(0)
> +#define TEGRA_BPMP_CLK_HAS_SET_RATE BIT(1)
> +#define TEGRA_BPMP_CLK_IS_ROOT BIT(2)
> +
> +struct tegra_bpmp_clk_info {
> + unsigned int id;
> + char name[MRQ_CLK_NAME_MAXLEN];
> + unsigned int parents[MRQ_CLK_MAX_PARENTS];
> + unsigned int num_parents;
> + unsigned long flags;
> +};
> +
> +struct tegra_bpmp_clk {
> + struct clk_hw hw;
> +
> + struct tegra_bpmp *bpmp;
> + unsigned int id;
> +
> + unsigned int num_parents;
> + unsigned int *parents;
> +};
> +
> +static inline struct tegra_bpmp_clk *to_tegra_bpmp_clk(struct clk_hw *hw)
> +{
> + return container_of(hw, struct tegra_bpmp_clk, hw);
> +}
> +
> +struct tegra_bpmp_clk_message {
> + unsigned int cmd;
> + unsigned int clk;
> +
> + struct {
> + const void *data;
> + size_t size;
> + } tx;
> +
> + struct {
> + void *data;
> + size_t size;
> + } rx;
> +};
> +
> +static int
> +__tegra_bpmp_clk_transfer_atomic(struct tegra_bpmp *bpmp,
> + struct tegra_bpmp_message *msg)
> +{
> + unsigned long flags;
> + int err;
> +
> + local_irq_save(flags);
> + err = tegra_bpmp_transfer_atomic(bpmp, msg);
> + local_irq_restore(flags);
> +
> + return err;
> +}
> +
> +static int
> +tegra_bpmp_clk_transfer_atomic(struct tegra_bpmp *bpmp,
> + const struct tegra_bpmp_clk_message *clk)
> +{
> + struct mrq_clk_request request;
> + struct tegra_bpmp_message msg;
> + void *req = (void *)&request;
> +
> + memset(&request, 0, sizeof(request));
> + request.cmd_and_id = (clk->cmd << 24) | clk->clk;
> + memcpy(req + 4, clk->tx.data, clk->tx.size);
> +
> + memset(&msg, 0, sizeof(msg));
> + msg.mrq = MRQ_CLK;
> + msg.tx.data = &request;
> + msg.tx.size = sizeof(request);
> + msg.rx.data = clk->rx.data;
> + msg.rx.size = clk->rx.size;
> +
> + return __tegra_bpmp_clk_transfer_atomic(bpmp, &msg);;
> +}
> +
> +static int tegra_bpmp_clk_transfer(struct tegra_bpmp *bpmp,
> + const struct tegra_bpmp_clk_message *clk)
> +{
> + struct mrq_clk_request request;
> + struct tegra_bpmp_message msg;
> + void *req = (void *)&request;
> + int err;
> +
> + memset(&request, 0, sizeof(request));
> + request.cmd_and_id = (clk->cmd << 24) | clk->clk;
> + memcpy(req + 4, clk->tx.data, clk->tx.size);
> +
> + memset(&msg, 0, sizeof(msg));
> + msg.mrq = MRQ_CLK;
> + msg.tx.data = &request;
> + msg.tx.size = sizeof(request);
> + msg.rx.data = clk->rx.data;
> + msg.rx.size = clk->rx.size;
> +
> + err = tegra_bpmp_transfer(bpmp, &msg);
> + if (err != -EAGAIN)
> + return err;
> +
> + return __tegra_bpmp_clk_transfer_atomic(bpmp, &msg);
> +}
> +
> +static int tegra_bpmp_clk_enable(struct clk_hw *hw)
> +{
> + struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
> + struct tegra_bpmp_clk_message msg;
> + int err;
> +
> + dev_dbg(clk->bpmp->dev, "> %s(hw=%p)\n", __func__, hw);
> +
> + memset(&msg, 0, sizeof(msg));
> + msg.cmd = CMD_CLK_ENABLE;
> + msg.clk = clk->id;
> +
> + err = tegra_bpmp_clk_transfer(clk->bpmp, &msg);
> +
> + dev_dbg(clk->bpmp->dev, "< %s() = %d\n", __func__, err);
> + return err;
> +}
> +
> +static void tegra_bpmp_clk_disable(struct clk_hw *hw)
> +{
> + struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
> + struct tegra_bpmp_clk_message msg;
> + int err;
> +
> + memset(&msg, 0, sizeof(msg));
> + msg.cmd = CMD_CLK_DISABLE;
> + msg.clk = clk->id;
> +
> + err = tegra_bpmp_clk_transfer(clk->bpmp, &msg);
> + if (err < 0)
> + dev_err(clk->bpmp->dev, "failed to disable clock %s: %d\n",
> + clk_hw_get_name(hw), err);
> +}
> +
> +static int tegra_bpmp_clk_is_enabled(struct clk_hw *hw)
> +{
> + struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
> + struct cmd_clk_is_enabled_response response;
> + struct tegra_bpmp_clk_message msg;
> + int err;
> +
> + memset(&msg, 0, sizeof(msg));
> + msg.cmd = CMD_CLK_IS_ENABLED;
> + msg.clk = clk->id;
> + msg.rx.data = &response;
> + msg.rx.size = sizeof(response);
> +
> + err = tegra_bpmp_clk_transfer_atomic(clk->bpmp, &msg);
> + if (err < 0)
> + return err;
> +
> + return response.state;
> +}
> +
> +static u8 tegra_bpmp_clk_get_parent(struct clk_hw *hw)
> +{
> + struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
> + struct cmd_clk_get_parent_response response;
> + struct tegra_bpmp_clk_message msg;
> + unsigned int i;
> + int err;
> +
> + memset(&msg, 0, sizeof(msg));
> + msg.cmd = CMD_CLK_GET_PARENT;
> + msg.clk = clk->id;
> + msg.rx.data = &response;
> + msg.rx.size = sizeof(&response);
> +
> + err = tegra_bpmp_clk_transfer(clk->bpmp, &msg);
> + if (err < 0)
> + return err;
tegra_bpmp_clk_transfer returns an int, but this function returns a u8.
> +
> + for (i = 0; i < clk->num_parents; i++)
> + if (clk->parents[i] == response.parent_id)
> + return i;
> +
> + return U8_MAX;
Is there any chance the U8_MAX == num_parents? Should we warn here
somewhere?
> +}
> +
> +static int tegra_bpmp_clk_set_parent(struct clk_hw *hw, u8 index)
> +{
> + struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
> + struct cmd_clk_set_parent_response response;
> + struct cmd_clk_set_parent_request request;
> + struct tegra_bpmp_clk_message msg;
> + int err;
> +
> + if (index >= clk->num_parents)
> + return -EINVAL;
> +
> + memset(&request, 0, sizeof(request));
> + request.parent_id = clk->parents[index];
> +
> + memset(&msg, 0, sizeof(msg));
> + msg.cmd = CMD_CLK_SET_PARENT;
> + msg.clk = clk->id;
> + msg.tx.data = &request;
> + msg.tx.size = sizeof(request);
> + msg.rx.data = &response;
> + msg.rx.size = sizeof(response);
> +
> + err = tegra_bpmp_clk_transfer(clk->bpmp, &msg);
> + if (err < 0)
> + return err;
> +
> + /* XXX check parent ID in response */
> +
> + return 0;
> +}
> +
> +static int tegra_bpmp_clk_set_rate(struct clk_hw *hw, unsigned long rate,
> + unsigned long parent_rate)
> +{
> + return 0;
> +}
> +
> +static long tegra_bpmp_clk_round_rate(struct clk_hw *hw, unsigned long rate,
> + unsigned long *parent_rate)
> +{
> + return 0;
> +}
> +
> +static unsigned long tegra_bpmp_clk_recalc_rate(struct clk_hw *hw,
> + unsigned long parent_rate)
> +{
> + return 0;
> +}
> +
> +static const struct clk_ops tegra_bpmp_clk_gate_ops = {
> + .is_enabled = tegra_bpmp_clk_is_enabled,
> + .prepare = tegra_bpmp_clk_enable,
> + .unprepare = tegra_bpmp_clk_disable,
> +};
> +
> +static const struct clk_ops tegra_bpmp_clk_mux_ops = {
> + .get_parent = tegra_bpmp_clk_get_parent,
> + .set_parent = tegra_bpmp_clk_set_parent,
> + .is_enabled = tegra_bpmp_clk_is_enabled,
> + .prepare = tegra_bpmp_clk_enable,
> + .unprepare = tegra_bpmp_clk_disable,
> +};
> +
> +static const struct clk_ops tegra_bpmp_clk_rate_ops = {
> + .is_enabled = tegra_bpmp_clk_is_enabled,
> + .prepare = tegra_bpmp_clk_enable,
> + .unprepare = tegra_bpmp_clk_disable,
> + .set_rate = tegra_bpmp_clk_set_rate,
> + .round_rate = tegra_bpmp_clk_round_rate,
> + .recalc_rate = tegra_bpmp_clk_recalc_rate,
> +};
> +
> +static const struct clk_ops tegra_bpmp_clk_mux_rate_ops = {
> + .get_parent = tegra_bpmp_clk_get_parent,
> + .set_parent = tegra_bpmp_clk_set_parent,
> + .is_enabled = tegra_bpmp_clk_is_enabled,
> + .prepare = tegra_bpmp_clk_enable,
> + .unprepare = tegra_bpmp_clk_disable,
> + .set_rate = tegra_bpmp_clk_set_rate,
> + .round_rate = tegra_bpmp_clk_round_rate,
> + .recalc_rate = tegra_bpmp_clk_recalc_rate,
> +};
> +
> +static int tegra_bpmp_clk_get_max_id(struct tegra_bpmp *bpmp)
> +{
> + struct cmd_clk_get_max_clk_id_response response;
> + struct tegra_bpmp_clk_message msg;
> + int err;
> +
> + memset(&msg, 0, sizeof(msg));
> + msg.cmd = CMD_CLK_GET_MAX_CLK_ID;
> + msg.rx.data = &response;
> + msg.rx.size = sizeof(response);
> +
> + err = tegra_bpmp_clk_transfer(bpmp, &msg);
> + if (err < 0)
> + return err;
> +
> + return response.max_id;
response.max_id is a uint32
> +}
> +
> +static int tegra_bpmp_clk_get_info(struct tegra_bpmp *bpmp, unsigned int id,
> + struct tegra_bpmp_clk_info *info)
> +{
> + struct cmd_clk_get_all_info_response response;
> + struct tegra_bpmp_clk_message msg;
> + unsigned int i;
> + int err;
> +
> + memset(&msg, 0, sizeof(msg));
> + msg.cmd = CMD_CLK_GET_ALL_INFO;
> + msg.clk = id;
> + msg.rx.data = &response;
> + msg.rx.size = sizeof(response);
> +
> + err = tegra_bpmp_clk_transfer(bpmp, &msg);
> + if (err < 0)
> + return err;
> +
> + strlcpy(info->name, response.name, MRQ_CLK_NAME_MAXLEN);
> + info->num_parents = response.num_parents;
> +
> + for (i = 0; i < info->num_parents; i++)
> + info->parents[i] = response.parents[i];
> +
> + info->flags = response.flags;
> +
> + return 0;
> +}
> +
> +static int tegra_bpmp_probe_clocks(struct tegra_bpmp *bpmp,
> + struct tegra_bpmp_clk_info **clocksp)
> +{
> + struct tegra_bpmp_clk_info *clocks;
> + unsigned int max_id, id, count = 0;
> + int err;
> +
> + err = tegra_bpmp_clk_get_max_id(bpmp);
> + if (err < 0)
> + return err;
> +
> + max_id = err;
> +
> + dev_dbg(bpmp->dev, "maximum clock ID: %u\n", max_id);
> +
> + clocks = kcalloc(max_id + 1, sizeof(*clocks), GFP_KERNEL);
> + if (!clocks)
> + return -ENOMEM;
> +
> + for (id = 0; id <= max_id; id++) {
> + struct tegra_bpmp_clk_info *info = &clocks[count];
> +#if 0
> + const char *prefix = "";
> + struct seq_buf buf;
> + unsigned int i;
> + char flags[64];
> +#endif
> +
> + err = tegra_bpmp_clk_get_info(bpmp, id, info);
> + if (err < 0) {
> + dev_err(bpmp->dev, "failed to query clock %u: %d\n",
> + id, err);
> + continue;
> + }
> +
> +#if 0
> + seq_buf_init(&buf, flags, sizeof(flags));
> +
> + if (info->flags)
> + seq_buf_printf(&buf, "(");
> +
> + if (info->flags & TEGRA_BPMP_CLK_HAS_MUX) {
> + seq_buf_printf(&buf, "%smux", prefix);
> + prefix = ", ";
> + }
> +
> + if ((info->flags & TEGRA_BPMP_CLK_HAS_SET_RATE) == 0) {
> + seq_buf_printf(&buf, "%sfixed", prefix);
> + prefix = ", ";
> + }
> +
> + if (info->flags & TEGRA_BPMP_CLK_IS_ROOT) {
> + seq_buf_printf(&buf, "%sroot", prefix);
> + prefix = ", ";
> + }
> +
> + if (info->flags)
> + seq_buf_printf(&buf, ")");
> +
> + dev_dbg(bpmp->dev, " %03u: %s\n", id, info->name);
> + dev_dbg(bpmp->dev, " flags: %lx %s\n", info->flags, flags);
> + dev_dbg(bpmp->dev, " parents: %u\n", info->num_parents);
> +
> + for (i = 0; i < info->num_parents; i++)
> + dev_dbg(bpmp->dev, " %03u\n", info->parents[i]);
> +#endif
> +
> + /* clock not exposed by BPMP */
> + if (info->name[0] == '\0')
> + continue;
> +
> + info->id = id;
> + count++;
> + }
> +
> + *clocksp = clocks;
Nit we could just return the pointer.
> +
> + return count;
We return unsigned int here and not int. Why do we bother returning
count and just store it directly in the bpmp->num_clocks here (see
tegra_bpmp_register_clocks)?
> +}
> +
> +static struct clk_hw *
> +tegra_bpmp_clk_register(struct tegra_bpmp *bpmp,
> + const struct tegra_bpmp_clk_info *info,
> + const struct tegra_bpmp_clk_info *clocks,
> + unsigned int num_clocks)
> +{
> + struct tegra_bpmp_clk *priv;
> + struct clk_init_data init;
> + const char **parents;
> + unsigned int i, j;
> + struct clk *clk;
> +
> + dev_dbg(bpmp->dev, "registering clock %u (%s)\n", info->id, info->name);
> +
> + priv = devm_kzalloc(bpmp->dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return ERR_PTR(-ENOMEM);
> +
> + priv->bpmp = bpmp;
> + priv->id = info->id;
> +
> + priv->parents = devm_kcalloc(bpmp->dev, info->num_parents,
> + sizeof(*priv->parents), GFP_KERNEL);
> + if (!priv->parents)
> + return ERR_PTR(-ENOMEM);
> +
> + priv->num_parents = info->num_parents;
> +
> + /* hardware clock initialization */
> + priv->hw.init = &init;
> + init.name = info->name;
> +
> + if (info->flags & TEGRA_BPMP_CLK_HAS_MUX) {
> + if (info->flags & TEGRA_BPMP_CLK_HAS_SET_RATE)
> + init.ops = &tegra_bpmp_clk_mux_rate_ops;
> + else
> + init.ops = &tegra_bpmp_clk_mux_ops;
> + } else {
> + if (info->flags & TEGRA_BPMP_CLK_HAS_SET_RATE)
> + init.ops = &tegra_bpmp_clk_rate_ops;
> + else
> + init.ops = &tegra_bpmp_clk_gate_ops;
> + }
> +
> + init.num_parents = info->num_parents;
> +
> + parents = kcalloc(info->num_parents, sizeof(*parents), GFP_KERNEL);
> + if (!parents)
> + return ERR_PTR(-ENOMEM);
> +
> + for (i = 0; i < info->num_parents; i++) {
> + /* keep a private copy of the ID to parent index map */
> + priv->parents[i] = info->parents[i];
> +
> + for (j = 0; j < num_clocks; j++) {
> + const struct tegra_bpmp_clk_info *parent = &clocks[j];
> +
> + if (parent->id == info->parents[i]) {
> + parents[i] = parent->name;
> + break;
> + }
> + }
Is it necessary to loop through all the clocks again here? This function
is called from tegra_bpmp_register_clocks() which is already looping
through all the clocks. So for each clock we loop through all the clocks
again.
> + if (!parents[i])
> + dev_err(bpmp->dev, "no parent %u found for %u\n",
> + info->parents[i], info->id);
> + }
> +
> + init.parent_names = parents;
> +
> + clk = clk_register(bpmp->dev, &priv->hw);
IS_ERR?
> +
> + kfree(parents);
> +
> + return &priv->hw;
> +}
> +
> +static int tegra_bpmp_register_clocks(struct tegra_bpmp *bpmp,
> + struct tegra_bpmp_clk_info *clocks,
> + unsigned int count)
> +{
> + struct clk_hw *hw;
> + unsigned int i;
> +
> + bpmp->num_clocks = count;
> +
> + bpmp->clocks = devm_kcalloc(bpmp->dev, count, sizeof(hw), GFP_KERNEL);
> + if (!bpmp->clocks)
> + return -ENOMEM;
> +
> + for (i = 0; i < count; i++) {
> + struct tegra_bpmp_clk_info *info = &clocks[i];
> +
> + hw = tegra_bpmp_clk_register(bpmp, info, clocks, count);
> + if (IS_ERR(hw)) {
> + dev_err(bpmp->dev,
> + "failed to register clock %u (%s): %ld\n",
> + info->id, info->name, PTR_ERR(hw));
> + continue;
> + }
> +
> + bpmp->clocks[i] = hw;
> + }
> +
> + return 0;
> +}
> +
> +static struct clk_hw *tegra_bpmp_clk_of_xlate(struct of_phandle_args *clkspec,
> + void *data)
> +{
> + unsigned int id = clkspec->args[0], i;
> + struct tegra_bpmp *bpmp = data;
> + struct clk_hw *hw = NULL;
> +
> + dev_dbg(bpmp->dev, "> %s(clkspec=%p, data=%p)\n", __func__, clkspec,
> + data);
> +
> + for (i = 0; i < bpmp->num_clocks; i++) {
> + struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(bpmp->clocks[i]);
> +
> + if (clk->id == id) {
> + hw = bpmp->clocks[i];
> + dev_dbg(bpmp->dev, " found %u: %s\n", clk->id, clk_hw_get_name(hw));
> + break;
> + }
> + }
> +
> + dev_dbg(bpmp->dev, "< %s() = %p\n", __func__, hw);
> +
> + return hw;
> +}
> +
> +int tegra_bpmp_init_clocks(struct tegra_bpmp *bpmp)
> +{
> + struct tegra_bpmp_clk_info *clocks;
> + unsigned int count;
> + int err;
> +
> + dev_dbg(bpmp->dev, "> %s(bpmp=%p)\n", __func__, bpmp);
> +
> + err = tegra_bpmp_probe_clocks(bpmp, &clocks);
> + if (err < 0)
> + return err;
> +
> + count = err;
> +
> + dev_dbg(bpmp->dev, "%u clocks probed\n", count);
> +
> + err = tegra_bpmp_register_clocks(bpmp, clocks, count);
> + if (err < 0) {
> + kfree(clocks);
> + return err;
> + }
> +
> + kfree(clocks);
> +
> + of_clk_add_hw_provider(bpmp->dev->of_node, tegra_bpmp_clk_of_xlate,
> + bpmp);
We should check the return code.
> + dev_dbg(bpmp->dev, "< %s()\n", __func__);
> + return 0;
> +}
>
Cheers
Jon
--
nvpublic
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